Final Report Summary - WATER (Winning Applications of nanoTEchnology for Resolutive hydropurification)
Executive Summary:
The overall objectives of WATER were: strengthening the research potential in order to formulate a solid and long term research strategy about nanotechnology applications; increasing our visibility in the ERA; determining an impact on the local economy and society through technology innovation. The focus was on the application of nanotechnology to water treatment, aiming to boost the research potential in this emerging research domain.
Worldwide 1.2 billion people suffer inadequate access to clean water. Nanotechnology is expected to improve the water filtration with lower cost and energy. These were the major motivations for undertaking such an initiative – relying on the local know-how on nanotechnology – aiming to develop novel applications attracting industrial and service assets.
The action included widening of the existing research infrastructures; exchange of know-how and personnel with partners to tackle the issues of the proposed nanotech-based innovation and improve the opportunities of collaborative research; reinforcement of research staff; refinement of management capacities; innovative dissemination actions both for specialists and broader audience; development of a strategic plan for the IP. The multidisciplinary partnership included top class scientists from UK, Spain, France, Germany and Norway, local authorities, representatives of ministerial institutions, water treatment SME and filters technology world Leader company, to guarantee the effectiveness and sustainability of the Action.
WATER aimed to transfer our skills and know-how in the field of nanotechnology to an innovative application relative to water purification. Such action was also contextualized in a joint effort with SME and local administration to achieve in our territory a “culture of water”, that means not only the development of a technology for water purification, but also the growth of a broader concept of water management.
A recent review article “Solar photocatalysis for water disinfection: materials and reactor design”, by D.A. Keane et al. (Catalysis Science & Technology 4, 1211 (2014)) claims that “...access to clean drinking water is a human right according to UN regulations. The significance of using immobilised catalysts over the catalyst powder in slurries is also highlighted. It is noted that, despite encouraging early field studies, the commercialisation and mass production of solar photocatalysis systems remains highly challenging.”
With respect to the state of the art, we have critically examined the advantages of some approach and have decided to focus our efforts into the realization of photocatalytic materials, immobilized in a matrix, that are active in the solar light. The technological impact was represented by the realization of photocatalytic nanomaterials, up-scalable to industrial production, to be used in water purification systems. This innovation was coordinated with some SMEs, that participated to the project with an official role ratified by a MoU. This technologic development promises to sustain the economy of the Ionic Sicily, by improving the quality of the sea water through innovative treatment of waste water, flowing into the ground of coastal towns as allowed by the local legislation.
Our scientific strategy had an impact in terms of 1) scientific production (28 JCR publications), 2) visibility (20 presentations at international conferences, 4 awards, several independent mentions on the media) 3) cultural growth of the team (attendance to top level courses on management and communication), 4) relationship with SME (2 MoU signed, 2 companies among the partners). Furthermore, WATER gave an impulse to induce a change of the local mentality, by the affirmation of a long-term vision and strategy in a common scientific and social context, hopefully to see a new generation growing in a fairly productive environment, projected towards the desired change of mentality. WATER has represented a breakthrough, but the tsunami it caused has still to calm down.
Project Context and Objectives:
The Seventh Framework Programme should contribute towards promoting growth, sustainable development and environmental protection [DECISION No 1982/2006/EC].
Worldwide, 1.2 billion people lack access to sufficient amount of clean water and 2.6 billion people lack adequate sanitation. Having adequate water supplies, and removing pathogens, chemicals and new generation contaminants with high throughput at low cost is a growing challenge around the world. In particular, this issue is critical for a region entirely washed by the sea and affected by long periods of droughts, such as Sicily. Nanotechnology is expected to improve the actual water filtration technology and also drive down the prohibitively high costs of water cleaning.
We identified two great resources in the ionic area of Sicily: the Sea and the bright tradition of the Physics – and more recently the skills developed in the field of nanotechnology – at CNR Catania. These two resources met within the frame of a successful action in terms of water treatment by nanotechnology. CNR Catania has got a strong background in materials science and nanotechnology with specific application to electronic devices, photonics and energy. Silicon quantum dots, metallic nanoparticles, Carbon nanotubes, semiconductor nanowires, nanoporous membranes, functional organic metamaterials are just a few examples of nanostructures for which the scientific research in Catania is famous and esteemed around the world. The local know-how on nanomaterials contributed to develop – with the focused investments of WATER – novel applications that could attract new industrial and services assets and have a broad impact on the society.
Aci Castello, a small town in the Catania area with a protected sea region of EC interest, and the Marine Protected Area “Isole Ciclopi” have been selected as a pilot case to study the effect of nanotechnology applications for water treatment systems. The local authorities have been involved in the project since the early stage and they supported the action plan by providing documents about the sea water state. This was an innovative approach for our applied research that will have in this case a determinant social impact. In addition, the dialogue between science and society in Sicily should be intensified in order to develop a science and research agenda that meets citizens' concerns, and is aimed to reinforcing a public confidence in science.
A worldwide leader in water filtration system, ATLAS Filtri, supported WATER, giving the great added value of tangible purpose of technology transfer and the potential of effective application of the innovation produced by WATER.
We focused on the realization of smart functional photocatalytic materials, with the final outcome of water purification devices and systems up-scalable to industrial-scale production and application. WATER aimed to transfer our skills and know-how in the field of nanotechnology to an innovative application relative to water purification. Such action should also be contextualized in a joint effort with SME and local administration to achieve in our territory a “culture of water”, that means not only the development of a technology for water purification, but also the growth of a broader concept of water management.
A recent review article “Solar photocatalysis for water disinfection: materials and reactor design”, by D.A. Keane et al. (Catalysis Science & Technology 4, 1211 (2014)) claims that “...access to clean drinking water is a human right according to UN regulations. The major advantage of using photo-reactors is that they enhance disinfection by increasing photon flux into the photocatalyst. The significance of using immobilised catalysts over the catalyst powder in slurries is also highlighted. It is noted that, despite encouraging early field studies, the commercialisation and mass production of solar photocatalysis systems remains highly challenging.” With respect to the state of the art, we have critically examined the advantages of some approaches and have decided to focus our efforts into the realization of photocatalytic materials, immobilized in a matrix, that are active in the solar light. One of the main objectives, also in terms of size of the investment, was the realization of a new laboratory, equipped with state of the art instrumentation, for the synthesis of such photoactive nanomaterials to be used for water purification. For this action, we upgraded our facilities with a new research infrastructure for production of nanostructures on a large scale, i.e. the Atomic Layer Deposition (ALD) methodology. It has been demonstrated by Sandia National Laboratories and University of New Mexico that self-assembly and ALD can advance the field of membrane technology for water filtration.
During the second project year we have completed the realization of the facility, the installation of the equipment and the training for their use. The laboratory now is fully running and many materials produced by its equipment have been already synthesized and tested. Even a million Euro lab is nothing without the diligence of skilled and motivated scientists. Another important objective of WATER was that of training a group of top level researchers to operate in a fair atmosphere, with an efficient organization of roles and responsibilities. We indeed obtained this result, by forming an harmonious group where a sound spirit of competition exists, but always shaped to correctness and intellectual honesty. This situation was reached thanks to a delegating style permeating the team, with clear assignment of tasks, roles and merits, to a patient activity of interconnection between the subjects of the group and to an effort towards the establishment of an effective flow and exchange of information.
We have invited the President of CNR, Luigi Nicolais, to visit the WATER laboratory and had the great honor to receive his visit on January, 16th 2015. President Nicolais congratulated for the realization of this leading edge facility and appreciated the potential of the materials realized by our new equipment.
The main objective of the “Research Potential” program which we applied to in 2012 with the WATER proposal was “to unlock the research potential” of the applicant. We believe to have achieved such main objective thanks to the EC funding and to the careful fulfillment of the action plan negotiated with the EC. Our skills and scientific background were combined with state of the art equipment and a correct dose of visibility, as well as corroborated by efficient twinning measures and reinforcement of the human capital, both in terms of resources and of their cultural growth.
This was not only a research project, but a coordinated action led together with some actors of the local territory, such as the municipality of Aci Castello or the Marine Protected Area “Isole Ciclopi”. A hard task was to make the local scientific community understand that a Coordination Action is not only a research project, but a global social, economic and certainly also scientific action, led together with supporting partners and actors of the territory, aiming also to an intense dissemination of the ideas which the action relies on and of the relative achievements. While twinning with the supporting partners is a chance of cultural growth and scientific specialization, an effective dissemination plan to a broad public can favor a close link between scientific research and society. The dialogue between science and society in our territory was hence intensified in order to develop in the local society a better established feeling of trust in science and research.
In order to achieve these objectives an intense dissemination campaign was launched by WATER. A bright example is represented by the “Water Day”, a festival on science and water organized by our team in Aci Castello, the Municipality involved in the project. This event was devoted to get closer to the people, by showing the research results and explaining in simple words how such scientific highlights can be useful for the daily life. The methodology and the language for an effective conversation with the people, both adults and children, were refined along the WATER life thanks to the Communication course we attended at the beginning of the project. We are now definitely able to find the correct way to construct a fruitful dialogue with citizens having no scientific background, but eager to learn new concepts and driven by the curiosity of the research highlights. More than one thousand participants came to see what water, science and entertainment share in common. The Municipality supported such initiatives with the publicity on its facebook page as well as with the tweets of the Mayor. Further sustain to the dissemination initiatives always came from our stakeholders, both companies (Atlas Filtri, New Ecotecnica Sud, Fonte Nuova, Plastica Alfa) and public institutions (Marine Protected Area “Ciclopi Islands”). The relationship with these stakeholders was regulated by the drafting of a Memorandum of Understanding.
Another important objective is that of technologic transfer. The effective application of the innovation produced by WATER has been carefully examined together with the top technical and marketing management of the companies that signed a MoU, giving rise to the definition of a prototype for obtaining drinkable water from contaminate sources. Furthermore, from the basic scientific point of view we are making an effort to develop new synthesis methods that are relevant both for being published in high impact factor journals and for attracting the industrial interest for realizing conceptually new products. An example is represented by the growth of nanostructures in the Atomic Layer Deposition (ALD) system installed by the WATER funding at temperatures as low as 40 °C, potentially compatible with thermoplastic materials on which integrate them.
The conclusive objective, particularly related to the last semester, was the definition of an evaluation relative to the action. Indeed, this evaluation already untied since the early stage with a careful SWOT analysis ad, along the life of the project, with a continuous check of the success indicators reported in the work plan. The last phase of this evaluation process was represented by the meeting with three independent experts nominated by the EC, who came to visit the WATER team and the facilities realized by the EC funding. This moment of debate was tough, but also rewarding, and led the team to make a deep analysis of the achievements and of the unexpected consequences, positive or negative, of the action.
Project Results:
Description of the main S&T results
An intense research activity was performed during the WATER life, even though this was a coordination action. The reason lies in the technical boost given to the research level of our CNR Unit by the new equipment and in the psychological drive originated by the challenge of tackling new topics, i.e. water purification by functional photocatalytic nanomaterials. Thanks to the human resources sustained by the WATER funds, a significant effort was put in opening new research programmes. A synthesis of the main results is reported in this document.
Plasmon enhanced photocatalysis in TiO2/Ag/TiO2 nanocomposite films
Due to its wide band-gap, TiO2 absorbs only in the UV range of the electromagnetic spectrum. However, sunlight contains a small amount of UV photons (~5%). Thus, in the last 20 years have been developed several strategies devoted to increase the efficiency of titanium dioxide under visible (solar) irradiation. Among the most extensively studied methods, we are interested, in particular, in the use of plasmonic metal nanostructures. Plasmonics exploits the physics of collective oscillations of free electrons in metals, induced by the interactions with electromagnetic radiation, typically in the visible range. Plasmonic metal nanostructures can interact with a photoactive substrate increasing the probability of light absorption, leading o field enhancement and non-linear effect in the vicinity . The advantage of the formation of e-/h+ pairs, close to the semiconductor surface, is that these charge carriers are readily separated from each other and easily migrate to the surface, where they can perform photocatalytic transformations.
To further enhance the plasmonic effects of metal nanostructures, we engineered the optical response and thickness of a Ag/TiO2 nanocomposite film. Our results clearly demonstrate that the proper thickness engineering is the key to take simultaneously advantage of spectrally and spatially localized surface plasmon resonance (LSPR) and optical amplification. Indeed, combining TiO2, a high refractive index material, with Ag, known for its excellent plasmonic properties, we obtained a highly enhanced optical response in the visible range. Pursuing this idea, we obtained, via sequential sputtering and annealing, a TiO2/Ag/TiO2 nanocomposite showing photocatalytic activity under visible illumination according to the discoloration of the Methylene blue dye. We compared two TiO2/Ag/TiO2 nanocomposite films with and without the field enhancement conditions induced by the thickness engineering of the film. We also measured the activity of a bare TiO2 film whose 10 nm-thick superficial layer was prepared following the same procedure of the capping layer of Ag NPs. MB degradation occurs under irradiation; therefore we report also the degradation of a vessel not containing photocatalytic material as reference. We observed that, as expected, TiO2 is not active under visible illumination. The fundamental result of the test was that, despite having the same composition and superficial morphology, the two TiO2/Ag/TiO2 nanocomposite film showed completely different behavior. In particular, the film matching the plasmonic field enhancement conditions is able to decompose the MB dye, showing a good photocatalytic activity in the visible range, while the film outside these conditions appeared to be not active. These results underline the importance of a proper optical engineering of the supporting matrix for plasmon enhanced applications. Such substrate is an ideal candidate for solar-driven photocatalytic reactions.
Improvement of the photocatalytic efficiency of nanostructured TiO2
As part of the WATER project, we have opened several lines of research centered on the titanium dioxide. The aim was to increase the photocatalytic efficiency of the material in order to make it more efficient in the purification treatment of the water. The methods to enhance the photocatalytic properties of TiO2 are mainly based on the inhibition of the photo-generated electrons–holes recombination, on the increase of the exposed surface area, and on the decrease of the TiO2 band-gap energy that hollows the absorption of visible light to generate electrons-holes couples. In this context, we have obtained the following results:
We propose a ground-breaking approach by an upside-down vision of the Au/TiO2 nano-system in order to obtain an enhanced photocatalytic response. The system was synthesized by wrapping Au nanoparticles (8 nm mean diameter) with a thin layer of TiO2 (4 nm thick) deposited by atomic layer deposition (ALD). The novel idea of embedding Au nanoparticles with titanium dioxide takes advantage of the presence of metal nanoparticles, in terms of electron trapping, without losing any of the TiO2 exposed surface, so as to favor the photocatalytic performance of titanium dioxide. The remarkable photocatalytic performance together with the stability of the nano-system was demonstrated by degradation of the methylene blue dye in water. The non-toxicity of the nano-system was established by testing the effect of the material on the reproductive cycle of Mytilus galloprovincialis in an aquatic environment. The originally synthesized material was also compared to conventional TiO2 with Au nanoparticles on top. The latter system showed a dispersion of Au nanoparticles in the liquid environment, due to their instability in the aqueous solution that clearly represents an environmental contamination issue. Thus, the results show that nanometric TiO2 wrapping of Au nanoparticles has great potential in eco-friendly water/wastewater purification.
Another possibility to increase the photocatalytic activity of titanium dioxide is given by the use of nanostructured systems, such as: nanoparticles, nanotubes, nanowires, etc... TiO2 nanostructures can offer advantages such as high surface-area-to-volume ratio, enhancing in this way the amount of the photo-generated charges. However, there are some issues that strongly limit their application: poor light penetration due to nanostructures agglomeration and the post-recovery of the same after the water treatment. Based on the above-mentioned considerations, we studied the photocatalytic activity of a TiO2 thin film covering a nanostructured Si template in degrading dyes in water. The titania film (10 nm thick) was deposited by Atomic Layer Deposition. This approach avoided the use of nanoparticles and their consequent dispersion in water. The obtained results show that the excellent conformality of the titania film on high aspect-ratio Si nanostructures is responsible for the improved efficiency in degrading dyes in water. In particular, the nanostructured TiO2 exhibited a photo-degradation reaction rate for the methylene blue and methyl orange that is approximately 3 and 12 times the rate of the TiO2 film with the same macroscopic area, respectively. Thus, our results demonstrate that the TiO2 thin film coating of nanostructured surface can be efficiently used for water treatment reactors.
The development of photocatalysts that can operate under visible light will allow the use of the main part of the solar spectrum. One useful approach has been to dope TiO2, in particular with nitrogen, carbon, transition metals. Metal ion implantation has been reported as an effective method to improve the visible light response of TiO2. However, we have reported that ion implantation is responsible of the loss of the photocatalytic efficiency in the UV region, due to the kind of defects introduced. Recently, black hydrogenated TiO2 has received extensive interest, and it is considered to have a great potential due to its extremely enhanced absorption in the visible and infrared region. The synthesis of hydrogenated titania usually involves commercial Degussa P25 TiO2 or titania nanorods and nanotubes. The hydrogenation is always carried out in a tube furnace, with a temperature in the range of 200–550ºC, in a high pressure H2 atmosphere (up to 20 bar), and for an exposition time from 3 h to 5 days. We employed hydrogen peroxide etching of Ti films as an easy, rapid, and low-cost method to synthesize hydrogenated TiO2 nanoplumes with significant photocatalytic properties under UV and VIS light irradiation. This TiO2 nanostructure and its synthesis are totally original. In particular, the synthesized nanoplumes have a significant efficiency in degrading methylene blue organic compound and a good antibacterial activity under VIS light irradiation. The presented synthesis process may be applied for the fabrication of efficient hydrogenated photocatalytic materials as an alternative to high temperature and high pressure approaches. In addition, the proposed method is industrially scalable, with relatively low cost, and with no environmental impact.
Advanced synthesis of ZnO for photocatalysis
The uses of ZnO as a photocatalytic degradation material for environmental pollutants has been extensively studied, because of its nontoxic nature, low cost, and high photochemical reactivity. ZnO probably has the most abundant forms of any known material. ZnO has emerged to be more efficient catalyst as far as water detoxification is concerned because it generates H2O2 more efficiently, it has high reaction and mineralization rates, and also it has more numbers of active sites with high surface reactivity. The properties of ZnO are strongly dependent on its structure, including the morphology, aspect ratio, size, orientation, and density of crystal. We focused our research in three different materials. The photocatalytic performance of the investigated materials was tested in detail by the photo-degradation of Methylene Blue (MB) and phenols in water.
ZnO nanofibers (ZnO NF) with and without Pt nanoparticles (NPs) fabricated by the electrospinning method. We synthetized two different kinds of nanofibers: with and without Pt Nanoparticles. The synthesis of the Pt NPs was performed by pulsed laser ablation in water. The solution, contained a Zinc precursor and eventually 1% of Pt NPs, was electrospun using a commercial electrospinning apparatus. In order to remove the polymer after the electrospinning process, the composites were annealed at 500 °C, for 1 h, in a conventional furnace under a controlled oxygen atmosphere (2.5 l/min). The SEM and TEM analysis showed that both electrospun ZnO nanofibers, enriched with Pt NPs and without them, have a mean radius ~ 50 nm. The addition of Pt nanoparticles improves the nanofibers photocatalytic activity of ZnO in the degradation of methylene blue. In particular, the Pt-ZnO NF exhibited a photo-degradation reaction rate that is ~ 40 % higher than that observed for mere ZnO nanofibers. The fibrous structure, that facilitate the contact of nanofibers with the dye, together with the presence of Pt, that improves the separation of charge carriers, makes Pt-ZnO a promising candidate for photocatalytic applications.
ZnO nanorods (ZnO NR) synthetized by the Chemical Bath Deposition (CBD) technique. ZnO seed layers were deposited on Si substrate by ALD, with a Picosun R-200 Advanced system. During the deposition, the temperature was kept at 300 °C. The deposition cycles was varied from 25 to 250 cycles, so to obtain three different thicknesses: 3 nm, 10 nm and 30 nm. Aligned ZnO NRs arrays were synthesized using a CBD method at atmospheric pressure. ZnO NR grown by CBD onto extra-thin (3 nm) and extra-smooth (RMS < 0,2 nm) ALD seed layers have shown excellent photo-degradative properties towards methylene blue dye and phenols. The thickness (and related roughness) of ALD seed layer is proven effective to trigger the ZnONRs overall density, ultimate responsible for the observed variation of photocatalytic activity (towards methylene blue and phenol degradation in water) of obtained supported ZnO nanostructured.
ZnO thin films (ZnO TFs) deposited by Atomic layer deposition at low temperature. ZnO films with different thicknesses (from ~ 9 to ~ 48 nm) were deposited. During the deposition, the temperature was fixed at 40, 80 or 120 °C in order to understand the effect of the temperature in the ZnO films crystallinity and morphology. XRD analyses proved the polycrystalline structure of the ZnO films, even for the samples deposited at 40 °C, despite the low deposition temperature. The photocatalytic activity of the materials was investigated, by the MB degradation, as a function of the film thickness and the deposition temperature. We found that for ZnO films deposited at 80 °C a surface region of ~ 20 nm contributes the charge carriers to the photoreactions. The trend of the photocatalytic activity with the deposition temperature appeared strongly dependent on the crystallographic orientation of the films. In particular, the samples deposited at 80 °C showed the best photocatalytic performance, since the (002) orientation prevails. Finally, we fabricated flexible photocatalytic films by depositing by ALD at 80 °C a thin film of ZnO on polyethylene naphtalate (PEN). The films showed a significant efficiency in the photo-degradation of MB and phenols in water.
Polymeric nanocomposites for water purification
TiO2 nanostructures have a great potential as very efficient photocatalysts due to their large surface area, in fact a higher surface/volume ratio increase the reactivity. However, significant limitations exist for the use of nanomaterials due to their impact on human health and ecosystems. Until now, available information is insufficient to determine the toxicity or the highest allowable concentration of a particular nanomaterial in drinking water. In addition, if nanomaterials are applied in the form of dispersion, after water treatment, an efficient separation process is required. Slurries of TiO2 are often treated in photoreactors, which produce fast water purification from organic pollutants and bacteria. Nevertheless, such plants require a high energy consumption and a secondary filtration to separate the nanomaterials from water. Our approach is alternative to the use of nanomaterials dispersed in water, it based on the incorporation of several nanomaterials into polymeric composites as a valid solution to overcome these problems.
Such nanocomposites were synthesized using poly (methyl methacrylate), a common thermoplastic material, as polymer matrix. These composites with PMMA are stable, harmless, cheap and they can be realized in a freestanding form by a simple and low-cost method of solution casting, allowing a potential industrial application as efficient tools for the removal of organic and bacterial contaminants from water. The photocatalytic activity of the samples was evaluated by the degradation of two different dyes (methylene blue and methyl orange) and phenols in an aqueous medium adapting the methodology with the current ISO10678:2010 test, as well as we tested the antibacterial activity by measuring the survival rate of Escherichia coli, as a model organism, after exposure to light activated samples.
PMMA films with different contents of TiO2 nanoparticles were realized and tested. They display a very high UV photocatalytic efficiency, compared to other immobilized photocatalytic materials reported in the recent literature. In addition, the stability of these photocatalysts was evaluated re-using the same fragment of PMMA/TiO2 film for the degradation of methylene blue. The photocatalytic activity does not significantly change after several cycles, suggesting that PMMA nanocomposites can be efficiently recycled and reused for repeated cycles without loss of efficiency. No NPs were released from the material as attested by the absence of any photocatalytic activity when the samples were extracted from the solution. For the antibacterial activity, after 1h exposure to the PMMA/TiO2 film (1 cm2) with 15wt% NPs and UV, E. coli survival rate has been reduced up to ~30%.
Furthermore, to obtain an higher degradation rate, titanium dioxide nanoparticles combined with single walled carbon nanotubes (SWCNTs) were embedded in the polymeric films. SWCNTs act as acceptor of electrons, improving the charge separation process; in this way a significantly higher photocatalytic efficiency under UV irradiation was obtained, compared to the systems with TiO2 only.
The main problem of the TiO2, that limits its application especially in the large-scale industry, is the value of its band gap ̴ 3.2 eV), allowing an absorption only in the ultraviolet range (λ < 387 nm). Photoactive materials even under visible light were synthesized thanks to the functionalization of the TiO2 nanoparticle surface with meso-tetraphenylporphyrin-4,4’,4’’,4’’’-tetracarboxylic acid (TCPP) as dye sensitizer. The efficiency of degradation of methylene blue under visible light in contact with this sample is comparable to the efficiency obtained with the film of PMMA with only TiO2 nanoparticles, but under UV light. The antibacterial activity of the films with the porphyrin was tested with a visible lamp. The visible light promotes bacterial growth, in fact bacteria exposed to visible light only and to PMMA and visible light were able to double after 1 hr exposure, if compared to the untreated sample. However, in the presence of the film with TiO2 impregnated with the porphyrin, the E. coli survival rate has been reduced up to around 60%. These results are crucial for the application of these nanocomposites as solar photocatalysts, very useful for portable applications and/or use in disadvantaged areas.
Photoactive nanocomposites by direct transferring of anodic TiO2 nanotubes to commodity thermoplastics
TiO2 nanotubes (TNT) have demonstrated to be a versatile nanostructure for biomaterials, clean energy and water remediation applications at lab-scale. However, the cost of titanium and the poor mechanical properties of the nanotubes hinder their adoption at large scale. In this research line, we developed a straightforward and scalable method for transferring photoactive anodic TiO2 nanotubes from titanium foils to commodity thermoplastic polymers (TP), polypropylene (PP), polyethylene terephthalate(PET), polycarbonate (PC), and polymethylmetacrylate, allowing the reusing of titanium. The obtained composites present comparable photoactivity (ISO-10678:2010) and antibacterial properties than TiO2 nanotubes on titanium with the advantage to be pliable. This approach allows a low-cost fabrication of a photoactive nanocomposite material. After the synthesis, the composites shows proper retention of the TNT, mechanical flexibility and pliability.
The Photonic efficiency (PE), measured by the ISO-10678:2010 protocol (Fine ceramics — Determination of photocatalytic activity of surfaces in an aqueous medium by degradation of methylene blue. ISO 10678:2010(E). International Organization for Standardization (2010). Switzerland), resulted to be about 0.025 %, comparable with that of a commercial product. The TNT/TP compositesl show bactericide properties.
We have hence obtained an economic, easy and accessible methodology for transferring TNT from Ti foils to various commodity TP to obtain pliable photoactive nanocomposites with the possibility of reusing the Ti. This, together with the simplicity and the possibility to use basic equipment and recycled raw materials, makes the presented technique a promising route for the industrial synthesis of these composites not only for environmental application but also in different fields such as sensing and biomaterials.
Carbon nanotubes mixed with titania nanoparticles
Common photocatalytic materials are semiconductor oxides. Among these materials, the most widely used in water splitting technique and in photocatalysis is titanium dioxide (TiO2) because of its easy availability, long-term stability and relative non-toxicity. One of the limiting factor of TiO2 photocatalytic activity is the fast electron-hole recombination times (10-9 s) with respect to typical time scale of chemical interactions (10-8 ÷ 10-3 s) induced by the photocatalyst surface on the molecules in contact with it. A lot of strategies have been proposed to overcome these limitations. One of these approaches is to increase the lifetime of the electron-hole pair by trapping the electrons, and this can be achieved by integrating TiO2 with transition metal ions or heavy metals or carbonaceous materials.
Among carbon based materials, nanotubes (CNTs) are widely used, coupled with TiO2, for the improvement of the photocatalytic efficiency of the semiconductor oxides. In many works, mixed CNT-TiO2 nanoparticle powders are dispersed in solution, but this process has some drawbacks, such as the permanency of the photocatalytic materials in the solution and the difficulty to reuse the same photocatalyst more than once. The deposition of nanomaterials with photocatalytic properties on a suitable substrate, without significant release of CNTs and nanoparticles in the water to be purified, would allow to go beyond these problems.
We have used electrophoretic deposition (EPD) to deposit anatase TiO2 nanoparticles and multi-walled Carbon Nanotubes (MWCNTs) composite layers on Pt/SiO2/Si substrates. EPD is a cost-effective method usually requiring a simple equipment allowing to fabricate uniform coatings with excellent macroscopic homogeneity.
The photocatalytic properties of mixed layers, with different MWCNTs/TiO2 weight ratios (CNT:np-TiO2 ratio in solution increases between 0.1 and 0.75) and TiO2 nanoparticles were compared by using the photocatalytic discoloration of Methylene Blue (MB) under UV-Vis irradiation provided by a solar simulator. The composite layers were characterized by scanning electron microscopy (SEM), Energy Dispersive X-ray analysis (EDX), and photoluminescence (PL) measurements in order to explain the different photocatalytic behaviours observed for each material.
The sample with the best photocatalytic properties is found to be the one prepared with a CNT:TiO2 ratio of 0.5 and it also shows the lowest PL intensity. Indeed both the effects can be related to the electron trapping phenomenon that induces a hindering of the electron-hole pair recombination. For the largest relative amount of CNTs (CNT:TiO2 ratio of 0.75) the photocatalytic efficiency decreases and PL peak intensity increases again. Both the effects could be related to an excess of CNTs covering the TiO2 surface.
Any possible reduction of the MB concentration due to adsorption phenomena on the catalyst surface has been evaluated by keeping MWCNT/np-TiO2 composite samples in MB solution in dark conditions at different temperatures (at room temperature and heating the solution on a hot plate at 50°C) for the same time used in the irradiation process. No significant MB reduction due to adsorption phenomena on the photocatalyst surface has been observed in all the solutions by absorbance measurements, therefore the observed MB reduction is imputable only to degradation of the molecule and not to a mere adsorption on the photocatalyst surface or to a temperature effect.
Furthermore, the possibility to use the same samples more than once was verified by repeating the photocatalytic process (immersion of the photocatalyst in MB solution and irradiation) for three times and evaluating the efficiency of the process: the effect on the MB degradation remains unchanged at least for three consecutive processes.
Graphene oxide and graphene oxide reduced by pulsed laser ablation.
In general, graphene-based materials for large-scale production can be obtained from graphene oxide (GO) by reducing the number of oxygen functional groups by means of suitable treatments. The composition and the structure of GO and reduced GO depend on the synthesis and reduction methodologies.
Within the WATER Project, GO and modified GO have been investigated in order to better understand their chemical/physical properties and use them suitably for applications in water purification. We prepared GO by a modified Hummers method and reduced it by pulsed laser irradiation using visible wavelength (532 nm). Transmission electron microscopy analyses were performed and dual electron energy-loss spectra were acquired in different regions of GO and reduced GO (rGO) flakes. Experimental results showed a series of characteristic peaks related to C and O K-edge shells. Density functional theory calculations of the high-loss region of the electron energy loss spectra at atomic level enabled a reliable correlation between the observed experimental peaks to the presence of different oxygen functional groups on the graphene surface and the corresponding atomic configurations.
In particular, we were able to distinguish among the features related to C atoms in the vicinity of C–OH bonds, C-O-C bonds and O-in-vacancy sites. In the explored areas, the percentage of epoxy groups (C-O-C) prevails over the hydroxyl groups. Moreover the π2* peak was indicative of highly oxidized regions.
The oxygen EELS spectrum can be explained by the presence of functionalities with different configurations and local concentrations, confirming the inhomogeneous nature of graphene oxide. The differences between GO and rGO observed in the C and O K-edges spectra were satisfactorily explained by theoretical calculations.
Mixing of graphene oxide/reduced graphene oxide with titania nanoparticles
Recently, graphene and graphene oxide (GO) are drawing much attention as alternative materials for dyes adsorption. Graphene is defined as a flat monolayer of sp2 bonded carbon atoms, packed tightly into a two-dimensional honeycomb lattice. GO is generally prepared by chemical oxidation of graphite powder resulting in extended graphene sheets decorated with epoxy and hydroxyl functional groups in the basal plane and carboxylic acid groups at the edges. These groups confer high hydrophilicity and negative charge density to GO, favouring the adsorption of cationic species as the methylene blue (MB) azo-dye, due to electrostatic interaction. MB can form different aggregates on GO producing maxima of light absorption at specific wavelengths.
GO and reduced GO (rGO) by pulsed laser ablation in liquid (PLAL), using visible wavelength (532 nm), were tested for dye removal. PLAL, with respect to other reduction methods, is more environmentally friendly and allows to tune gradually the density and quality of the oxygen functional groups on GO. In addition, we have tested PLAL as a new, simple and green method for the synthesis of GO (rGO)–TiO2 composite materials.
The interest for this kind of hybrid materials arises from the photocatalytic activity of TiO2 for water purification. Hybrid compounds containing GO and TiO2 (P25) nanoparticles were realized to get a better dispersion of the semiconductor oxide on a wide surface area and to increase the absorption of light in the visible range. Anyway, since GO shows higher MB adsorption capacity than other absorbent materials, such as carbon nanotubes and activated carbon, it is important to test also the adsorption properties of the hybrid compounds.
We have tested the ability of GO-(rGO-)TiO2 composites to remove a cationic dye such as MB from water by simple adsorption phenomena. In particular GO was irradiated by laser for different times (15’, 60’ and 180’) and the produced rGO materials are identified as rGO15, rGO60 and rGO180 respectively.
Interestingly, the aggregation of dye cations varies depending on GO superficial characteristics and therefore it is interesting to study and compare the efficiency of GO and its laser reduced forms for the adsorption of MB in water. When GO and rGO were added to the MB solution an aggregation phenomenon immediately occurred and the concentration of the residual MB rapidly dropped down.
MB aggregation depends on GO concentration that was varied between 10 and 100 mg/l: at the lowest concentration, the peak at 577 nm indicates the formation of MB trimer while the second peak at 668 nm is due to the monomeric form. As the GO concentration is increased the maximum of the curves shifted to higher wavelength due to a lower MB aggregation on the GO layers: the peak related to the trimer disappears and the peaks of dimer and monomer are predominant.
For 70 mg\l GO a shoulder at 577 nm is still present indicating the presence of trimers. MB adsorption occurs by three regimes corresponding to (1) isolated MB on GO, (2) MB molecules interacting as “H” dimers on GO and formation of aggregates, and (3) MB saturation of GO surface and subsequent precipitation. The three regimes depend on the relative concentration of GO layers and MB molecules in water: when GO concentration is high enough, MB molecules can distribute homogeneously on the GO surface without interacting with other molecules; as the GO concentration is reduced the adsorbed MB can interact more easily and aggregation occurs, with the formation of trimers. In addition, the MB aggregation on GO depends on oxygen distribution on its surface: the number and size of aggregates decreased in favour of monomers with increasing the reduction time in accordance with the lower charge density of rGOs with respect to GO. The absorption of cations is reduced and the large distances between negative neighbouring sites cause relatively large distances between adsorbed cations. The effect of lowering the charge density of GO is detectable by MB adsorption, and is also observable for GO/rGO180-P25 solutions.
For 90 mg\l TiO2 solution no MB adsorption takes place, whereas it occurs immediately if GO and rGO180 are added. The spectrum of GO-P25 solution does not show a predominance of the trimer-related peak as GO, but it is more similar to the case of rGO180. Indeed in this case the oxygen availability on GO layer is reduced and this is probably due to the interaction of TiO2 with GO that could enhance the reduction of GO or favour the formation of TiO2-GO aggregates. This effect is less evident in the case of rGO180-P25 solution since the initial graphene oxide is poorer of oxygen moieties.
Antibacterial properties of graphene oxide and reduced (irradiated) graphene oxide
Although disinfection methods currently used in drinking water treatment can effectively control microbial pathogens, research in the past few decades has revealed a dilemma between effective disinfection and the formation of harmful disinfection byproducts (DBPs). Chemical disinfectants commonly used by the water industry such as free chlorine, chloramines and ozone can react with various constituents in natural water to form DBPs, many of which are carcinogens. Therefore, there is an urgent need to reevaluate conventional disinfection methods and to consider innovative approaches that enhance the reliability and robustness of disinfection while avoiding DBP formation. Recently, several natural and engineered nanomaterials have been investigated as possible alternative disinfection methods. Among these materials, carbon-based materials and, in particular, graphene and its derivatives are receiving increasing consideration.
In this work, our idea was to modify the graphene oxide (GO) in a controlled way in order to reduce slightly the amount of oxygen and keep the material still well dispersible in water, since a good dispersibility helps to favour the contact with bacteria eventually present in the water solution. The irradiation of GO was performed by a pulsed visible laser directed in an aqueous solution of GO and the antibacterial activity of GO and GO irradiated at different times (up to 4 hours) was evaluated. In the following we will speak about irradiated GO (iGO), instead of reduced GO, in order to highlight a general modification of GO, instead than a simple decrease of the oxygen concentration. The structural and chemical properties of irradiated graphene oxide (iGO) were studied by UV-Vis optical absorbance, Raman and X-ray photoelectron (XPS) spectroscopies, scanning electron microscopy (SEM) and dynamic light scattering (DLS) technique. The antibacterial activity was tested by using Escherichia coli ATCC25922 as a model organism.
Bacterial survival test and WST-assay (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium) were used. In order to investigate the mechanism of action, the level of lipid peroxidation in the bacterial membrane was tested as well as the integrity of bacterial membrane was observed by scanning electron microscopy images. Moreover, environmental safety of the analyzed compounds was investigated through the Fish Embryo Toxicity (FET) test. FET test is a modern toxicity test representing an effective alternative to acute test with adult fish. In fact, fish embryo-larval assays provide a screening and investigative tool able of testing a larger number of nanoparticles.
In our experimental system, GO irradiated for 3 and 4 hours (iGO3 and iGO4 respectively) displayed the best results as antibacterial materials, as assessed on E. coli, at concentration of 20 mg/l. Such better activity was correlated to the morphology and the size reduction of the irradiated GO flakes that becomes similar to the bacteria size. Moreover, the laser irradiation of GO in water solution preserves the oxygen content at reasonable concentration to make the iGO solutions highly dispersible in water. This effect is essential to have a good interaction between nanomaterials and bacteria in water. Fish Embryo Toxicity test showed that neither mortality nor sublethal effects were caused by the different kinds of GO tested at concentration eight times larger than 20 mg/l. Furthermore, pulsed laser irradiation of GO is an environmental friendly process that avoids the use of chemicals. The efficient photocatalytic rate, the antibacterial properties and the absence of toxicity make iGO a promising green option for possible applications dedicated to water purification.
Nanocomposite polymeric membranes for water purification.
In the last decades the development of efficient and ecologically-friendly methods to remove contaminants from water has become of fundamental importance, since pollution is increasing drastically. Recent advances in nanotechnology suggest that many of the issues involving water quality could be resolved or greatly ameliorated using nanoparticles, nanofiltration or other products resulting from the development of nanotechnology.
Several papers in the literature show the use of TiO2 powder, carbon nanomaterials or a combination of both, dispersed directly in the solution that is going to be treated.
After the photocatalytic process the photocatalyst has to be removed by processes not always easy and fast. Furthermore, the catalyst cannot be easily used again.
A possible solution is to incorporate the photocatalytic nanoparticles in polymeric membranes, that can be removed from water and regenerated for further use after purification processes.
Hybrid nanocomposite Nafion membranes for azo-dye (methyl orange) degradation
We have prepared hybrid Nafion membranes, using various fillers, such as anatase-type TiO2 nanoparticles, graphene oxide (GO) and organo-modified graphene oxide (abbreviated as GOSULF) for water purification applications. Scanning electron microscopy analysis confirmed the homogeneous dispersion of the fillers. The photocatalytic properties of the hybrid membranes were evaluated using the azo dye methyl orange (MO) in aqueous solutions.
The two main effects contributing to the decolourization of the dye, adsorption in the membrane and degradation in solution, were investigated in detail.
MO concentration is reduced by dipping the membranes in solution both in dark conditions and under irradiation, but a stronger effect is observed under irradiation. In particular, the best results are achieved for Nafion–TiO2 and Nafion–GOSULF and they are compared with photocatalytic activity shown by the fillers directly dispersed in MO solution. Nafion–TiO2 under irradiation shows photocatalytic activity for degradation of MO with the formation of by-products, as already reported for TiO2 powder dispersed in MO aqueous solution. The photoactivity of GOSULF has been shown for the first time, but Nafion-GOSULF is more efficient in the dye removal, showing very promising results: after 3 h UVA/blue lamp irradiation a residual MO concentration of less than 30% of the initial value is found, without leaving any other harmful by-products in solution.
This indicates that Nafion can be used as a matrix in which TiO2 and GOSULF can be incorporated, with no photocatalytic efficiency reduction with respect to the same fillers dispersed directly in solution. Among the Nafion membranes under investigation, Nafion–GOSULF, for the first time used for water purification purposes, showed the most promising results in MO adsorption and photocatalytic degradation. We have demonstrated that such membranes may be regenerated and used for several MO removal processes.
Sulfonated graphene oxide nanosheets, as a powder or embedded in polymeric matrix, for cationic dye degradation
Organo-modified GO containing sulfonilic functional groups (GOSULF) was produced by reaction with an acidic amine derivative covalently bonded to the graphite surfaces via nucleophilic substitution reactions on the epoxy groups of GO (see Fig. 1).
GOSULF was then dispersed into an ionomer, such as Nafion® (DuPont), in order to create nanocomposite membranes. Nafion® is a perfluorosulfonic polymer that shows significant properties such as high ionic conductivity, ion-exchange capacity and stable structure, and therefore it is used for various applications such as fuel cells, sensors, and electrochemical devices. The choice of this ionomer for the creation of hybrid films to be tested in water purification applications is substantially linked to two reasons: (1) the acidic properties promote the separation of ionic compounds present in the water and (2) the Nafion membranes have a high capacity to absorb water favouring the effective interaction between contaminants and the active material. The organo-functionalization of the GO surfaces with hydrophilic groups, such as –SO3H, improves both the acidity and the water uptake of the resulting nanocomposite membranes, but also their mechanical, chemical, and thermal strength. Recent results show that GOSULF nanosheets exhibit a better absorption capability in the removal of MB with respect to the GO powder.
We have investigated and compared the degradation ability of GO and GOSULF flakes for removing methylene blue (MB) molecules from water in the dark and under UVA/blue illumination. Furthermore, a specific study on the Nafion–GOSULF composite membrane in the removal of MB was performed and the results compared with the case of methyl orange (MO) removal.
The degradation of MB is larger when GOSULF is directly dispersed in dye solution with respect to the case of GOSULF embedded in the polymeric matrix. MB adsorption by GOSULF occurs immediately and it is larger in comparison with the adsorption capacity of Nafion–GOSULF; it is also known that the adsorption of dyes on the surface of photocatalytic materials is needed in order to achieve dye degradation. Adsorption on GOSULF nanoparticles is favoured with respect to the adsorption on Nafion nanocomposites since in the former case the active sites are immediately accessible to MB molecules, while in the latter case the MB molecules have to diffuse inside the polymeric matrix. Nevertheless, the powder incorporation inside a polymeric matrix gives the advantage to overcome the problems related to the recovery of materials at the end of the process and nanocomposite Nafion membranes can be reused for several purification processes.
Indeed, the possibility of regeneration and reuse of the Nafion–GOSULF composite was also verified in order to demonstrate that the incorporation of nanomaterials inside a polymeric film is a more efficient and ecologically friendly method with respect to the direct dispersion of powders in aqueous solution.
TiO2 Nanowires for water purification
Titanium dioxide or titania (TiO2) is a well-known material that demonstrated optimal photocatalytic proprieties together with various advantageous features, such as long lifetime of excited electrons, nontoxicity, long-term chemical stability, high corrosion resistance and relative low cost.
Its photocatalytic properties are optimal for application in the sector of water purification. Indeed, the photocatalytic reactions generated by TiO2 when exposed to ultraviolet irradiation in the presence of water, decompose organic compounds (e.g. bacteria, pharmaceutical pollutants) decomposing them into carbon dioxide and water. These reactions are a surface based mechanism; therefore, a larger surface area in contact with water will increase the number of the photocatalytic reactions. For this aim, we investigated the synthesis of TiO2 nanowires (NWs) in order to increase the exposed surface area and improve the final photocatalytic efficiency.
TiO2 NWs were synthesized by seed assisted thermal growth on a Ti substrate. This method is widely used with various materials but many of its aspects are not well understood yet.
A Ti foil was coated with a thin film of Au (5 nm) and then processed in a furnace at temperatures between 600-1000 °C for 1 to 4 hours in a mixed gas flow of Ar and O2. The analysis of NWs by scanning electron microscopy obtained in these different ranges of temperature, annealing time, and gas flow, allowed to identify specific optimal conditions for the TiO2 NWs growth in terms of their length, density and uniformity of their areal distribution, and robustness of the sample: 800°C, 4h, 7.5 lpm of O2 and 10 lpm of Ar. The obtained NWs were about 2-3 µm in length and 50-200 nm in diameter with an Au nanoparticle on their top, indicating the mechanism of seed assisted growth.
Structural characterization of the NWs by X-Ray Diffraction revealed a TiO2 rutile crystalline phase with a main peak of the (110) orientation. Transmission electron microscopy indicated that the NWs are pure rutile TiO2 monocrystalline and that their growth direction corresponds to the <110>. An in situ thermal growth (carried out at the University of Oslo) in water vapor atmosphere, showed that the rate of NWs growth in length and density is higher in the first 20-40 minutes and that subsequently the oxidation rate decrease and the NWs tent to shorten and became wider in their base, creating a more wide rods/grains shapes.
The seed assisted growth mechanism occurred by Au forming nanoparticles because of a de-wetting process and catalysing the growth of nanowires; Ti diffused from the substrate up to the Au surface, formed TiO2 by reacting with oxygen and the TiO2 nanowire elongated along a main growth direction. Ti diffusion from the substrate is also indicated by the tapering shape of the NWs, which are characterized by a wide base. Since NWs are not nucleated without gas carrier (in vacuum) we can conclude that the nucleation mechanism cannot be only supported by the surface migration of Ti from the substrate but a certain amount of Ti has to be transported also in the gas phase. This means that the formation of pure Ti NWs is not energetically or kinetically favoured in the full range of explored temperatures (600-1000 °C). Moreover, without catalyst the NWs growth is very difficult to be induced and controlled, only few NWs are observed in small isolated areas of the sample with no reproducibility. To sum up, our experimental results revealed that the seed assisted growth of TiO2 NWs is a very complex synthesis mechanism characterized by an interplay of Ti-Au interdiffusion, Ti migration, gas carrier transport and oxygen gas reaction.
Moreover, we demonstrated that the same method of TiO2 NWs growth can be applied to different type of Ti substrates (Ti foil, Ti thin films, Ti wires), opening new possibilities for different kind of applications.
TiO2 NWs were also modified by doping through ion implantation of Fe+; by tuning the ion implantation energy, NWs showed to change their morphology as a consequence of ion implantation damage by bending like in the case of ion hammering effect reported in literature for Si and Ge nanowires. Further studies of these samples are still on going.
The photocatalytic properties of the TiO2 NWs were assessed by measuring the rate of photocatalytic bleaching of the Methylene Blue dye in aqueous solution via UV spectrophotometry and calculating the photonic efficiency. The sample showed a degradation rate 70% higher compared to the one of a reference TiO2 bulk sample. This is partially due to the measured decrease in reflectivity of the sample in presence of NWs. The photonic efficiency was comparable to the one of the commercial Pilkington-ActiveTM glass, made with TiO2 thin films and applied in many building as self-cleaning glass.
In order to improve the photocatalytic performances of TiO2 NWs, we modified the sample annealing it in forming gas (H2 5% in N2) for 2 hours at 500°C, which was reported to act on the sample defects improving the charge carrier density. The photocatalytic activity of the NWs treated with forming gas, showed to be 3 times higher than that of the reference bulk TiO2 sample (fig.3) while the reflectance was unchanged.
A study of the defects evolution of the NWs was carried out by the very powerful technique of Deep Level Transient Spectroscopy (DLTS) performed at the University of Oslo. First, it allowed identifying in the TiO2 NWs sample, 4 energy levels within the bandgap (at 0.11 eV, 0.30 eV, 0.45 eV and 0.6 eV below the conduction band) never reported before in literature. Second, it revealed that the annealing in forming gas leads to a reduction of deep level recombination centers competing with the photocatalytic processes.
In conclusion, these reported improvements in photocatalytic efficiency indicated the positive contribution of the NW structures, also via the antireflective effect, and the additional positive effect of the forming gas treatment.
Laser synthesis of nanomaterials for water purification
One of the emerging and innovative techniques for water and air purification makes use of photoactive nano-materials. The latter are able to mineralize pollutants and inactivate pathogens bacteria by taking advantage of radical species emission which takes place under materials’ illumination.
A noteworthy application was developed in 2015, namely a “TiO2 based purifying paint” that was used to cover an international airport washroom (at Noi Bai International Airport in Hanoi, Vietnam). However, there is a need for improvement of synthesis techniques of photoactive nano-materials. In fact, among alternative synthesis methodologies for photoactive nano-materials, only a minor part can match the requirements of being industrially compatible, i.e. cheap and scalable, and environment friendly.
Laser irradiation in liquids is a synthesis technology that matches all the above mentioned requirements. For this reason, we focused our attention on its development. In particular, we followed two complementary approaches: synthesis of photoactive nanoparticles in solution and synthesis of a nanostructured surface on a supporting material. These approaches were successfully combined together to realize a highly active device.
Firstly, we synthetized TiO2 nanoparticles in solution by Pulsed Laser Ablation in Liquid (PLAL) which consists of irradiating a titanium foil with a high energy pulsed laser. Particular attention was given to the synthesis and the characterization of the obtained nanoparticles as well as to the analysis of their photocatalytic and antibacterial properties. The synthetized nanoparticles are mainly composed by a mixture of small crystallites and disordered TiO2. Despite their amorphous phase, the nanoparticles showed high photocatalytic and antibacterial activities which are comparable, where not higher, with respect to commercial TiO2 powders, under the same experimental conditions. This unexpected high rate is possibly due to the amount of hydroxyl groups and the presence of the amorphous phase.
The effect of mixing of TiO2 nanoparticles with other nanomaterials was also studied. In order to increase the photoactivity of the TiO2 in the visible range, we synthetized nanocomposites of TiO2 nanoparticles with metals (Ag) or metal oxides (CuO) nanoparticles, both synthetized by PLAL. The nanocomposites gain new interesting properties thanks to a synergic effect of the properties of the respective single materials.
One of the issue of using nanoparticles in solution as a purification system comes from the need of removing the nanoparticles from water after the photocatalytic treatment. In order to solve this issue, another approach can be taken into account: a nanostructured surface can be realized thanks to Laser Irradiation in Liquids (LIL). In fact, we observed that, by irradiating a Ti foil with a high power pulsed laser beam in water environment, a black photocatalytic active coating is formed. We called it “black-TiOx”. The irradiated surface is uniformly covered by cavities of several hundreds nm in diameter with a branched porous nano-structure inside. The latter increases the surface exposed to water, favoring photo-activity. Moreover, photoactivity also benefits from the high absorption in the UV and Visible range. An estimation of the quantum efficiency for UV illumination was obtained by using the approach of the standard ISO10678:2010. We were able to evaluate a quantum efficiency of QEUV=0.011 %.
The photoactivity of this material can be further increased by a factor 4 by using a new approach coming from a combination of the two methodologies previously described, for instance PLAL and LIL. We argued that the relatively low activity (Q.Y.=0.011%) of black-TiOx is related to an inadequate electron transfer to the solution. Thus, an increase of electrons scavenging should bring to an increase of the holes transfer to the solution with a subsequent augmentation of photo-activity. Platinum nanoparticles (PtNps) are well known to favour electrons scavenging thanks to their high affinity with oxygen and their high surface/mass ratio (20 m2/g). On the other side, black-TiOx appears to be metallic and to form an ohmic contact with the underliyng Ti substrate. We prepared PtNps by PLAL and subsequently we positioned these nanoparticles on the rear side of the Ti target. We than irradiated the target to realise the black-TiOx by LIL. The backside position of PtNps allowed us to avoid the formation of a Shottky barrier between TiOx and Pt which would have reduced the efficiency of electrons scavenging. Moreover, this allowed us to avoid the shielding effect of light by Pt nanoparticles. In the end, the deposition of PtNps on the rear side of the black-TiOx sample creates a sandwiched structure called “photochemical diode” with an increased photocatalytic activity. The quantum efficiency displayed by this “photochemical diode” is Q.Y.UV=0.058 %, that is more than twice of what is observed for commercial glasses.
In conclusion, we developed two environment friendly methodologies to synthetize photoactive materials, namely PLAL and LIL. Combining these two methodologies, we were able to manufacture a new and interesting device with a high quantum efficiency that could be used for water purification.
The biological side of the story.
a) Characterization of antibacterial properties of TiO2 and carbon-based nanomaterials.
According to UN regulations, access to clean drinking water is a human right. However, the number of people living in areas without safe drinking water is predicted to heavily increase by the end of this decade. On the other side, disinfection methods currently used in drinking water treatment, as water chlorination, may bring to the formation of harmful disinfection byproducts (DBPs). Alternative disinfection processes including ozonation, advanced filtration processes and germicidal ultraviolet (UV) radiation require expensive chemicals or costly equipment. Thus, there is a need to develop new efficient, low cost and safe methods of purifying water. In the last years, several nanomaterials have been investigated for their possible role in alternative disinfection methods.
Since the first observation of antimicrobial activity of TiO2 made by Matsunaga in 1985, many studies have investigated the disinfection potential of photocatalysis using TiO2 as photocatalysts. According to literature data, highly reactive oxygen species (ROS) are thought to be the key species in the photocatalytic disinfection process, with the hydroxyl radical being the most important oxidant species responsible for the attack of the bacterial cell wall, leading to modifications of membrane permeability and cell death.
All the TiO2 based nanomaterials realized during the WATER project were tested for their antibacterial activity. The Escherichia coli ATCC25922 strain was chosen as a model organism. It has been recently suggested that, for a number of reasons, E. coli appears to provide the best bacterial indication of fecal contamination in drinking water, replacing total coliforms. In addition, the ATCC25922 strain was not genetically modified for molecular biology purposes, hence possible resistance mechanisms were not weakened. Antibacterial activity was evaluated through CFU counts, as a first screening. Wherever interesting results were obtained, bacterial metabolism and possible mechanisms of action were further investigated.
The experiments performed in these years suggested that there is a positive correlation between the extension of nanomaterials surface and the antibacterial activity. Metabolism rate, as measured by MTT Assay, was decreased in parallel: the more active the material, the more lowered the metabolism. The analysis of the mechanism of action suggested that bacterial membrane oxidation takes place in presence of TiO2. Membrane lipid peroxidation level was assessed through measurements of the level of malondialdehyde (MDA), made by the ThioBarbituric Acid Reactive Substances (TBARS) Assay. Exposure of bacteria to laser ablated TiO2 nanoparticles generates a statically significant higher level of MDA, as an example. Moreover, some structures, as nanotubes and nanospikes, display some antibacterial activity even in the absence of UV direct illumination, indicating that some percentage of the antibacterial activity may be due to possible mechanical damage.
Besides TiO2 nanomaterials, carbon-based materials and, in particular, graphene and its derivatives are receiving increasing consideration as they offer the promise to improve existing products and to enable the design of materials and devices with novel functionalities. In our laboratory, graphene oxide (GO) and laser irradiated graphene oxide (iGO) were tested. Best results were obtained with 3 and 4 hours laser irradiation. iGO3 and iGO4 displayed good antibacterial activity and a correspondent decrease in metabolism rate. Analysis of the mechanism of action excluded membrane damage through oxidation. SEM analysis of bacteria, after iGO3 and iGO4 exposure, suggested that mechanical damage is main responsible for the displayed antibacterial activity.
b) Metagenomics: paving the way for marine microbial ecosystem analysis.
The WATER project reads: “Aci Castello, a small town in the Catania area with a protected sea region of EC interest, has been selected as a pilot case to study the effect of nanotechnology applications for water treatment systems. The costal sea is affected during the summer by a contamination with Ostreopsis algae, whose level is definitively higher than normal during the peak of tourism.” [WATER-Grant number 316082- page 8]. The WATER Strategic Research Domain (SRD) task 3 focused on this pilot case. One of the aims of the SRD task 3 was to analyze the state of the sea water in Aci Castello in order to acquire the necessary information about the biological and ecological state of the water. With this goal in mind, a metagenomic study has been performed to evaluate marine microbial communities. Metagenomic approaches based on direct isolation of nucleic acids from environmental samples have proven to be powerful tools for comparing and for exploring the ecology and metabolic profiling of complex environmental microbial communities (Simon C. & Daniel R., 2011).
In the last decade a number of studies demonstrated species–area relationships, biogeography, and spatial patterns at various scales for microbes. Next to this, microbial endemism has been reported as well. (Bodelier, 2011). However, microorganisms change over multiple timescales and in response to different forces, including both biological and non-biological properties of the environment that drive changes in microbial community composition. A great deal can be learned by evaluating the dynamics of community composition and the corresponding environmental parameters (Furhman, 2015).
In our study, thanks to the collaboration with the WATER partner Area Marina Protetta Isole Ciclopi, two sampling sites were selected (Eulerian sampling). One of the sites is close to the sewer (COL sample), while the other is 300mt away from the first, offshore, in an area fully pertaining to the marine protected area (PAN sample). Both the 16S and 18S genes were analyzed in parallel so to get a comprehensive view on both bacterial and microalgae communities. The underlying idea was to understand whether in summer time the anthropogenic pressure may affect communities composition. Thus, two sampling campaigns were performed, at the end of winter time and at the end of summer time. The overall composition of microbial communities shows that the Proteobacteria Phylum was the most abundant, followed by Bacteroidetes. Within the Proteobacteria Phylum, the classes Alpha-, Epsilon- and Gammaproteobacteria were the three most represented. The study revealed that the difference in the communities composition is mainly related to the site of sampling. In fact, the core microbiome was deeply different between sites. The top ten OTUs of each station were exclusive. In the COL sample community, close to the sewer, the most abundant OUT belongs to the Cryomorphaceae family (Class Flavobacteriia, Phylum Bacteroidetes) followed by by the genus Arcobacter (Class Epsilonproteobacteria) and the family Rhodobacteraceae (Class Alphaproteobacteria). The PAN sample community display the typical structure of a marine community comprising Pelagibacteraceae, (Phylum Proteobacteria, Class Alphaproteobacteria) and the Cyanobacteria Phylum. Furthermore, seasonality affects the core structure of the microbiome. Of interest, there is a significant increase in the Bacteroidetes Phylum, especially in the COL sample.
Potential Impact:
The overall impact of the WATER actions can be essentially described in terms of internal and external consequences of our improved research potential:
• The main internal impact is related to the strategic reorganization of our research plan, both in terms of human and technical reinforcement, that will deeply affects the management of available resources. Better exploitation of research facilities, top class participation to H2020 and above all a renewal of an outdated research management with the definitive assessment of a younger and innovative approach to research and social role of scientists. The innovation dimension of this restructuring will go beyond the WATER action, as the reinforcement of human capabilities of strategic vision will be the key issue to start up a more efficient exploitation of our capitalized research resources. This internal impact has not been yet fully achieved, for the resistance of an old mentality of the work environment still anchored to an outdated approach to the research. WATER is trying to affirm a new way of thinking the research, where dissemination can be as important as the scientific publication, or learning the correct methodologies of people management can be an effective expense as that of a new equipment. WATER has shown a balanced approach to all of these issues, but we still need some time to make some part of the work environment understand that such balance is getting closer to Europe than other approaches only based to the scientific competition.
All of these matters were deeply discussed with the independent experts nominated by the EC for the final evaluation, trying to draw a roadmap to put in practice these objectives that is summarized in their evaluation report.
Another positive consequence coming from this action is relative to the capability of attracting external funds. The visibility gained by WATER in fact produced as a result that many potential partners (other CNR Institutes, University of Palermo, University of Catania, some companies) contacted us for future European and national programs, looking at WATER as a reference for the activity on water treatment by nanotechnology. Furthermore, based on the experience we gained, both relative to the submission of the proposal and its evaluation, and to the management of the action, our attitude to the preparation of new proposals is wiser. I can notice the different approach of the WATER team and of other colleagues with respect to drawing a European project, the former being aware of the scheme to follow and of the essential data a proposal has to contain, the latter being more oriented to the scientific matters without taking into the right account also the impact aspects and how they have to be measured. The self evaluation skills improved through the WATER story, probably also thanks to the experience of the coordinator as H2020 evaluator, are resulting crucial in planning new project activities. Of course we are spreading such a more refined approach to writing new proposals also to the external colleagues, so extending the gained know how to the local scientific community, trying to take the best global profit from the WATER experience.
• The external impact can be distinguished in European added value and local added value. From the EU point of view the exploitation of research facilities at EU level and the realignment of research efforts on topics of ERA interest represent the fundamental values to return from the relevant EU investments that have been distributed in Sicily. The enlargement of the capacities for the nano-structure synthesis will significantly improve the scientific and technical infrastructure for this kind of research. Even more than that, potential users of the upgraded facility might be not only the participants of this Action, but also national and international materials science research groups, contributing to a shared increase of the quality of research. CNR Catania will hence become a reference, excellence centre for this kind of synthesis of nanostructures, certainly on a national, but also European level, thanks to the resonance of this action. This is already occurring, with the case of some colleagues from CNRS France asking for making some common experiments by using our ALD system for depositing Ag and Pt on nanostructures synthesized in their Institute to be applied to Atomic Force Microscopy. Furthermore, our affirmation in the field of nanotechnology caused that a member of our CNR Unit has been appointed as the head of the research area “Functional nanomaterials” in the recent reorganization of the entire CNR Institute. Specifically, we have supported for this position a colleague not directly involved in WATER, because we want to extend the impact of the action as broad as possible, without restricting the positive return to a group of “privileged” people.
The public and private local initiatives suffer of a lack of organization that has been supported by the WATER actions about its specific domains. Moreover, the strong action of WATER dissemination specifically addressed to cover the gap between science and society will have a long term impact by creating a general thrust into scientific resources to drive the economical development of a country. The local impact of the WATER dissemination actions is contributing to build a new image of science in today’s life and to improve the visibility of local scientific research centers. Local authorities and SMEs looked at WATER ideas with growing enthusiasm and positive participation that can spread around and inflame a renascent general mobilization. It is remarkable that a worldwide leader in water filtration system, ATLAS Filtri, decided to support WATER with the perspective to implement new research initiatives, and that local SME (Fonte Nuova, Plastica Alfa) have signed a MoU with CNR for exchanging ideas and put in practice a technological transfer. . We want to pursue a stronger cooperation between academia and business via staff exchange, that might turn creative ideas into innovative products and processes to address European and global societal challenges.
The action wants to strengthen research and business performances and promote innovation and knowledge transfer throughout the EC support. Stronger cooperation between universities and business via staff exchange will encourage entrepreneurship and help to turn creative ideas into innovative products and processes that can efficiently address European and global societal challenges.
In general, we can claim that the research strategy decided when the proposal was drawn up, i.e. the reinforcement of our skills in the area of nanotechnology, for innovative applications to the mammoth problem of water for the humanity, had an impact in terms of i) scientific production, ii) visibility both to the professionals and the broad public, iii) cultural growth of the team, iv) relationship with SME.
Concerning the projection of our initiative to a broader field of applications, WATER represents a bridge – for the first time in a European high tech context – between local authorities, SMEs (New Ecotecnica Sud, etc.) and world leader industry in the filters technology (ATLAS Filtri). All of these interactions, and the consequent achievements we expect, would not exist without the human and technical reinforcement guaranteed by this action.
We made a significant effort to stimulate a two-way dialogue with the general public that will influence decisions concerning scientific and environmental policies and will be crucial for long-term development of nanotechnology in Catania. The dissemination initiatives we propose are definitively innovative for our scientific environment, also at European level, and aim to a general cultural growth.
In general, we can claim that the research strategy decided when the proposal was drawn up, i.e. the reinforcement of our skills in the area of nanotechnology for innovative applications to the mammoth problem of water for the humanity, had an impact in terms of i) scientific production (28 JCR publications), ii) visibility both to the professionals and the broad public (20 presentations at international conferences, 4 awards, independent mentions on the media) iii) cultural growth of the team (attendance to top level courses on management and communication), iv) relationship with SME (two MoU signed, two companies among the partners).
In 2004 the European Commission published its strategy for Nanotechnology, one of five key dynamics identified is the need to “integrate the societal dimension”. It argues that ethical principles must be respected and that public dialogue can be an important contributor to developing socially beneficial nanotechnologies. Without a serious communication effort, nanotechnology innovations could face an unjust negative public reception. An effective two-way dialogue is indispensable, whereby the general publics’ views are taken into account and may be seen to influence decisions concerning R&D policy. The public trust and acceptance of nanotechnology will be crucial for its long-term development and allow us to profit from its potential benefits. It is evident that the scientific community will have to improve its communication skills.[Communication from the Commission – Towards a European strategy for nanotechnology, 2004]. With this aim, communication skills were potentiated as complementary skills for researchers with special trainings (WP2) and particular attention was paid in the formulation of messages to be disseminated (WP 4). The only way to avoid useless waste of resources (money and personnel time) is starting to operate with technicians of communication. In this sense, this approach is new for this community and it represents a fundamental innovation of the WATER action in our local professional environment. This new approach about transversal visibility produced its results: from the professional point of view we recruited PhD and Master students from other Scientific areas (biology, chemistry), but also the potentiality of new media channels, like Facebook, has been exploited with the result of a large public renovated interest in local science events.
Local authorities and SMEs have been attracted by our broad range promotion events looking at the immediate advantages of self publicity, with a consequent interest in science and in the CNR activities. Through focused activities of WP2 about the research domain addressed by WATER, the local authorities and SMEs were involved in research tasks. This realized a missed link among CNR and local stakeholders.
WATER applied for the organization of the IEEE (Institute of Electrical and Electronics Engineers) NMDC (Nanotechnology Materials and Devices Conference) on May 2013. On October 2013 the President of the IEEE Nanotechnology Council, Prof. Stephen Goodnick, committed the organization of the IEEE-NMDC 2014 to the CNR-Catania.
The IEEE-NMDC 2014 (http://www.ieee-nmdc2014.org/) was the 9th edition in an international series. It was hosted for the first time in Europe, Sicily, Aci Castello (Italy), in Grand Hotel Baia Verde (http://www.baiaverde.it/EN/) on October 12-15, 2014.
The conference was a forum of discussion about nanotechnology, with a special focus on materials and devices. The main objective of the conference was to gather leading edge scientists in the field of nanotechnology to review the most recent highlights, spread over several applications area.
The scientific program included plenary sessions (one a day), two parallel oral sessions, a poster session and an exhibition of the sponsors (the WATER project was the premier sponsor of the conference). In detail, the conference had 3 plenary speakers, 15 invited speakers, 73 oral presentations, 50 poster presentations, 10 sponsors. Moreover, three oral sessions and one session of the posters were focused on “Nanostructures for water purification”, that is the subject of the WATER project. All the presentations were high-level presentations, followed by constructive and lively debates. The poster session was made up of high-level posters with a lot of scientific debates.The three best oral presentations by young scientists and the three best posters were awarded during the closing session.
During the conference an event dedicated to Ph.D. students and young scientists was organized: “Lunch with Prof”. Young scientists had the opportunity to have the lunch (one a day) with the plenary speakers: sitting around a table, enjoying the Italian cuisine, the students shared with outstanding scientists ideas, curiosities and experiences.
Scientists from research centers, universities and industries, from all over the world (30 different countries), attended the conference. In total the number of participants was 207.
A video of the congress has been commissioned to an advertising agency, so to give visibility to the CNR-Catania and to the WATER project.
“Congratulations on a very nice conference, the attendance was better than expected, the scientific and social programs were very well organized, congratulations on a very successful conference” wrote Prof. Stephen Goodnick, Past President of the IEEE Nanotechnology Council.
On January 2014, a proposal was submitted for the organization of a symposium at the 2015 E-MRS (European-Materials Research Society) Spring Meeting as principal organizer. The E-MRS Spring Meeting is the largest material forum in Europe. The proposed symposium was entitled: “Materials for applications in water treatment and water splitting”.
On April 2014, the symposium was accepted as symposium B of the 2015 E-MRS Spring Meeting (http://www.emrs-strasbourg.com/index.php?option=com_content&task=view&id=800&Itemid=1652). The meeting was held at the Congress Center (Grand Palais) in Lille (France), on May 11-15, 2015. The congress included 32 parallel symposia, one plenary session and one exhibition session, with more than 3000 attendees.
The symposium B was focused on materials science, processes and device issues for future efficient water applications, with the main aim of attracting, for the first time at the E-MRS meeting, experienced researchers in the field of advanced materials for water purification and hydrogen production by water splitting, so to encourage the cohesion of these communities.
The symposium was sponsored by the project WATER and by ATLAS Filtri company, partner of WATER.
The symposium received 165 abstract, and since the abstract exceeded 100 it was considered a large symposium.
Scientists from research centers and universities, from all over the world (36 different countries), attended the symposium B.
In detail, the symposium had 12 invited speakers, 68 oral presentations, and 72 poster presentations.
The symposium had 12 oral sessions and 2 poster sessions. All the presentations were high-level presentations, followed by constructive and lively debates. The poster session was made up of high-level posters with a lot of scientific debates.
The 2 Graduate Student Award winners of the symposium, selected by a commission formed by the symposium organizers and two members of the scientific committee, were honored during the plenary session by the E-MRS. In addition, thanks to the support of the sponsors (WATER and ATLAS Filtri), 6 best posters were awarded during the closing session of the symposium.
The proceedings will be published by the Elsevier in a special issue of “Materials Science in Semiconductor and Processing” next December.
An advertising campaign has been developed to inform the general public about the WATER action. We communicated with the society by means of advertisements on: newspapers and magazines (both printed and on-line), radio, and TV. The advertisement campaign has been designed thanks to the support of an advertising agency (Boomerang adv, www.boomerangadv.com).
The commercial is available through the WATER web-site (www.water.imm.cnr.it) on the home page.
The slogan is always the same: “So that our children will not be in bad water”.
The advertisement appeared on broad-audience newspapers. In the following is listed the newspapers and the days of publications:
La Repubblica (March 22nd, 2014; March 28th, 2015)
Il Sole 24 Ore (March 21st, 2014; March 27th, 2015)
La Repubblica Regional (Sicilian) Edition (March 18th, 2014; March 24th, 2015)
Il Sole 24 Ore Web (March from 17th to 23rd, 2014; March from 23rd to 29th, 2015)
The advertisement appeared on broad-audience magazines. In the following is listed the magazines and the days of publications:
L’Espresso (weekly) (May 30th, 2014; June 15th, 2015)
Focus (monthly) (June, 2014; June, 2015)
The radio advertisement went on the air on national networks as reported below:
Radio 1, Radio 2, and Radio 3 (from January19th to 26th, 2014 for a total of 21 passages)
Radio 1, Radio 2, and Radio 3 (from January25th to 31st, 2015 for a total of 21 passages)
A commercial went on national and satellite TV as reported below:
TGCOM 24, Iris, Rete 4, Canale 5 (from December 15th to 29th, 2013, for a total of 49 appearances)
Sky, National Geographic (from September 21st to 28th, 2014 for a total of 70 appearances)
Sky, Discovery Channel, Discovery Science (from July 6th to 12th, 2015 for a total of 138 appearences)
A clear consequence of the advertising campaign was a lot of independent articles, both printed and no-line, focused on the WATER action (for major information click on:
http://www.water.imm.cnr.it/index.php?option=com_content&view=article&id=85&Itemid=451&lang=en
http://www.water.imm.cnr.it/index.php?option=com_content&view=article&id=86&Itemid=460&lang=en). These significantly increased the visibility of the CNR-Catania at regional and national level.
The CNR group participated during the WATER action to several conferences in order to disseminate its scientific results. Some examples relative are reported in the following.
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: Annual International Eurodoc Conference Place: Budapest, Hungary
Location: Budapest, Hungary
Date: March 25-29, 2014
Type of presentation: Invited talk
The conference titled: “The position of Early Stage Researchers in ERA & EHEA. How to face the challenges ahead?” More than 100 participants from all across Europe gathered in Budapest, Hungary, to discuss the challenges that Early Stage Researchers (ESRs) face in the European Research Area (ERA) and in the European Higher Education Area (EHEA). One of the most relevant topics discussed during the three days of this event was the professional development that doctoral candidates and Post-Doctoral researchers need in a challenging scientific environment.
Maria Antonietta Buccheri took part to the conference as an invited speaker for the Plenary session I: “Where we stand- the position of ESRs in ERA.”. She reported Marie Curie Fellows’ views and experiences on the subject, both acknowledging progresses made in recent years and addressing key issues to be afforded in order to make researchers’ careers in Europe more attractive.
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: Euroscience Open Forum 2014 (ESOF2014).
Location: Copenhagen, Denmark
Date: January 20-26, 2014
Type of presentation: Organization of a session
Maria Antonietta Buccheri organized a session in the frame of the “Career programme” dedicated to researchers careers: “Researchers’ careers in Europe: looking for the Ariadne thread in the MCFA world café”.
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: LET’S 2014
Location: Bologna, Italy
Date: September 29 - October 1, 2014
Type of presentation: Poster presentation, B2B meetings
“Facing WATER challenges through nanotechnologies.”
LET’S 2014 (Leading Enabling Technologies for Societal challenges) is an international Conference organized in the context of the Italian Presidency of the Council of the European Union, with the Patronage of the Ministry of Education, University and Research, the Ministry of Economic Development and the Ministry of Foreign Affairs, and supported by European Union Funding for Research and Innovation.
During the conference, the poster presented by Maria Antonietta Buccheri attracted some interest and she was interviewed by TRIWU’, a web tv dedicated to innovation and transfer of knowledge. Interview can be found at the following link: http://www.triwu.it/categorie/-/asset_publisher/Fm8O/content/filtri-nanotecnologici-per-la-depurazione-dell%E2%80%99acqua?p_r_p_564233524_categoryId=10679
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: 101st International VLB October Convention
Location: Berlin, Germany
Date: September 28-29, 2014
Type of presentation: Invited talk
“Applications of nanotechnology to water treatment: the European project WATER”
The Research Institute for Water and Waste Water Technology (FIWAT) at the Versuchs- und Lehranstalt für Braurei in Berlin (VLB) is one of the partners of the WATER project. Fruitful links have been developed with the Institute. The opening session was focused on “Nano and micro particles in complex liquids”. Maria Antonietta Buccheri was invited to take part to the session, where she highlighted the WATER project and shed light on possible applications of nanotechnologies to water treatment.
• Person: Ruy Gonzalez and Giuliana Impellizzeri, CNR Researchers
Event: Visit and Beam time at the Centre for Micro Analysis of Materials (CMAM) of the Universidad Autónoma de Madrid
Location: Madrid, Spain
Date: February 13-19, 2014
Type of presentation: Seminar
“Ion Beam modified TiO2 for advanced water purification in the frame of WATER project”
• Person: Vittorio Privitera, CNR Senior Resercher
Event: Ettore Majorana Foundation and Centre for Scientific Culture, ERICE. International School "Materials for Renewable Energy" 2014. Chaired by David Cahen (Weizmann Institute of Science, Rehovot, Israel), David Ginley (NREL, Golden, Colorado USA), John Poate (Colorado School of Mines, Golden, Colorado USA), Abdelilah Slaoui (InESS-CNRS, Strasbourg, France), Antonio Terrasi (Dept.of Phys. and Astr., University of Catania, Catania, Italy)
Location: Erice, Italy
Date: July 12-18, 2014
Type of presentation: Lecture
Presentation of the European Project “Water”
• Person: Lucia Romano, Researcher at the University
Event: ICONN 2014 (International Conference on Nanoscale and Nanotechnology) and ACMM23 (23rd Australian Conference on Microscopy and Microanalysis)
Location: Adelaide, Australia
Date: February 2-6, 2014
Type of presentation: Invited talk
“Semiconductor metal oxides nanostructures for water applications”.
• Person: Lucia Romano, Researcher at the University
Event: E-MRS Spring Meeting 2014 (http://www.european-mrs.com/)
Symposium E: Defect-induced effects in nanomaterials
Location: Lille, France
Date: May 25-30, 2014
Type of presentation: Oral and poster presentations
1) Oral presentation
“Swift heavy ion beam modification of rutile TiO2 for photo-catalysis applications”
2) Poster presentation
“Fe-ion implantation induced defects in TiO2 thin films”
3) Speech, during the Plenary Session, focused on the description of the activity “Nanergame”, developed in the framework of the WATER project, that received the “Reach.Out!” competition award
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: Workshop “Researchers’ careers: does Theseus need a new thread across the labyrinth?” Organised by the Marie Curie Fellows Association (MCFA)
Location: London, UK
Date: February 28 - March 1, 2015
Type of presentation: Workshop Co-organiser & Speaker.
• Person: Giuliana Impellizzeri, CNR Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Location: Lille, France
Date: May 11-15, 2015
Type of presentation: Opening of Symposium B (as the Principal Organizer of the Symposium)
• Person: Giuliana Impellizzeri, CNR Researcher
Event: Energy Materials Nanotechnology (EMN) Cancun Meeting 2015
Location: Cancun, Mexico
Date: June 8-11, 2015
Type of presentation: Invited talk
“TiO2 nanomaterials: synthesis, properties, modifications, and photocatalytic applications”
• Person: Vittorio Privitera, CNR Senior Researcher
Event: Campus Colloquia Series
Location: Bologna, Italy
Date: April 22, 2015
Type of presentation: Invited lecture
“Nanotechnology for water purification: the European project WATER”
• Person: Vittorio Privitera, CNR Senior Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Location: Lille, France
Date: May 10-15, 2015
He was a Member of the International Scientific Committee of Symposium B; Chair of Poster Session I - Materials for Environment; a Member of the Commission for the Best Student Award.
He was co-author of 10 oral and poster presentations.
• Person: Vittorio Privitera, CNR Senior Researcher
Event: MiNaB-ICT – International Workshop on “Micro-Nano-Bio-ICT Convergence”, Current Research and Future Trends (http://minabict.fbk.eu/)
Location: Otranto (Lecce), Italy
Date: July 13-15, 2015
Type of presentation: Invited talk
“TiO2 and C-based photocatalytic nanomaterials for water purification”
• Person: Vittorio Privitera, CNR Senior Researcher
Event: Italian National Conference on Condensed Matter Physics (FISMAT 2015)
Location: Palermo, Italy
Date: September 28 – October 2, 2015
Type of presentation: Invited talk
“TiO2 based photocatalytic nanomaterials for water purification”
• Person: Lucia Romano, Research at the University
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Place: Lille, France
Date: May 10-15, 2015
She was a Member of the International Scientific Committee of Symposium B; Chair-person of the Session “TiO2 for water splitting I” of Symposium B; Member of the Poster awards committee of Symposium B.
She was co-author of the following presentations:
• Person: Ruy Sanz Gonzales, CNR Researcher
Event: MRS Spring Meeting 2015
Location: San Francisco, USA
Date: April 6-10, 2015
Type of presentation: Oral and poster presentations
Oral presentation to Symposium UU
“Antireflective Rutile TiO2 Nanospikes Showing Enhanced Photo-Activity”
• Person: Ruy Sanz Gonzales, CNR Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Location: Lille, France
Date: May 11-15, 2015
Type of presentation: Oral and poster presentation
1) Oral presentation to Symposium W
“Response of aortic vascular smooth muscle cells, human mesenchymal stem cells and E-coli to rutile TiO2 flat and nanospikes surfaces”
2) Poster presentation to Symposium B
“Photoactivity of TiO2 and Au decorated TiO2 nanotubes for application in water purification”
• Person: Ruy Sanz Gonzales, CNR Researcher
Event: Visit to the Instituto de Microelectrónica de Madrid
Location: Madrid, Spain
Date: September 30, 2015
Type of presentation: Seminar
“TiO2 nanostructures in the frame of WATER Project“
• Person: Viviana Scuderi, CNR Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Location: Lille, France
Date: May 11-15, 2015
Type of presentation: Oral presentation
“TiO2 nanoplumes for efficient photocatalysis under UV-VIS light”
• Person: Massimo Zimbone, CNR Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Location: Lille, France
Date: May 11-14, 2015
Type of presentation: Oral presentation
“Effect of calcination temperature on the photo-catalytic and antibacterial activity of TiO2 nanoparticles obtained by pulsed laser ablation in liquids”
WATER organized and participated to roundtables, B2B meetings and events with SMEs and industries in order to increase the interaction between the CNR group and the industrial world. The dialogue was established not only with companies supporting the WATER action (i.e. Atlas Filtri and New Ecotecnica Sud), but also with other national and international companies. These interactions can be helpful for the sustainability of the present action beyond its lifetime.
Europe 2020 strategy for growth, reaching the southern Italy market and its key players.
B2B Networking event – Business, Technological and Research Partnership in Sicily and Italy.
https://www.b2match.eu/m4g-italy-sicily
Location: Palermo, Italy
Date: March 27-28, 2014
The aim of this event was to promote business, technological and research partnerships between Italian, especially Sicilian, and European/non-European companies, universities, research centers, technological institutes in active sectors identified as key contributors to achieving growth in southern Italy.
The event was organized with the support of the Enterprise Europe Network and Regione Sicilia.
This B2B event aimed to initiate R&D, technological and commercial cooperation in the following sectors: agro food; bio-agro food; maritime industry and fishing; intelligent energy; tourism and cultural heritage; handicrafts; textiles, clothing and fashion; biotechnology & biomedical; ICTs; construction & green building; creative industry; others. Moreover, face to face meetings between European and Italian companies gave the opportunity of: targeting potential business partners; reaching the Italian market and its key players; examining business and investment opportunities in Sicily; establishing cross-border contacts and partnership; exploring opportunities of research cooperation also in the framework of Horizon 2020 programme.
Meetings with Plastica Alfa
Location: Caltagirone (Catania), Italy
Date: May 6, 2015
A roundtable was held at the headquarter of Plastica Alfa (http://www.plasticalfa.com/index.php/en/) a Sicilian SME also experienced in water filtration systems. The CNR group visited the production site.
In order to formalize the collaboration between the project WATER and Plastica Alfa a Memorandum of Understanding was signed.
Locations: Catania, Italy
Date: May 27, 2015
A second meeting with Plastica Alfa was organized at the CNR Unit at the Department of Physics in order to discuss about future scientific interactions and funding possibilities. During the meeting the WATER team gave the following presentations:
- Efficient photocatalysis polymeric nanocomposites for water purification, Maria Cantarella
- Membrane technology for water purification, Simona Filice
- Carbon nanotube- and graphene-based materials for water purification, Daniele D’Angelo
The members of Plastica Alfa also visited the laboratories of the CNR group.
In terms of exploitation of the project results, a MoU was signed with Plastica Alfa as a result of our meetings and we are agreeing on the signature of a research contract for CNR.
In general, the WATER action aimed to boost the scientific and technological research potential of CNR in the emerging research area of water treatment. New specific research lines about nanotechnology applications for water treatment were opened, thanks to the strong background of the CNR researchers in materials science and nanotechnology, thanks to the upgrading of the existing facilities with new research infrastructures, and thanks to the strong collaboration with the partners of the WATER project. Two main research lines were established. The first one is based on metallic oxide nanostructures for water treatment. TiO2, ZnO and CuxO nanostructures show relevant properties of photocatalytic degradation of water pollutants. Several forms of nanostructures (thin films, nanoparticles, nanowires, nanotubes, etc.), possibly coupled with metals, are synthesized with the main aim of improving the efficiency of the materials in water disinfection and purification. The second research line is focused on carbon-based materials for water treatment. Carbon-based materials can be fruitfully applied for water treatment. Carbon nanotubes, acting as nanoporous adsorbents, work effectively against chemical and biological contaminants. They can be also used to enhance the photocatalytic properties of TiO2 nanostructures. Graphene and graphene oxide have also a great potential for water filtration.
The conclusive event of the project celebrated science and water in the Castello Square in Aci Castello, on October 3rd, 2015, just at the beginning of the last evaluation semester. The festival was called “Water Day”.
The main aim of this action was to attract SMEs, industries, research organizations, but also the general public, policy makers, and Media towards the topics of WATER. For this reason, the Water Day was publicized through an intense advertising campaign. The advertisement campaign was designed and planned thanks to the support of our advertising agency (Boomerang adv, www.boomerangadv.com) in a coherent style with the WATER campaign on newspapers and magazines (both printed and on-line), radio, and TV, developed during the last three years (from 2013 to 2015). We put up 210 billboards, for two weeks, in Catania, Aci Castello, Aci Trezza, Acireale, and Etna villages.
An advertisement also appeared in the most widespread newspaper in Sicily “La Sicilia” for two days. We promoted the Water Day through the social channels (facebook and twitter) and the web-site of the WATER project. Finally, we advertize the event in several SMEs and in primary and secondary schools in the Ionian coast of Sicily.
Six exhibitors participated to the event: the project WATER (with a stand showing posters and nanostructured materials synthesized during the last three years), the Municipality of Aci Castello that also patronized the event, the Marine Protected Area of the Cyclops Islands, Atlas Filtri, New Ecotecnica Sud, and Fonte Nuova (local company experienced in the distribution of filtered and purified water, that signed a memorandum of understanding with the WATER consortium). The project WATER also organized a stand for kids with experiments, games, and gifts. A catering and many gadgets gladdened the local community. In the following the program of the event is reported.
The Norman Castle of Aci Castello simultaneously hosted a meeting focused on the “Future of water resources in the Mediterranean countries”, with the participation of the Mayor and the Heritage Councellor of Aci Castello and the Spanish governor of the region of Almeria. This institutional event was the occasion to spread the results of the project WATER and promote the visibility of the CNR-Catania at European level. In particular, the region of Almeria has a pilot plant for the decontamination and disinfection of water by solar photocatalysis (mechanism that has been extensively studied by the WATER consortium during these three last years). In the following the program of the institutional event is reported.
More than one thousand people attended the Water Day, well beyond our expectation. The event was also attended by the European partners of the project, from France, Germany, Norway and Spain, and by the Members of the Advisory Board, from USA and Australia.
The Water Day strongly attracted the Media, as demonstrated by the presence of several local TV channels and by articles published in on-line journals and also in “La Sicilia” newspaper (on October 4th, 2015).
A video of the event has been commissioned to our advertising agency, so to give visibility to the CNR-Catania and to the WATER project.
The Water Day was an important occasion for the CNR group to strength its link with the general public, policy makers, Media, SMEs and other research organizations.
The overall actions in terms of dissemination strategy and human resources valorization represented indeed the development of the exploitation plan of WATER. Our target was to establish industrial and commercial links, so contributing to the economic development of our region. Some SMEs and companies, supported by signing MOU documents, are taking advantages of the WATER research, within the framework of our IP and research strategy. We organized and participated to many events and workshops addressed to enterprises with the aim to stimulate the interest of industries converting our research results into saleable products, so to reach the goal to commercialize our research findings. The involvement of local authorities contributed to address the research outcomes towards the care for the environment by producing in a long term vision direct benefits on the tourism and a better exploitation of local resources. The achievement of a high capability of research management and of strategic vision is a fundamental result for the economic and social outcomes of our research potential. The latter was exploited through a human and technical reinforcement path, bringing to a more significant involvement in the European collaborative research and in a more productive activity of the applicant, that attracted bright researchers and improved the research network at national and international level. Instead, the top management capabilities were the key to change the mentality of the research group, from a daily problem solving approach to a methodology of long term vision and strategy. Furthermore – based on the knowledge acquired thanks to the exchanges, the courses, the seminars, the contacts with the local authorities and SME, the external evaluation – the action produced the establishment of practices and procedures for capacity building, quality improving and highly specialized training. We exploited such “protocols” by sharing them with the local scientific entities and putting our competence in these fields at the service of our Institute.
List of Websites:
www.water.imm.cnr.it
The overall objectives of WATER were: strengthening the research potential in order to formulate a solid and long term research strategy about nanotechnology applications; increasing our visibility in the ERA; determining an impact on the local economy and society through technology innovation. The focus was on the application of nanotechnology to water treatment, aiming to boost the research potential in this emerging research domain.
Worldwide 1.2 billion people suffer inadequate access to clean water. Nanotechnology is expected to improve the water filtration with lower cost and energy. These were the major motivations for undertaking such an initiative – relying on the local know-how on nanotechnology – aiming to develop novel applications attracting industrial and service assets.
The action included widening of the existing research infrastructures; exchange of know-how and personnel with partners to tackle the issues of the proposed nanotech-based innovation and improve the opportunities of collaborative research; reinforcement of research staff; refinement of management capacities; innovative dissemination actions both for specialists and broader audience; development of a strategic plan for the IP. The multidisciplinary partnership included top class scientists from UK, Spain, France, Germany and Norway, local authorities, representatives of ministerial institutions, water treatment SME and filters technology world Leader company, to guarantee the effectiveness and sustainability of the Action.
WATER aimed to transfer our skills and know-how in the field of nanotechnology to an innovative application relative to water purification. Such action was also contextualized in a joint effort with SME and local administration to achieve in our territory a “culture of water”, that means not only the development of a technology for water purification, but also the growth of a broader concept of water management.
A recent review article “Solar photocatalysis for water disinfection: materials and reactor design”, by D.A. Keane et al. (Catalysis Science & Technology 4, 1211 (2014)) claims that “...access to clean drinking water is a human right according to UN regulations. The significance of using immobilised catalysts over the catalyst powder in slurries is also highlighted. It is noted that, despite encouraging early field studies, the commercialisation and mass production of solar photocatalysis systems remains highly challenging.”
With respect to the state of the art, we have critically examined the advantages of some approach and have decided to focus our efforts into the realization of photocatalytic materials, immobilized in a matrix, that are active in the solar light. The technological impact was represented by the realization of photocatalytic nanomaterials, up-scalable to industrial production, to be used in water purification systems. This innovation was coordinated with some SMEs, that participated to the project with an official role ratified by a MoU. This technologic development promises to sustain the economy of the Ionic Sicily, by improving the quality of the sea water through innovative treatment of waste water, flowing into the ground of coastal towns as allowed by the local legislation.
Our scientific strategy had an impact in terms of 1) scientific production (28 JCR publications), 2) visibility (20 presentations at international conferences, 4 awards, several independent mentions on the media) 3) cultural growth of the team (attendance to top level courses on management and communication), 4) relationship with SME (2 MoU signed, 2 companies among the partners). Furthermore, WATER gave an impulse to induce a change of the local mentality, by the affirmation of a long-term vision and strategy in a common scientific and social context, hopefully to see a new generation growing in a fairly productive environment, projected towards the desired change of mentality. WATER has represented a breakthrough, but the tsunami it caused has still to calm down.
Project Context and Objectives:
The Seventh Framework Programme should contribute towards promoting growth, sustainable development and environmental protection [DECISION No 1982/2006/EC].
Worldwide, 1.2 billion people lack access to sufficient amount of clean water and 2.6 billion people lack adequate sanitation. Having adequate water supplies, and removing pathogens, chemicals and new generation contaminants with high throughput at low cost is a growing challenge around the world. In particular, this issue is critical for a region entirely washed by the sea and affected by long periods of droughts, such as Sicily. Nanotechnology is expected to improve the actual water filtration technology and also drive down the prohibitively high costs of water cleaning.
We identified two great resources in the ionic area of Sicily: the Sea and the bright tradition of the Physics – and more recently the skills developed in the field of nanotechnology – at CNR Catania. These two resources met within the frame of a successful action in terms of water treatment by nanotechnology. CNR Catania has got a strong background in materials science and nanotechnology with specific application to electronic devices, photonics and energy. Silicon quantum dots, metallic nanoparticles, Carbon nanotubes, semiconductor nanowires, nanoporous membranes, functional organic metamaterials are just a few examples of nanostructures for which the scientific research in Catania is famous and esteemed around the world. The local know-how on nanomaterials contributed to develop – with the focused investments of WATER – novel applications that could attract new industrial and services assets and have a broad impact on the society.
Aci Castello, a small town in the Catania area with a protected sea region of EC interest, and the Marine Protected Area “Isole Ciclopi” have been selected as a pilot case to study the effect of nanotechnology applications for water treatment systems. The local authorities have been involved in the project since the early stage and they supported the action plan by providing documents about the sea water state. This was an innovative approach for our applied research that will have in this case a determinant social impact. In addition, the dialogue between science and society in Sicily should be intensified in order to develop a science and research agenda that meets citizens' concerns, and is aimed to reinforcing a public confidence in science.
A worldwide leader in water filtration system, ATLAS Filtri, supported WATER, giving the great added value of tangible purpose of technology transfer and the potential of effective application of the innovation produced by WATER.
We focused on the realization of smart functional photocatalytic materials, with the final outcome of water purification devices and systems up-scalable to industrial-scale production and application. WATER aimed to transfer our skills and know-how in the field of nanotechnology to an innovative application relative to water purification. Such action should also be contextualized in a joint effort with SME and local administration to achieve in our territory a “culture of water”, that means not only the development of a technology for water purification, but also the growth of a broader concept of water management.
A recent review article “Solar photocatalysis for water disinfection: materials and reactor design”, by D.A. Keane et al. (Catalysis Science & Technology 4, 1211 (2014)) claims that “...access to clean drinking water is a human right according to UN regulations. The major advantage of using photo-reactors is that they enhance disinfection by increasing photon flux into the photocatalyst. The significance of using immobilised catalysts over the catalyst powder in slurries is also highlighted. It is noted that, despite encouraging early field studies, the commercialisation and mass production of solar photocatalysis systems remains highly challenging.” With respect to the state of the art, we have critically examined the advantages of some approaches and have decided to focus our efforts into the realization of photocatalytic materials, immobilized in a matrix, that are active in the solar light. One of the main objectives, also in terms of size of the investment, was the realization of a new laboratory, equipped with state of the art instrumentation, for the synthesis of such photoactive nanomaterials to be used for water purification. For this action, we upgraded our facilities with a new research infrastructure for production of nanostructures on a large scale, i.e. the Atomic Layer Deposition (ALD) methodology. It has been demonstrated by Sandia National Laboratories and University of New Mexico that self-assembly and ALD can advance the field of membrane technology for water filtration.
During the second project year we have completed the realization of the facility, the installation of the equipment and the training for their use. The laboratory now is fully running and many materials produced by its equipment have been already synthesized and tested. Even a million Euro lab is nothing without the diligence of skilled and motivated scientists. Another important objective of WATER was that of training a group of top level researchers to operate in a fair atmosphere, with an efficient organization of roles and responsibilities. We indeed obtained this result, by forming an harmonious group where a sound spirit of competition exists, but always shaped to correctness and intellectual honesty. This situation was reached thanks to a delegating style permeating the team, with clear assignment of tasks, roles and merits, to a patient activity of interconnection between the subjects of the group and to an effort towards the establishment of an effective flow and exchange of information.
We have invited the President of CNR, Luigi Nicolais, to visit the WATER laboratory and had the great honor to receive his visit on January, 16th 2015. President Nicolais congratulated for the realization of this leading edge facility and appreciated the potential of the materials realized by our new equipment.
The main objective of the “Research Potential” program which we applied to in 2012 with the WATER proposal was “to unlock the research potential” of the applicant. We believe to have achieved such main objective thanks to the EC funding and to the careful fulfillment of the action plan negotiated with the EC. Our skills and scientific background were combined with state of the art equipment and a correct dose of visibility, as well as corroborated by efficient twinning measures and reinforcement of the human capital, both in terms of resources and of their cultural growth.
This was not only a research project, but a coordinated action led together with some actors of the local territory, such as the municipality of Aci Castello or the Marine Protected Area “Isole Ciclopi”. A hard task was to make the local scientific community understand that a Coordination Action is not only a research project, but a global social, economic and certainly also scientific action, led together with supporting partners and actors of the territory, aiming also to an intense dissemination of the ideas which the action relies on and of the relative achievements. While twinning with the supporting partners is a chance of cultural growth and scientific specialization, an effective dissemination plan to a broad public can favor a close link between scientific research and society. The dialogue between science and society in our territory was hence intensified in order to develop in the local society a better established feeling of trust in science and research.
In order to achieve these objectives an intense dissemination campaign was launched by WATER. A bright example is represented by the “Water Day”, a festival on science and water organized by our team in Aci Castello, the Municipality involved in the project. This event was devoted to get closer to the people, by showing the research results and explaining in simple words how such scientific highlights can be useful for the daily life. The methodology and the language for an effective conversation with the people, both adults and children, were refined along the WATER life thanks to the Communication course we attended at the beginning of the project. We are now definitely able to find the correct way to construct a fruitful dialogue with citizens having no scientific background, but eager to learn new concepts and driven by the curiosity of the research highlights. More than one thousand participants came to see what water, science and entertainment share in common. The Municipality supported such initiatives with the publicity on its facebook page as well as with the tweets of the Mayor. Further sustain to the dissemination initiatives always came from our stakeholders, both companies (Atlas Filtri, New Ecotecnica Sud, Fonte Nuova, Plastica Alfa) and public institutions (Marine Protected Area “Ciclopi Islands”). The relationship with these stakeholders was regulated by the drafting of a Memorandum of Understanding.
Another important objective is that of technologic transfer. The effective application of the innovation produced by WATER has been carefully examined together with the top technical and marketing management of the companies that signed a MoU, giving rise to the definition of a prototype for obtaining drinkable water from contaminate sources. Furthermore, from the basic scientific point of view we are making an effort to develop new synthesis methods that are relevant both for being published in high impact factor journals and for attracting the industrial interest for realizing conceptually new products. An example is represented by the growth of nanostructures in the Atomic Layer Deposition (ALD) system installed by the WATER funding at temperatures as low as 40 °C, potentially compatible with thermoplastic materials on which integrate them.
The conclusive objective, particularly related to the last semester, was the definition of an evaluation relative to the action. Indeed, this evaluation already untied since the early stage with a careful SWOT analysis ad, along the life of the project, with a continuous check of the success indicators reported in the work plan. The last phase of this evaluation process was represented by the meeting with three independent experts nominated by the EC, who came to visit the WATER team and the facilities realized by the EC funding. This moment of debate was tough, but also rewarding, and led the team to make a deep analysis of the achievements and of the unexpected consequences, positive or negative, of the action.
Project Results:
Description of the main S&T results
An intense research activity was performed during the WATER life, even though this was a coordination action. The reason lies in the technical boost given to the research level of our CNR Unit by the new equipment and in the psychological drive originated by the challenge of tackling new topics, i.e. water purification by functional photocatalytic nanomaterials. Thanks to the human resources sustained by the WATER funds, a significant effort was put in opening new research programmes. A synthesis of the main results is reported in this document.
Plasmon enhanced photocatalysis in TiO2/Ag/TiO2 nanocomposite films
Due to its wide band-gap, TiO2 absorbs only in the UV range of the electromagnetic spectrum. However, sunlight contains a small amount of UV photons (~5%). Thus, in the last 20 years have been developed several strategies devoted to increase the efficiency of titanium dioxide under visible (solar) irradiation. Among the most extensively studied methods, we are interested, in particular, in the use of plasmonic metal nanostructures. Plasmonics exploits the physics of collective oscillations of free electrons in metals, induced by the interactions with electromagnetic radiation, typically in the visible range. Plasmonic metal nanostructures can interact with a photoactive substrate increasing the probability of light absorption, leading o field enhancement and non-linear effect in the vicinity . The advantage of the formation of e-/h+ pairs, close to the semiconductor surface, is that these charge carriers are readily separated from each other and easily migrate to the surface, where they can perform photocatalytic transformations.
To further enhance the plasmonic effects of metal nanostructures, we engineered the optical response and thickness of a Ag/TiO2 nanocomposite film. Our results clearly demonstrate that the proper thickness engineering is the key to take simultaneously advantage of spectrally and spatially localized surface plasmon resonance (LSPR) and optical amplification. Indeed, combining TiO2, a high refractive index material, with Ag, known for its excellent plasmonic properties, we obtained a highly enhanced optical response in the visible range. Pursuing this idea, we obtained, via sequential sputtering and annealing, a TiO2/Ag/TiO2 nanocomposite showing photocatalytic activity under visible illumination according to the discoloration of the Methylene blue dye. We compared two TiO2/Ag/TiO2 nanocomposite films with and without the field enhancement conditions induced by the thickness engineering of the film. We also measured the activity of a bare TiO2 film whose 10 nm-thick superficial layer was prepared following the same procedure of the capping layer of Ag NPs. MB degradation occurs under irradiation; therefore we report also the degradation of a vessel not containing photocatalytic material as reference. We observed that, as expected, TiO2 is not active under visible illumination. The fundamental result of the test was that, despite having the same composition and superficial morphology, the two TiO2/Ag/TiO2 nanocomposite film showed completely different behavior. In particular, the film matching the plasmonic field enhancement conditions is able to decompose the MB dye, showing a good photocatalytic activity in the visible range, while the film outside these conditions appeared to be not active. These results underline the importance of a proper optical engineering of the supporting matrix for plasmon enhanced applications. Such substrate is an ideal candidate for solar-driven photocatalytic reactions.
Improvement of the photocatalytic efficiency of nanostructured TiO2
As part of the WATER project, we have opened several lines of research centered on the titanium dioxide. The aim was to increase the photocatalytic efficiency of the material in order to make it more efficient in the purification treatment of the water. The methods to enhance the photocatalytic properties of TiO2 are mainly based on the inhibition of the photo-generated electrons–holes recombination, on the increase of the exposed surface area, and on the decrease of the TiO2 band-gap energy that hollows the absorption of visible light to generate electrons-holes couples. In this context, we have obtained the following results:
We propose a ground-breaking approach by an upside-down vision of the Au/TiO2 nano-system in order to obtain an enhanced photocatalytic response. The system was synthesized by wrapping Au nanoparticles (8 nm mean diameter) with a thin layer of TiO2 (4 nm thick) deposited by atomic layer deposition (ALD). The novel idea of embedding Au nanoparticles with titanium dioxide takes advantage of the presence of metal nanoparticles, in terms of electron trapping, without losing any of the TiO2 exposed surface, so as to favor the photocatalytic performance of titanium dioxide. The remarkable photocatalytic performance together with the stability of the nano-system was demonstrated by degradation of the methylene blue dye in water. The non-toxicity of the nano-system was established by testing the effect of the material on the reproductive cycle of Mytilus galloprovincialis in an aquatic environment. The originally synthesized material was also compared to conventional TiO2 with Au nanoparticles on top. The latter system showed a dispersion of Au nanoparticles in the liquid environment, due to their instability in the aqueous solution that clearly represents an environmental contamination issue. Thus, the results show that nanometric TiO2 wrapping of Au nanoparticles has great potential in eco-friendly water/wastewater purification.
Another possibility to increase the photocatalytic activity of titanium dioxide is given by the use of nanostructured systems, such as: nanoparticles, nanotubes, nanowires, etc... TiO2 nanostructures can offer advantages such as high surface-area-to-volume ratio, enhancing in this way the amount of the photo-generated charges. However, there are some issues that strongly limit their application: poor light penetration due to nanostructures agglomeration and the post-recovery of the same after the water treatment. Based on the above-mentioned considerations, we studied the photocatalytic activity of a TiO2 thin film covering a nanostructured Si template in degrading dyes in water. The titania film (10 nm thick) was deposited by Atomic Layer Deposition. This approach avoided the use of nanoparticles and their consequent dispersion in water. The obtained results show that the excellent conformality of the titania film on high aspect-ratio Si nanostructures is responsible for the improved efficiency in degrading dyes in water. In particular, the nanostructured TiO2 exhibited a photo-degradation reaction rate for the methylene blue and methyl orange that is approximately 3 and 12 times the rate of the TiO2 film with the same macroscopic area, respectively. Thus, our results demonstrate that the TiO2 thin film coating of nanostructured surface can be efficiently used for water treatment reactors.
The development of photocatalysts that can operate under visible light will allow the use of the main part of the solar spectrum. One useful approach has been to dope TiO2, in particular with nitrogen, carbon, transition metals. Metal ion implantation has been reported as an effective method to improve the visible light response of TiO2. However, we have reported that ion implantation is responsible of the loss of the photocatalytic efficiency in the UV region, due to the kind of defects introduced. Recently, black hydrogenated TiO2 has received extensive interest, and it is considered to have a great potential due to its extremely enhanced absorption in the visible and infrared region. The synthesis of hydrogenated titania usually involves commercial Degussa P25 TiO2 or titania nanorods and nanotubes. The hydrogenation is always carried out in a tube furnace, with a temperature in the range of 200–550ºC, in a high pressure H2 atmosphere (up to 20 bar), and for an exposition time from 3 h to 5 days. We employed hydrogen peroxide etching of Ti films as an easy, rapid, and low-cost method to synthesize hydrogenated TiO2 nanoplumes with significant photocatalytic properties under UV and VIS light irradiation. This TiO2 nanostructure and its synthesis are totally original. In particular, the synthesized nanoplumes have a significant efficiency in degrading methylene blue organic compound and a good antibacterial activity under VIS light irradiation. The presented synthesis process may be applied for the fabrication of efficient hydrogenated photocatalytic materials as an alternative to high temperature and high pressure approaches. In addition, the proposed method is industrially scalable, with relatively low cost, and with no environmental impact.
Advanced synthesis of ZnO for photocatalysis
The uses of ZnO as a photocatalytic degradation material for environmental pollutants has been extensively studied, because of its nontoxic nature, low cost, and high photochemical reactivity. ZnO probably has the most abundant forms of any known material. ZnO has emerged to be more efficient catalyst as far as water detoxification is concerned because it generates H2O2 more efficiently, it has high reaction and mineralization rates, and also it has more numbers of active sites with high surface reactivity. The properties of ZnO are strongly dependent on its structure, including the morphology, aspect ratio, size, orientation, and density of crystal. We focused our research in three different materials. The photocatalytic performance of the investigated materials was tested in detail by the photo-degradation of Methylene Blue (MB) and phenols in water.
ZnO nanofibers (ZnO NF) with and without Pt nanoparticles (NPs) fabricated by the electrospinning method. We synthetized two different kinds of nanofibers: with and without Pt Nanoparticles. The synthesis of the Pt NPs was performed by pulsed laser ablation in water. The solution, contained a Zinc precursor and eventually 1% of Pt NPs, was electrospun using a commercial electrospinning apparatus. In order to remove the polymer after the electrospinning process, the composites were annealed at 500 °C, for 1 h, in a conventional furnace under a controlled oxygen atmosphere (2.5 l/min). The SEM and TEM analysis showed that both electrospun ZnO nanofibers, enriched with Pt NPs and without them, have a mean radius ~ 50 nm. The addition of Pt nanoparticles improves the nanofibers photocatalytic activity of ZnO in the degradation of methylene blue. In particular, the Pt-ZnO NF exhibited a photo-degradation reaction rate that is ~ 40 % higher than that observed for mere ZnO nanofibers. The fibrous structure, that facilitate the contact of nanofibers with the dye, together with the presence of Pt, that improves the separation of charge carriers, makes Pt-ZnO a promising candidate for photocatalytic applications.
ZnO nanorods (ZnO NR) synthetized by the Chemical Bath Deposition (CBD) technique. ZnO seed layers were deposited on Si substrate by ALD, with a Picosun R-200 Advanced system. During the deposition, the temperature was kept at 300 °C. The deposition cycles was varied from 25 to 250 cycles, so to obtain three different thicknesses: 3 nm, 10 nm and 30 nm. Aligned ZnO NRs arrays were synthesized using a CBD method at atmospheric pressure. ZnO NR grown by CBD onto extra-thin (3 nm) and extra-smooth (RMS < 0,2 nm) ALD seed layers have shown excellent photo-degradative properties towards methylene blue dye and phenols. The thickness (and related roughness) of ALD seed layer is proven effective to trigger the ZnONRs overall density, ultimate responsible for the observed variation of photocatalytic activity (towards methylene blue and phenol degradation in water) of obtained supported ZnO nanostructured.
ZnO thin films (ZnO TFs) deposited by Atomic layer deposition at low temperature. ZnO films with different thicknesses (from ~ 9 to ~ 48 nm) were deposited. During the deposition, the temperature was fixed at 40, 80 or 120 °C in order to understand the effect of the temperature in the ZnO films crystallinity and morphology. XRD analyses proved the polycrystalline structure of the ZnO films, even for the samples deposited at 40 °C, despite the low deposition temperature. The photocatalytic activity of the materials was investigated, by the MB degradation, as a function of the film thickness and the deposition temperature. We found that for ZnO films deposited at 80 °C a surface region of ~ 20 nm contributes the charge carriers to the photoreactions. The trend of the photocatalytic activity with the deposition temperature appeared strongly dependent on the crystallographic orientation of the films. In particular, the samples deposited at 80 °C showed the best photocatalytic performance, since the (002) orientation prevails. Finally, we fabricated flexible photocatalytic films by depositing by ALD at 80 °C a thin film of ZnO on polyethylene naphtalate (PEN). The films showed a significant efficiency in the photo-degradation of MB and phenols in water.
Polymeric nanocomposites for water purification
TiO2 nanostructures have a great potential as very efficient photocatalysts due to their large surface area, in fact a higher surface/volume ratio increase the reactivity. However, significant limitations exist for the use of nanomaterials due to their impact on human health and ecosystems. Until now, available information is insufficient to determine the toxicity or the highest allowable concentration of a particular nanomaterial in drinking water. In addition, if nanomaterials are applied in the form of dispersion, after water treatment, an efficient separation process is required. Slurries of TiO2 are often treated in photoreactors, which produce fast water purification from organic pollutants and bacteria. Nevertheless, such plants require a high energy consumption and a secondary filtration to separate the nanomaterials from water. Our approach is alternative to the use of nanomaterials dispersed in water, it based on the incorporation of several nanomaterials into polymeric composites as a valid solution to overcome these problems.
Such nanocomposites were synthesized using poly (methyl methacrylate), a common thermoplastic material, as polymer matrix. These composites with PMMA are stable, harmless, cheap and they can be realized in a freestanding form by a simple and low-cost method of solution casting, allowing a potential industrial application as efficient tools for the removal of organic and bacterial contaminants from water. The photocatalytic activity of the samples was evaluated by the degradation of two different dyes (methylene blue and methyl orange) and phenols in an aqueous medium adapting the methodology with the current ISO10678:2010 test, as well as we tested the antibacterial activity by measuring the survival rate of Escherichia coli, as a model organism, after exposure to light activated samples.
PMMA films with different contents of TiO2 nanoparticles were realized and tested. They display a very high UV photocatalytic efficiency, compared to other immobilized photocatalytic materials reported in the recent literature. In addition, the stability of these photocatalysts was evaluated re-using the same fragment of PMMA/TiO2 film for the degradation of methylene blue. The photocatalytic activity does not significantly change after several cycles, suggesting that PMMA nanocomposites can be efficiently recycled and reused for repeated cycles without loss of efficiency. No NPs were released from the material as attested by the absence of any photocatalytic activity when the samples were extracted from the solution. For the antibacterial activity, after 1h exposure to the PMMA/TiO2 film (1 cm2) with 15wt% NPs and UV, E. coli survival rate has been reduced up to ~30%.
Furthermore, to obtain an higher degradation rate, titanium dioxide nanoparticles combined with single walled carbon nanotubes (SWCNTs) were embedded in the polymeric films. SWCNTs act as acceptor of electrons, improving the charge separation process; in this way a significantly higher photocatalytic efficiency under UV irradiation was obtained, compared to the systems with TiO2 only.
The main problem of the TiO2, that limits its application especially in the large-scale industry, is the value of its band gap ̴ 3.2 eV), allowing an absorption only in the ultraviolet range (λ < 387 nm). Photoactive materials even under visible light were synthesized thanks to the functionalization of the TiO2 nanoparticle surface with meso-tetraphenylporphyrin-4,4’,4’’,4’’’-tetracarboxylic acid (TCPP) as dye sensitizer. The efficiency of degradation of methylene blue under visible light in contact with this sample is comparable to the efficiency obtained with the film of PMMA with only TiO2 nanoparticles, but under UV light. The antibacterial activity of the films with the porphyrin was tested with a visible lamp. The visible light promotes bacterial growth, in fact bacteria exposed to visible light only and to PMMA and visible light were able to double after 1 hr exposure, if compared to the untreated sample. However, in the presence of the film with TiO2 impregnated with the porphyrin, the E. coli survival rate has been reduced up to around 60%. These results are crucial for the application of these nanocomposites as solar photocatalysts, very useful for portable applications and/or use in disadvantaged areas.
Photoactive nanocomposites by direct transferring of anodic TiO2 nanotubes to commodity thermoplastics
TiO2 nanotubes (TNT) have demonstrated to be a versatile nanostructure for biomaterials, clean energy and water remediation applications at lab-scale. However, the cost of titanium and the poor mechanical properties of the nanotubes hinder their adoption at large scale. In this research line, we developed a straightforward and scalable method for transferring photoactive anodic TiO2 nanotubes from titanium foils to commodity thermoplastic polymers (TP), polypropylene (PP), polyethylene terephthalate(PET), polycarbonate (PC), and polymethylmetacrylate, allowing the reusing of titanium. The obtained composites present comparable photoactivity (ISO-10678:2010) and antibacterial properties than TiO2 nanotubes on titanium with the advantage to be pliable. This approach allows a low-cost fabrication of a photoactive nanocomposite material. After the synthesis, the composites shows proper retention of the TNT, mechanical flexibility and pliability.
The Photonic efficiency (PE), measured by the ISO-10678:2010 protocol (Fine ceramics — Determination of photocatalytic activity of surfaces in an aqueous medium by degradation of methylene blue. ISO 10678:2010(E). International Organization for Standardization (2010). Switzerland), resulted to be about 0.025 %, comparable with that of a commercial product. The TNT/TP compositesl show bactericide properties.
We have hence obtained an economic, easy and accessible methodology for transferring TNT from Ti foils to various commodity TP to obtain pliable photoactive nanocomposites with the possibility of reusing the Ti. This, together with the simplicity and the possibility to use basic equipment and recycled raw materials, makes the presented technique a promising route for the industrial synthesis of these composites not only for environmental application but also in different fields such as sensing and biomaterials.
Carbon nanotubes mixed with titania nanoparticles
Common photocatalytic materials are semiconductor oxides. Among these materials, the most widely used in water splitting technique and in photocatalysis is titanium dioxide (TiO2) because of its easy availability, long-term stability and relative non-toxicity. One of the limiting factor of TiO2 photocatalytic activity is the fast electron-hole recombination times (10-9 s) with respect to typical time scale of chemical interactions (10-8 ÷ 10-3 s) induced by the photocatalyst surface on the molecules in contact with it. A lot of strategies have been proposed to overcome these limitations. One of these approaches is to increase the lifetime of the electron-hole pair by trapping the electrons, and this can be achieved by integrating TiO2 with transition metal ions or heavy metals or carbonaceous materials.
Among carbon based materials, nanotubes (CNTs) are widely used, coupled with TiO2, for the improvement of the photocatalytic efficiency of the semiconductor oxides. In many works, mixed CNT-TiO2 nanoparticle powders are dispersed in solution, but this process has some drawbacks, such as the permanency of the photocatalytic materials in the solution and the difficulty to reuse the same photocatalyst more than once. The deposition of nanomaterials with photocatalytic properties on a suitable substrate, without significant release of CNTs and nanoparticles in the water to be purified, would allow to go beyond these problems.
We have used electrophoretic deposition (EPD) to deposit anatase TiO2 nanoparticles and multi-walled Carbon Nanotubes (MWCNTs) composite layers on Pt/SiO2/Si substrates. EPD is a cost-effective method usually requiring a simple equipment allowing to fabricate uniform coatings with excellent macroscopic homogeneity.
The photocatalytic properties of mixed layers, with different MWCNTs/TiO2 weight ratios (CNT:np-TiO2 ratio in solution increases between 0.1 and 0.75) and TiO2 nanoparticles were compared by using the photocatalytic discoloration of Methylene Blue (MB) under UV-Vis irradiation provided by a solar simulator. The composite layers were characterized by scanning electron microscopy (SEM), Energy Dispersive X-ray analysis (EDX), and photoluminescence (PL) measurements in order to explain the different photocatalytic behaviours observed for each material.
The sample with the best photocatalytic properties is found to be the one prepared with a CNT:TiO2 ratio of 0.5 and it also shows the lowest PL intensity. Indeed both the effects can be related to the electron trapping phenomenon that induces a hindering of the electron-hole pair recombination. For the largest relative amount of CNTs (CNT:TiO2 ratio of 0.75) the photocatalytic efficiency decreases and PL peak intensity increases again. Both the effects could be related to an excess of CNTs covering the TiO2 surface.
Any possible reduction of the MB concentration due to adsorption phenomena on the catalyst surface has been evaluated by keeping MWCNT/np-TiO2 composite samples in MB solution in dark conditions at different temperatures (at room temperature and heating the solution on a hot plate at 50°C) for the same time used in the irradiation process. No significant MB reduction due to adsorption phenomena on the photocatalyst surface has been observed in all the solutions by absorbance measurements, therefore the observed MB reduction is imputable only to degradation of the molecule and not to a mere adsorption on the photocatalyst surface or to a temperature effect.
Furthermore, the possibility to use the same samples more than once was verified by repeating the photocatalytic process (immersion of the photocatalyst in MB solution and irradiation) for three times and evaluating the efficiency of the process: the effect on the MB degradation remains unchanged at least for three consecutive processes.
Graphene oxide and graphene oxide reduced by pulsed laser ablation.
In general, graphene-based materials for large-scale production can be obtained from graphene oxide (GO) by reducing the number of oxygen functional groups by means of suitable treatments. The composition and the structure of GO and reduced GO depend on the synthesis and reduction methodologies.
Within the WATER Project, GO and modified GO have been investigated in order to better understand their chemical/physical properties and use them suitably for applications in water purification. We prepared GO by a modified Hummers method and reduced it by pulsed laser irradiation using visible wavelength (532 nm). Transmission electron microscopy analyses were performed and dual electron energy-loss spectra were acquired in different regions of GO and reduced GO (rGO) flakes. Experimental results showed a series of characteristic peaks related to C and O K-edge shells. Density functional theory calculations of the high-loss region of the electron energy loss spectra at atomic level enabled a reliable correlation between the observed experimental peaks to the presence of different oxygen functional groups on the graphene surface and the corresponding atomic configurations.
In particular, we were able to distinguish among the features related to C atoms in the vicinity of C–OH bonds, C-O-C bonds and O-in-vacancy sites. In the explored areas, the percentage of epoxy groups (C-O-C) prevails over the hydroxyl groups. Moreover the π2* peak was indicative of highly oxidized regions.
The oxygen EELS spectrum can be explained by the presence of functionalities with different configurations and local concentrations, confirming the inhomogeneous nature of graphene oxide. The differences between GO and rGO observed in the C and O K-edges spectra were satisfactorily explained by theoretical calculations.
Mixing of graphene oxide/reduced graphene oxide with titania nanoparticles
Recently, graphene and graphene oxide (GO) are drawing much attention as alternative materials for dyes adsorption. Graphene is defined as a flat monolayer of sp2 bonded carbon atoms, packed tightly into a two-dimensional honeycomb lattice. GO is generally prepared by chemical oxidation of graphite powder resulting in extended graphene sheets decorated with epoxy and hydroxyl functional groups in the basal plane and carboxylic acid groups at the edges. These groups confer high hydrophilicity and negative charge density to GO, favouring the adsorption of cationic species as the methylene blue (MB) azo-dye, due to electrostatic interaction. MB can form different aggregates on GO producing maxima of light absorption at specific wavelengths.
GO and reduced GO (rGO) by pulsed laser ablation in liquid (PLAL), using visible wavelength (532 nm), were tested for dye removal. PLAL, with respect to other reduction methods, is more environmentally friendly and allows to tune gradually the density and quality of the oxygen functional groups on GO. In addition, we have tested PLAL as a new, simple and green method for the synthesis of GO (rGO)–TiO2 composite materials.
The interest for this kind of hybrid materials arises from the photocatalytic activity of TiO2 for water purification. Hybrid compounds containing GO and TiO2 (P25) nanoparticles were realized to get a better dispersion of the semiconductor oxide on a wide surface area and to increase the absorption of light in the visible range. Anyway, since GO shows higher MB adsorption capacity than other absorbent materials, such as carbon nanotubes and activated carbon, it is important to test also the adsorption properties of the hybrid compounds.
We have tested the ability of GO-(rGO-)TiO2 composites to remove a cationic dye such as MB from water by simple adsorption phenomena. In particular GO was irradiated by laser for different times (15’, 60’ and 180’) and the produced rGO materials are identified as rGO15, rGO60 and rGO180 respectively.
Interestingly, the aggregation of dye cations varies depending on GO superficial characteristics and therefore it is interesting to study and compare the efficiency of GO and its laser reduced forms for the adsorption of MB in water. When GO and rGO were added to the MB solution an aggregation phenomenon immediately occurred and the concentration of the residual MB rapidly dropped down.
MB aggregation depends on GO concentration that was varied between 10 and 100 mg/l: at the lowest concentration, the peak at 577 nm indicates the formation of MB trimer while the second peak at 668 nm is due to the monomeric form. As the GO concentration is increased the maximum of the curves shifted to higher wavelength due to a lower MB aggregation on the GO layers: the peak related to the trimer disappears and the peaks of dimer and monomer are predominant.
For 70 mg\l GO a shoulder at 577 nm is still present indicating the presence of trimers. MB adsorption occurs by three regimes corresponding to (1) isolated MB on GO, (2) MB molecules interacting as “H” dimers on GO and formation of aggregates, and (3) MB saturation of GO surface and subsequent precipitation. The three regimes depend on the relative concentration of GO layers and MB molecules in water: when GO concentration is high enough, MB molecules can distribute homogeneously on the GO surface without interacting with other molecules; as the GO concentration is reduced the adsorbed MB can interact more easily and aggregation occurs, with the formation of trimers. In addition, the MB aggregation on GO depends on oxygen distribution on its surface: the number and size of aggregates decreased in favour of monomers with increasing the reduction time in accordance with the lower charge density of rGOs with respect to GO. The absorption of cations is reduced and the large distances between negative neighbouring sites cause relatively large distances between adsorbed cations. The effect of lowering the charge density of GO is detectable by MB adsorption, and is also observable for GO/rGO180-P25 solutions.
For 90 mg\l TiO2 solution no MB adsorption takes place, whereas it occurs immediately if GO and rGO180 are added. The spectrum of GO-P25 solution does not show a predominance of the trimer-related peak as GO, but it is more similar to the case of rGO180. Indeed in this case the oxygen availability on GO layer is reduced and this is probably due to the interaction of TiO2 with GO that could enhance the reduction of GO or favour the formation of TiO2-GO aggregates. This effect is less evident in the case of rGO180-P25 solution since the initial graphene oxide is poorer of oxygen moieties.
Antibacterial properties of graphene oxide and reduced (irradiated) graphene oxide
Although disinfection methods currently used in drinking water treatment can effectively control microbial pathogens, research in the past few decades has revealed a dilemma between effective disinfection and the formation of harmful disinfection byproducts (DBPs). Chemical disinfectants commonly used by the water industry such as free chlorine, chloramines and ozone can react with various constituents in natural water to form DBPs, many of which are carcinogens. Therefore, there is an urgent need to reevaluate conventional disinfection methods and to consider innovative approaches that enhance the reliability and robustness of disinfection while avoiding DBP formation. Recently, several natural and engineered nanomaterials have been investigated as possible alternative disinfection methods. Among these materials, carbon-based materials and, in particular, graphene and its derivatives are receiving increasing consideration.
In this work, our idea was to modify the graphene oxide (GO) in a controlled way in order to reduce slightly the amount of oxygen and keep the material still well dispersible in water, since a good dispersibility helps to favour the contact with bacteria eventually present in the water solution. The irradiation of GO was performed by a pulsed visible laser directed in an aqueous solution of GO and the antibacterial activity of GO and GO irradiated at different times (up to 4 hours) was evaluated. In the following we will speak about irradiated GO (iGO), instead of reduced GO, in order to highlight a general modification of GO, instead than a simple decrease of the oxygen concentration. The structural and chemical properties of irradiated graphene oxide (iGO) were studied by UV-Vis optical absorbance, Raman and X-ray photoelectron (XPS) spectroscopies, scanning electron microscopy (SEM) and dynamic light scattering (DLS) technique. The antibacterial activity was tested by using Escherichia coli ATCC25922 as a model organism.
Bacterial survival test and WST-assay (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium) were used. In order to investigate the mechanism of action, the level of lipid peroxidation in the bacterial membrane was tested as well as the integrity of bacterial membrane was observed by scanning electron microscopy images. Moreover, environmental safety of the analyzed compounds was investigated through the Fish Embryo Toxicity (FET) test. FET test is a modern toxicity test representing an effective alternative to acute test with adult fish. In fact, fish embryo-larval assays provide a screening and investigative tool able of testing a larger number of nanoparticles.
In our experimental system, GO irradiated for 3 and 4 hours (iGO3 and iGO4 respectively) displayed the best results as antibacterial materials, as assessed on E. coli, at concentration of 20 mg/l. Such better activity was correlated to the morphology and the size reduction of the irradiated GO flakes that becomes similar to the bacteria size. Moreover, the laser irradiation of GO in water solution preserves the oxygen content at reasonable concentration to make the iGO solutions highly dispersible in water. This effect is essential to have a good interaction between nanomaterials and bacteria in water. Fish Embryo Toxicity test showed that neither mortality nor sublethal effects were caused by the different kinds of GO tested at concentration eight times larger than 20 mg/l. Furthermore, pulsed laser irradiation of GO is an environmental friendly process that avoids the use of chemicals. The efficient photocatalytic rate, the antibacterial properties and the absence of toxicity make iGO a promising green option for possible applications dedicated to water purification.
Nanocomposite polymeric membranes for water purification.
In the last decades the development of efficient and ecologically-friendly methods to remove contaminants from water has become of fundamental importance, since pollution is increasing drastically. Recent advances in nanotechnology suggest that many of the issues involving water quality could be resolved or greatly ameliorated using nanoparticles, nanofiltration or other products resulting from the development of nanotechnology.
Several papers in the literature show the use of TiO2 powder, carbon nanomaterials or a combination of both, dispersed directly in the solution that is going to be treated.
After the photocatalytic process the photocatalyst has to be removed by processes not always easy and fast. Furthermore, the catalyst cannot be easily used again.
A possible solution is to incorporate the photocatalytic nanoparticles in polymeric membranes, that can be removed from water and regenerated for further use after purification processes.
Hybrid nanocomposite Nafion membranes for azo-dye (methyl orange) degradation
We have prepared hybrid Nafion membranes, using various fillers, such as anatase-type TiO2 nanoparticles, graphene oxide (GO) and organo-modified graphene oxide (abbreviated as GOSULF) for water purification applications. Scanning electron microscopy analysis confirmed the homogeneous dispersion of the fillers. The photocatalytic properties of the hybrid membranes were evaluated using the azo dye methyl orange (MO) in aqueous solutions.
The two main effects contributing to the decolourization of the dye, adsorption in the membrane and degradation in solution, were investigated in detail.
MO concentration is reduced by dipping the membranes in solution both in dark conditions and under irradiation, but a stronger effect is observed under irradiation. In particular, the best results are achieved for Nafion–TiO2 and Nafion–GOSULF and they are compared with photocatalytic activity shown by the fillers directly dispersed in MO solution. Nafion–TiO2 under irradiation shows photocatalytic activity for degradation of MO with the formation of by-products, as already reported for TiO2 powder dispersed in MO aqueous solution. The photoactivity of GOSULF has been shown for the first time, but Nafion-GOSULF is more efficient in the dye removal, showing very promising results: after 3 h UVA/blue lamp irradiation a residual MO concentration of less than 30% of the initial value is found, without leaving any other harmful by-products in solution.
This indicates that Nafion can be used as a matrix in which TiO2 and GOSULF can be incorporated, with no photocatalytic efficiency reduction with respect to the same fillers dispersed directly in solution. Among the Nafion membranes under investigation, Nafion–GOSULF, for the first time used for water purification purposes, showed the most promising results in MO adsorption and photocatalytic degradation. We have demonstrated that such membranes may be regenerated and used for several MO removal processes.
Sulfonated graphene oxide nanosheets, as a powder or embedded in polymeric matrix, for cationic dye degradation
Organo-modified GO containing sulfonilic functional groups (GOSULF) was produced by reaction with an acidic amine derivative covalently bonded to the graphite surfaces via nucleophilic substitution reactions on the epoxy groups of GO (see Fig. 1).
GOSULF was then dispersed into an ionomer, such as Nafion® (DuPont), in order to create nanocomposite membranes. Nafion® is a perfluorosulfonic polymer that shows significant properties such as high ionic conductivity, ion-exchange capacity and stable structure, and therefore it is used for various applications such as fuel cells, sensors, and electrochemical devices. The choice of this ionomer for the creation of hybrid films to be tested in water purification applications is substantially linked to two reasons: (1) the acidic properties promote the separation of ionic compounds present in the water and (2) the Nafion membranes have a high capacity to absorb water favouring the effective interaction between contaminants and the active material. The organo-functionalization of the GO surfaces with hydrophilic groups, such as –SO3H, improves both the acidity and the water uptake of the resulting nanocomposite membranes, but also their mechanical, chemical, and thermal strength. Recent results show that GOSULF nanosheets exhibit a better absorption capability in the removal of MB with respect to the GO powder.
We have investigated and compared the degradation ability of GO and GOSULF flakes for removing methylene blue (MB) molecules from water in the dark and under UVA/blue illumination. Furthermore, a specific study on the Nafion–GOSULF composite membrane in the removal of MB was performed and the results compared with the case of methyl orange (MO) removal.
The degradation of MB is larger when GOSULF is directly dispersed in dye solution with respect to the case of GOSULF embedded in the polymeric matrix. MB adsorption by GOSULF occurs immediately and it is larger in comparison with the adsorption capacity of Nafion–GOSULF; it is also known that the adsorption of dyes on the surface of photocatalytic materials is needed in order to achieve dye degradation. Adsorption on GOSULF nanoparticles is favoured with respect to the adsorption on Nafion nanocomposites since in the former case the active sites are immediately accessible to MB molecules, while in the latter case the MB molecules have to diffuse inside the polymeric matrix. Nevertheless, the powder incorporation inside a polymeric matrix gives the advantage to overcome the problems related to the recovery of materials at the end of the process and nanocomposite Nafion membranes can be reused for several purification processes.
Indeed, the possibility of regeneration and reuse of the Nafion–GOSULF composite was also verified in order to demonstrate that the incorporation of nanomaterials inside a polymeric film is a more efficient and ecologically friendly method with respect to the direct dispersion of powders in aqueous solution.
TiO2 Nanowires for water purification
Titanium dioxide or titania (TiO2) is a well-known material that demonstrated optimal photocatalytic proprieties together with various advantageous features, such as long lifetime of excited electrons, nontoxicity, long-term chemical stability, high corrosion resistance and relative low cost.
Its photocatalytic properties are optimal for application in the sector of water purification. Indeed, the photocatalytic reactions generated by TiO2 when exposed to ultraviolet irradiation in the presence of water, decompose organic compounds (e.g. bacteria, pharmaceutical pollutants) decomposing them into carbon dioxide and water. These reactions are a surface based mechanism; therefore, a larger surface area in contact with water will increase the number of the photocatalytic reactions. For this aim, we investigated the synthesis of TiO2 nanowires (NWs) in order to increase the exposed surface area and improve the final photocatalytic efficiency.
TiO2 NWs were synthesized by seed assisted thermal growth on a Ti substrate. This method is widely used with various materials but many of its aspects are not well understood yet.
A Ti foil was coated with a thin film of Au (5 nm) and then processed in a furnace at temperatures between 600-1000 °C for 1 to 4 hours in a mixed gas flow of Ar and O2. The analysis of NWs by scanning electron microscopy obtained in these different ranges of temperature, annealing time, and gas flow, allowed to identify specific optimal conditions for the TiO2 NWs growth in terms of their length, density and uniformity of their areal distribution, and robustness of the sample: 800°C, 4h, 7.5 lpm of O2 and 10 lpm of Ar. The obtained NWs were about 2-3 µm in length and 50-200 nm in diameter with an Au nanoparticle on their top, indicating the mechanism of seed assisted growth.
Structural characterization of the NWs by X-Ray Diffraction revealed a TiO2 rutile crystalline phase with a main peak of the (110) orientation. Transmission electron microscopy indicated that the NWs are pure rutile TiO2 monocrystalline and that their growth direction corresponds to the <110>. An in situ thermal growth (carried out at the University of Oslo) in water vapor atmosphere, showed that the rate of NWs growth in length and density is higher in the first 20-40 minutes and that subsequently the oxidation rate decrease and the NWs tent to shorten and became wider in their base, creating a more wide rods/grains shapes.
The seed assisted growth mechanism occurred by Au forming nanoparticles because of a de-wetting process and catalysing the growth of nanowires; Ti diffused from the substrate up to the Au surface, formed TiO2 by reacting with oxygen and the TiO2 nanowire elongated along a main growth direction. Ti diffusion from the substrate is also indicated by the tapering shape of the NWs, which are characterized by a wide base. Since NWs are not nucleated without gas carrier (in vacuum) we can conclude that the nucleation mechanism cannot be only supported by the surface migration of Ti from the substrate but a certain amount of Ti has to be transported also in the gas phase. This means that the formation of pure Ti NWs is not energetically or kinetically favoured in the full range of explored temperatures (600-1000 °C). Moreover, without catalyst the NWs growth is very difficult to be induced and controlled, only few NWs are observed in small isolated areas of the sample with no reproducibility. To sum up, our experimental results revealed that the seed assisted growth of TiO2 NWs is a very complex synthesis mechanism characterized by an interplay of Ti-Au interdiffusion, Ti migration, gas carrier transport and oxygen gas reaction.
Moreover, we demonstrated that the same method of TiO2 NWs growth can be applied to different type of Ti substrates (Ti foil, Ti thin films, Ti wires), opening new possibilities for different kind of applications.
TiO2 NWs were also modified by doping through ion implantation of Fe+; by tuning the ion implantation energy, NWs showed to change their morphology as a consequence of ion implantation damage by bending like in the case of ion hammering effect reported in literature for Si and Ge nanowires. Further studies of these samples are still on going.
The photocatalytic properties of the TiO2 NWs were assessed by measuring the rate of photocatalytic bleaching of the Methylene Blue dye in aqueous solution via UV spectrophotometry and calculating the photonic efficiency. The sample showed a degradation rate 70% higher compared to the one of a reference TiO2 bulk sample. This is partially due to the measured decrease in reflectivity of the sample in presence of NWs. The photonic efficiency was comparable to the one of the commercial Pilkington-ActiveTM glass, made with TiO2 thin films and applied in many building as self-cleaning glass.
In order to improve the photocatalytic performances of TiO2 NWs, we modified the sample annealing it in forming gas (H2 5% in N2) for 2 hours at 500°C, which was reported to act on the sample defects improving the charge carrier density. The photocatalytic activity of the NWs treated with forming gas, showed to be 3 times higher than that of the reference bulk TiO2 sample (fig.3) while the reflectance was unchanged.
A study of the defects evolution of the NWs was carried out by the very powerful technique of Deep Level Transient Spectroscopy (DLTS) performed at the University of Oslo. First, it allowed identifying in the TiO2 NWs sample, 4 energy levels within the bandgap (at 0.11 eV, 0.30 eV, 0.45 eV and 0.6 eV below the conduction band) never reported before in literature. Second, it revealed that the annealing in forming gas leads to a reduction of deep level recombination centers competing with the photocatalytic processes.
In conclusion, these reported improvements in photocatalytic efficiency indicated the positive contribution of the NW structures, also via the antireflective effect, and the additional positive effect of the forming gas treatment.
Laser synthesis of nanomaterials for water purification
One of the emerging and innovative techniques for water and air purification makes use of photoactive nano-materials. The latter are able to mineralize pollutants and inactivate pathogens bacteria by taking advantage of radical species emission which takes place under materials’ illumination.
A noteworthy application was developed in 2015, namely a “TiO2 based purifying paint” that was used to cover an international airport washroom (at Noi Bai International Airport in Hanoi, Vietnam). However, there is a need for improvement of synthesis techniques of photoactive nano-materials. In fact, among alternative synthesis methodologies for photoactive nano-materials, only a minor part can match the requirements of being industrially compatible, i.e. cheap and scalable, and environment friendly.
Laser irradiation in liquids is a synthesis technology that matches all the above mentioned requirements. For this reason, we focused our attention on its development. In particular, we followed two complementary approaches: synthesis of photoactive nanoparticles in solution and synthesis of a nanostructured surface on a supporting material. These approaches were successfully combined together to realize a highly active device.
Firstly, we synthetized TiO2 nanoparticles in solution by Pulsed Laser Ablation in Liquid (PLAL) which consists of irradiating a titanium foil with a high energy pulsed laser. Particular attention was given to the synthesis and the characterization of the obtained nanoparticles as well as to the analysis of their photocatalytic and antibacterial properties. The synthetized nanoparticles are mainly composed by a mixture of small crystallites and disordered TiO2. Despite their amorphous phase, the nanoparticles showed high photocatalytic and antibacterial activities which are comparable, where not higher, with respect to commercial TiO2 powders, under the same experimental conditions. This unexpected high rate is possibly due to the amount of hydroxyl groups and the presence of the amorphous phase.
The effect of mixing of TiO2 nanoparticles with other nanomaterials was also studied. In order to increase the photoactivity of the TiO2 in the visible range, we synthetized nanocomposites of TiO2 nanoparticles with metals (Ag) or metal oxides (CuO) nanoparticles, both synthetized by PLAL. The nanocomposites gain new interesting properties thanks to a synergic effect of the properties of the respective single materials.
One of the issue of using nanoparticles in solution as a purification system comes from the need of removing the nanoparticles from water after the photocatalytic treatment. In order to solve this issue, another approach can be taken into account: a nanostructured surface can be realized thanks to Laser Irradiation in Liquids (LIL). In fact, we observed that, by irradiating a Ti foil with a high power pulsed laser beam in water environment, a black photocatalytic active coating is formed. We called it “black-TiOx”. The irradiated surface is uniformly covered by cavities of several hundreds nm in diameter with a branched porous nano-structure inside. The latter increases the surface exposed to water, favoring photo-activity. Moreover, photoactivity also benefits from the high absorption in the UV and Visible range. An estimation of the quantum efficiency for UV illumination was obtained by using the approach of the standard ISO10678:2010. We were able to evaluate a quantum efficiency of QEUV=0.011 %.
The photoactivity of this material can be further increased by a factor 4 by using a new approach coming from a combination of the two methodologies previously described, for instance PLAL and LIL. We argued that the relatively low activity (Q.Y.=0.011%) of black-TiOx is related to an inadequate electron transfer to the solution. Thus, an increase of electrons scavenging should bring to an increase of the holes transfer to the solution with a subsequent augmentation of photo-activity. Platinum nanoparticles (PtNps) are well known to favour electrons scavenging thanks to their high affinity with oxygen and their high surface/mass ratio (20 m2/g). On the other side, black-TiOx appears to be metallic and to form an ohmic contact with the underliyng Ti substrate. We prepared PtNps by PLAL and subsequently we positioned these nanoparticles on the rear side of the Ti target. We than irradiated the target to realise the black-TiOx by LIL. The backside position of PtNps allowed us to avoid the formation of a Shottky barrier between TiOx and Pt which would have reduced the efficiency of electrons scavenging. Moreover, this allowed us to avoid the shielding effect of light by Pt nanoparticles. In the end, the deposition of PtNps on the rear side of the black-TiOx sample creates a sandwiched structure called “photochemical diode” with an increased photocatalytic activity. The quantum efficiency displayed by this “photochemical diode” is Q.Y.UV=0.058 %, that is more than twice of what is observed for commercial glasses.
In conclusion, we developed two environment friendly methodologies to synthetize photoactive materials, namely PLAL and LIL. Combining these two methodologies, we were able to manufacture a new and interesting device with a high quantum efficiency that could be used for water purification.
The biological side of the story.
a) Characterization of antibacterial properties of TiO2 and carbon-based nanomaterials.
According to UN regulations, access to clean drinking water is a human right. However, the number of people living in areas without safe drinking water is predicted to heavily increase by the end of this decade. On the other side, disinfection methods currently used in drinking water treatment, as water chlorination, may bring to the formation of harmful disinfection byproducts (DBPs). Alternative disinfection processes including ozonation, advanced filtration processes and germicidal ultraviolet (UV) radiation require expensive chemicals or costly equipment. Thus, there is a need to develop new efficient, low cost and safe methods of purifying water. In the last years, several nanomaterials have been investigated for their possible role in alternative disinfection methods.
Since the first observation of antimicrobial activity of TiO2 made by Matsunaga in 1985, many studies have investigated the disinfection potential of photocatalysis using TiO2 as photocatalysts. According to literature data, highly reactive oxygen species (ROS) are thought to be the key species in the photocatalytic disinfection process, with the hydroxyl radical being the most important oxidant species responsible for the attack of the bacterial cell wall, leading to modifications of membrane permeability and cell death.
All the TiO2 based nanomaterials realized during the WATER project were tested for their antibacterial activity. The Escherichia coli ATCC25922 strain was chosen as a model organism. It has been recently suggested that, for a number of reasons, E. coli appears to provide the best bacterial indication of fecal contamination in drinking water, replacing total coliforms. In addition, the ATCC25922 strain was not genetically modified for molecular biology purposes, hence possible resistance mechanisms were not weakened. Antibacterial activity was evaluated through CFU counts, as a first screening. Wherever interesting results were obtained, bacterial metabolism and possible mechanisms of action were further investigated.
The experiments performed in these years suggested that there is a positive correlation between the extension of nanomaterials surface and the antibacterial activity. Metabolism rate, as measured by MTT Assay, was decreased in parallel: the more active the material, the more lowered the metabolism. The analysis of the mechanism of action suggested that bacterial membrane oxidation takes place in presence of TiO2. Membrane lipid peroxidation level was assessed through measurements of the level of malondialdehyde (MDA), made by the ThioBarbituric Acid Reactive Substances (TBARS) Assay. Exposure of bacteria to laser ablated TiO2 nanoparticles generates a statically significant higher level of MDA, as an example. Moreover, some structures, as nanotubes and nanospikes, display some antibacterial activity even in the absence of UV direct illumination, indicating that some percentage of the antibacterial activity may be due to possible mechanical damage.
Besides TiO2 nanomaterials, carbon-based materials and, in particular, graphene and its derivatives are receiving increasing consideration as they offer the promise to improve existing products and to enable the design of materials and devices with novel functionalities. In our laboratory, graphene oxide (GO) and laser irradiated graphene oxide (iGO) were tested. Best results were obtained with 3 and 4 hours laser irradiation. iGO3 and iGO4 displayed good antibacterial activity and a correspondent decrease in metabolism rate. Analysis of the mechanism of action excluded membrane damage through oxidation. SEM analysis of bacteria, after iGO3 and iGO4 exposure, suggested that mechanical damage is main responsible for the displayed antibacterial activity.
b) Metagenomics: paving the way for marine microbial ecosystem analysis.
The WATER project reads: “Aci Castello, a small town in the Catania area with a protected sea region of EC interest, has been selected as a pilot case to study the effect of nanotechnology applications for water treatment systems. The costal sea is affected during the summer by a contamination with Ostreopsis algae, whose level is definitively higher than normal during the peak of tourism.” [WATER-Grant number 316082- page 8]. The WATER Strategic Research Domain (SRD) task 3 focused on this pilot case. One of the aims of the SRD task 3 was to analyze the state of the sea water in Aci Castello in order to acquire the necessary information about the biological and ecological state of the water. With this goal in mind, a metagenomic study has been performed to evaluate marine microbial communities. Metagenomic approaches based on direct isolation of nucleic acids from environmental samples have proven to be powerful tools for comparing and for exploring the ecology and metabolic profiling of complex environmental microbial communities (Simon C. & Daniel R., 2011).
In the last decade a number of studies demonstrated species–area relationships, biogeography, and spatial patterns at various scales for microbes. Next to this, microbial endemism has been reported as well. (Bodelier, 2011). However, microorganisms change over multiple timescales and in response to different forces, including both biological and non-biological properties of the environment that drive changes in microbial community composition. A great deal can be learned by evaluating the dynamics of community composition and the corresponding environmental parameters (Furhman, 2015).
In our study, thanks to the collaboration with the WATER partner Area Marina Protetta Isole Ciclopi, two sampling sites were selected (Eulerian sampling). One of the sites is close to the sewer (COL sample), while the other is 300mt away from the first, offshore, in an area fully pertaining to the marine protected area (PAN sample). Both the 16S and 18S genes were analyzed in parallel so to get a comprehensive view on both bacterial and microalgae communities. The underlying idea was to understand whether in summer time the anthropogenic pressure may affect communities composition. Thus, two sampling campaigns were performed, at the end of winter time and at the end of summer time. The overall composition of microbial communities shows that the Proteobacteria Phylum was the most abundant, followed by Bacteroidetes. Within the Proteobacteria Phylum, the classes Alpha-, Epsilon- and Gammaproteobacteria were the three most represented. The study revealed that the difference in the communities composition is mainly related to the site of sampling. In fact, the core microbiome was deeply different between sites. The top ten OTUs of each station were exclusive. In the COL sample community, close to the sewer, the most abundant OUT belongs to the Cryomorphaceae family (Class Flavobacteriia, Phylum Bacteroidetes) followed by by the genus Arcobacter (Class Epsilonproteobacteria) and the family Rhodobacteraceae (Class Alphaproteobacteria). The PAN sample community display the typical structure of a marine community comprising Pelagibacteraceae, (Phylum Proteobacteria, Class Alphaproteobacteria) and the Cyanobacteria Phylum. Furthermore, seasonality affects the core structure of the microbiome. Of interest, there is a significant increase in the Bacteroidetes Phylum, especially in the COL sample.
Potential Impact:
The overall impact of the WATER actions can be essentially described in terms of internal and external consequences of our improved research potential:
• The main internal impact is related to the strategic reorganization of our research plan, both in terms of human and technical reinforcement, that will deeply affects the management of available resources. Better exploitation of research facilities, top class participation to H2020 and above all a renewal of an outdated research management with the definitive assessment of a younger and innovative approach to research and social role of scientists. The innovation dimension of this restructuring will go beyond the WATER action, as the reinforcement of human capabilities of strategic vision will be the key issue to start up a more efficient exploitation of our capitalized research resources. This internal impact has not been yet fully achieved, for the resistance of an old mentality of the work environment still anchored to an outdated approach to the research. WATER is trying to affirm a new way of thinking the research, where dissemination can be as important as the scientific publication, or learning the correct methodologies of people management can be an effective expense as that of a new equipment. WATER has shown a balanced approach to all of these issues, but we still need some time to make some part of the work environment understand that such balance is getting closer to Europe than other approaches only based to the scientific competition.
All of these matters were deeply discussed with the independent experts nominated by the EC for the final evaluation, trying to draw a roadmap to put in practice these objectives that is summarized in their evaluation report.
Another positive consequence coming from this action is relative to the capability of attracting external funds. The visibility gained by WATER in fact produced as a result that many potential partners (other CNR Institutes, University of Palermo, University of Catania, some companies) contacted us for future European and national programs, looking at WATER as a reference for the activity on water treatment by nanotechnology. Furthermore, based on the experience we gained, both relative to the submission of the proposal and its evaluation, and to the management of the action, our attitude to the preparation of new proposals is wiser. I can notice the different approach of the WATER team and of other colleagues with respect to drawing a European project, the former being aware of the scheme to follow and of the essential data a proposal has to contain, the latter being more oriented to the scientific matters without taking into the right account also the impact aspects and how they have to be measured. The self evaluation skills improved through the WATER story, probably also thanks to the experience of the coordinator as H2020 evaluator, are resulting crucial in planning new project activities. Of course we are spreading such a more refined approach to writing new proposals also to the external colleagues, so extending the gained know how to the local scientific community, trying to take the best global profit from the WATER experience.
• The external impact can be distinguished in European added value and local added value. From the EU point of view the exploitation of research facilities at EU level and the realignment of research efforts on topics of ERA interest represent the fundamental values to return from the relevant EU investments that have been distributed in Sicily. The enlargement of the capacities for the nano-structure synthesis will significantly improve the scientific and technical infrastructure for this kind of research. Even more than that, potential users of the upgraded facility might be not only the participants of this Action, but also national and international materials science research groups, contributing to a shared increase of the quality of research. CNR Catania will hence become a reference, excellence centre for this kind of synthesis of nanostructures, certainly on a national, but also European level, thanks to the resonance of this action. This is already occurring, with the case of some colleagues from CNRS France asking for making some common experiments by using our ALD system for depositing Ag and Pt on nanostructures synthesized in their Institute to be applied to Atomic Force Microscopy. Furthermore, our affirmation in the field of nanotechnology caused that a member of our CNR Unit has been appointed as the head of the research area “Functional nanomaterials” in the recent reorganization of the entire CNR Institute. Specifically, we have supported for this position a colleague not directly involved in WATER, because we want to extend the impact of the action as broad as possible, without restricting the positive return to a group of “privileged” people.
The public and private local initiatives suffer of a lack of organization that has been supported by the WATER actions about its specific domains. Moreover, the strong action of WATER dissemination specifically addressed to cover the gap between science and society will have a long term impact by creating a general thrust into scientific resources to drive the economical development of a country. The local impact of the WATER dissemination actions is contributing to build a new image of science in today’s life and to improve the visibility of local scientific research centers. Local authorities and SMEs looked at WATER ideas with growing enthusiasm and positive participation that can spread around and inflame a renascent general mobilization. It is remarkable that a worldwide leader in water filtration system, ATLAS Filtri, decided to support WATER with the perspective to implement new research initiatives, and that local SME (Fonte Nuova, Plastica Alfa) have signed a MoU with CNR for exchanging ideas and put in practice a technological transfer. . We want to pursue a stronger cooperation between academia and business via staff exchange, that might turn creative ideas into innovative products and processes to address European and global societal challenges.
The action wants to strengthen research and business performances and promote innovation and knowledge transfer throughout the EC support. Stronger cooperation between universities and business via staff exchange will encourage entrepreneurship and help to turn creative ideas into innovative products and processes that can efficiently address European and global societal challenges.
In general, we can claim that the research strategy decided when the proposal was drawn up, i.e. the reinforcement of our skills in the area of nanotechnology, for innovative applications to the mammoth problem of water for the humanity, had an impact in terms of i) scientific production, ii) visibility both to the professionals and the broad public, iii) cultural growth of the team, iv) relationship with SME.
Concerning the projection of our initiative to a broader field of applications, WATER represents a bridge – for the first time in a European high tech context – between local authorities, SMEs (New Ecotecnica Sud, etc.) and world leader industry in the filters technology (ATLAS Filtri). All of these interactions, and the consequent achievements we expect, would not exist without the human and technical reinforcement guaranteed by this action.
We made a significant effort to stimulate a two-way dialogue with the general public that will influence decisions concerning scientific and environmental policies and will be crucial for long-term development of nanotechnology in Catania. The dissemination initiatives we propose are definitively innovative for our scientific environment, also at European level, and aim to a general cultural growth.
In general, we can claim that the research strategy decided when the proposal was drawn up, i.e. the reinforcement of our skills in the area of nanotechnology for innovative applications to the mammoth problem of water for the humanity, had an impact in terms of i) scientific production (28 JCR publications), ii) visibility both to the professionals and the broad public (20 presentations at international conferences, 4 awards, independent mentions on the media) iii) cultural growth of the team (attendance to top level courses on management and communication), iv) relationship with SME (two MoU signed, two companies among the partners).
In 2004 the European Commission published its strategy for Nanotechnology, one of five key dynamics identified is the need to “integrate the societal dimension”. It argues that ethical principles must be respected and that public dialogue can be an important contributor to developing socially beneficial nanotechnologies. Without a serious communication effort, nanotechnology innovations could face an unjust negative public reception. An effective two-way dialogue is indispensable, whereby the general publics’ views are taken into account and may be seen to influence decisions concerning R&D policy. The public trust and acceptance of nanotechnology will be crucial for its long-term development and allow us to profit from its potential benefits. It is evident that the scientific community will have to improve its communication skills.[Communication from the Commission – Towards a European strategy for nanotechnology, 2004]. With this aim, communication skills were potentiated as complementary skills for researchers with special trainings (WP2) and particular attention was paid in the formulation of messages to be disseminated (WP 4). The only way to avoid useless waste of resources (money and personnel time) is starting to operate with technicians of communication. In this sense, this approach is new for this community and it represents a fundamental innovation of the WATER action in our local professional environment. This new approach about transversal visibility produced its results: from the professional point of view we recruited PhD and Master students from other Scientific areas (biology, chemistry), but also the potentiality of new media channels, like Facebook, has been exploited with the result of a large public renovated interest in local science events.
Local authorities and SMEs have been attracted by our broad range promotion events looking at the immediate advantages of self publicity, with a consequent interest in science and in the CNR activities. Through focused activities of WP2 about the research domain addressed by WATER, the local authorities and SMEs were involved in research tasks. This realized a missed link among CNR and local stakeholders.
WATER applied for the organization of the IEEE (Institute of Electrical and Electronics Engineers) NMDC (Nanotechnology Materials and Devices Conference) on May 2013. On October 2013 the President of the IEEE Nanotechnology Council, Prof. Stephen Goodnick, committed the organization of the IEEE-NMDC 2014 to the CNR-Catania.
The IEEE-NMDC 2014 (http://www.ieee-nmdc2014.org/) was the 9th edition in an international series. It was hosted for the first time in Europe, Sicily, Aci Castello (Italy), in Grand Hotel Baia Verde (http://www.baiaverde.it/EN/) on October 12-15, 2014.
The conference was a forum of discussion about nanotechnology, with a special focus on materials and devices. The main objective of the conference was to gather leading edge scientists in the field of nanotechnology to review the most recent highlights, spread over several applications area.
The scientific program included plenary sessions (one a day), two parallel oral sessions, a poster session and an exhibition of the sponsors (the WATER project was the premier sponsor of the conference). In detail, the conference had 3 plenary speakers, 15 invited speakers, 73 oral presentations, 50 poster presentations, 10 sponsors. Moreover, three oral sessions and one session of the posters were focused on “Nanostructures for water purification”, that is the subject of the WATER project. All the presentations were high-level presentations, followed by constructive and lively debates. The poster session was made up of high-level posters with a lot of scientific debates.The three best oral presentations by young scientists and the three best posters were awarded during the closing session.
During the conference an event dedicated to Ph.D. students and young scientists was organized: “Lunch with Prof”. Young scientists had the opportunity to have the lunch (one a day) with the plenary speakers: sitting around a table, enjoying the Italian cuisine, the students shared with outstanding scientists ideas, curiosities and experiences.
Scientists from research centers, universities and industries, from all over the world (30 different countries), attended the conference. In total the number of participants was 207.
A video of the congress has been commissioned to an advertising agency, so to give visibility to the CNR-Catania and to the WATER project.
“Congratulations on a very nice conference, the attendance was better than expected, the scientific and social programs were very well organized, congratulations on a very successful conference” wrote Prof. Stephen Goodnick, Past President of the IEEE Nanotechnology Council.
On January 2014, a proposal was submitted for the organization of a symposium at the 2015 E-MRS (European-Materials Research Society) Spring Meeting as principal organizer. The E-MRS Spring Meeting is the largest material forum in Europe. The proposed symposium was entitled: “Materials for applications in water treatment and water splitting”.
On April 2014, the symposium was accepted as symposium B of the 2015 E-MRS Spring Meeting (http://www.emrs-strasbourg.com/index.php?option=com_content&task=view&id=800&Itemid=1652). The meeting was held at the Congress Center (Grand Palais) in Lille (France), on May 11-15, 2015. The congress included 32 parallel symposia, one plenary session and one exhibition session, with more than 3000 attendees.
The symposium B was focused on materials science, processes and device issues for future efficient water applications, with the main aim of attracting, for the first time at the E-MRS meeting, experienced researchers in the field of advanced materials for water purification and hydrogen production by water splitting, so to encourage the cohesion of these communities.
The symposium was sponsored by the project WATER and by ATLAS Filtri company, partner of WATER.
The symposium received 165 abstract, and since the abstract exceeded 100 it was considered a large symposium.
Scientists from research centers and universities, from all over the world (36 different countries), attended the symposium B.
In detail, the symposium had 12 invited speakers, 68 oral presentations, and 72 poster presentations.
The symposium had 12 oral sessions and 2 poster sessions. All the presentations were high-level presentations, followed by constructive and lively debates. The poster session was made up of high-level posters with a lot of scientific debates.
The 2 Graduate Student Award winners of the symposium, selected by a commission formed by the symposium organizers and two members of the scientific committee, were honored during the plenary session by the E-MRS. In addition, thanks to the support of the sponsors (WATER and ATLAS Filtri), 6 best posters were awarded during the closing session of the symposium.
The proceedings will be published by the Elsevier in a special issue of “Materials Science in Semiconductor and Processing” next December.
An advertising campaign has been developed to inform the general public about the WATER action. We communicated with the society by means of advertisements on: newspapers and magazines (both printed and on-line), radio, and TV. The advertisement campaign has been designed thanks to the support of an advertising agency (Boomerang adv, www.boomerangadv.com).
The commercial is available through the WATER web-site (www.water.imm.cnr.it) on the home page.
The slogan is always the same: “So that our children will not be in bad water”.
The advertisement appeared on broad-audience newspapers. In the following is listed the newspapers and the days of publications:
La Repubblica (March 22nd, 2014; March 28th, 2015)
Il Sole 24 Ore (March 21st, 2014; March 27th, 2015)
La Repubblica Regional (Sicilian) Edition (March 18th, 2014; March 24th, 2015)
Il Sole 24 Ore Web (March from 17th to 23rd, 2014; March from 23rd to 29th, 2015)
The advertisement appeared on broad-audience magazines. In the following is listed the magazines and the days of publications:
L’Espresso (weekly) (May 30th, 2014; June 15th, 2015)
Focus (monthly) (June, 2014; June, 2015)
The radio advertisement went on the air on national networks as reported below:
Radio 1, Radio 2, and Radio 3 (from January19th to 26th, 2014 for a total of 21 passages)
Radio 1, Radio 2, and Radio 3 (from January25th to 31st, 2015 for a total of 21 passages)
A commercial went on national and satellite TV as reported below:
TGCOM 24, Iris, Rete 4, Canale 5 (from December 15th to 29th, 2013, for a total of 49 appearances)
Sky, National Geographic (from September 21st to 28th, 2014 for a total of 70 appearances)
Sky, Discovery Channel, Discovery Science (from July 6th to 12th, 2015 for a total of 138 appearences)
A clear consequence of the advertising campaign was a lot of independent articles, both printed and no-line, focused on the WATER action (for major information click on:
http://www.water.imm.cnr.it/index.php?option=com_content&view=article&id=85&Itemid=451&lang=en
http://www.water.imm.cnr.it/index.php?option=com_content&view=article&id=86&Itemid=460&lang=en). These significantly increased the visibility of the CNR-Catania at regional and national level.
The CNR group participated during the WATER action to several conferences in order to disseminate its scientific results. Some examples relative are reported in the following.
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: Annual International Eurodoc Conference Place: Budapest, Hungary
Location: Budapest, Hungary
Date: March 25-29, 2014
Type of presentation: Invited talk
The conference titled: “The position of Early Stage Researchers in ERA & EHEA. How to face the challenges ahead?” More than 100 participants from all across Europe gathered in Budapest, Hungary, to discuss the challenges that Early Stage Researchers (ESRs) face in the European Research Area (ERA) and in the European Higher Education Area (EHEA). One of the most relevant topics discussed during the three days of this event was the professional development that doctoral candidates and Post-Doctoral researchers need in a challenging scientific environment.
Maria Antonietta Buccheri took part to the conference as an invited speaker for the Plenary session I: “Where we stand- the position of ESRs in ERA.”. She reported Marie Curie Fellows’ views and experiences on the subject, both acknowledging progresses made in recent years and addressing key issues to be afforded in order to make researchers’ careers in Europe more attractive.
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: Euroscience Open Forum 2014 (ESOF2014).
Location: Copenhagen, Denmark
Date: January 20-26, 2014
Type of presentation: Organization of a session
Maria Antonietta Buccheri organized a session in the frame of the “Career programme” dedicated to researchers careers: “Researchers’ careers in Europe: looking for the Ariadne thread in the MCFA world café”.
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: LET’S 2014
Location: Bologna, Italy
Date: September 29 - October 1, 2014
Type of presentation: Poster presentation, B2B meetings
“Facing WATER challenges through nanotechnologies.”
LET’S 2014 (Leading Enabling Technologies for Societal challenges) is an international Conference organized in the context of the Italian Presidency of the Council of the European Union, with the Patronage of the Ministry of Education, University and Research, the Ministry of Economic Development and the Ministry of Foreign Affairs, and supported by European Union Funding for Research and Innovation.
During the conference, the poster presented by Maria Antonietta Buccheri attracted some interest and she was interviewed by TRIWU’, a web tv dedicated to innovation and transfer of knowledge. Interview can be found at the following link: http://www.triwu.it/categorie/-/asset_publisher/Fm8O/content/filtri-nanotecnologici-per-la-depurazione-dell%E2%80%99acqua?p_r_p_564233524_categoryId=10679
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: 101st International VLB October Convention
Location: Berlin, Germany
Date: September 28-29, 2014
Type of presentation: Invited talk
“Applications of nanotechnology to water treatment: the European project WATER”
The Research Institute for Water and Waste Water Technology (FIWAT) at the Versuchs- und Lehranstalt für Braurei in Berlin (VLB) is one of the partners of the WATER project. Fruitful links have been developed with the Institute. The opening session was focused on “Nano and micro particles in complex liquids”. Maria Antonietta Buccheri was invited to take part to the session, where she highlighted the WATER project and shed light on possible applications of nanotechnologies to water treatment.
• Person: Ruy Gonzalez and Giuliana Impellizzeri, CNR Researchers
Event: Visit and Beam time at the Centre for Micro Analysis of Materials (CMAM) of the Universidad Autónoma de Madrid
Location: Madrid, Spain
Date: February 13-19, 2014
Type of presentation: Seminar
“Ion Beam modified TiO2 for advanced water purification in the frame of WATER project”
• Person: Vittorio Privitera, CNR Senior Resercher
Event: Ettore Majorana Foundation and Centre for Scientific Culture, ERICE. International School "Materials for Renewable Energy" 2014. Chaired by David Cahen (Weizmann Institute of Science, Rehovot, Israel), David Ginley (NREL, Golden, Colorado USA), John Poate (Colorado School of Mines, Golden, Colorado USA), Abdelilah Slaoui (InESS-CNRS, Strasbourg, France), Antonio Terrasi (Dept.of Phys. and Astr., University of Catania, Catania, Italy)
Location: Erice, Italy
Date: July 12-18, 2014
Type of presentation: Lecture
Presentation of the European Project “Water”
• Person: Lucia Romano, Researcher at the University
Event: ICONN 2014 (International Conference on Nanoscale and Nanotechnology) and ACMM23 (23rd Australian Conference on Microscopy and Microanalysis)
Location: Adelaide, Australia
Date: February 2-6, 2014
Type of presentation: Invited talk
“Semiconductor metal oxides nanostructures for water applications”.
• Person: Lucia Romano, Researcher at the University
Event: E-MRS Spring Meeting 2014 (http://www.european-mrs.com/)
Symposium E: Defect-induced effects in nanomaterials
Location: Lille, France
Date: May 25-30, 2014
Type of presentation: Oral and poster presentations
1) Oral presentation
“Swift heavy ion beam modification of rutile TiO2 for photo-catalysis applications”
2) Poster presentation
“Fe-ion implantation induced defects in TiO2 thin films”
3) Speech, during the Plenary Session, focused on the description of the activity “Nanergame”, developed in the framework of the WATER project, that received the “Reach.Out!” competition award
• Person: Maria Antonietta Buccheri, CNR Researcher
Event: Workshop “Researchers’ careers: does Theseus need a new thread across the labyrinth?” Organised by the Marie Curie Fellows Association (MCFA)
Location: London, UK
Date: February 28 - March 1, 2015
Type of presentation: Workshop Co-organiser & Speaker.
• Person: Giuliana Impellizzeri, CNR Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Location: Lille, France
Date: May 11-15, 2015
Type of presentation: Opening of Symposium B (as the Principal Organizer of the Symposium)
• Person: Giuliana Impellizzeri, CNR Researcher
Event: Energy Materials Nanotechnology (EMN) Cancun Meeting 2015
Location: Cancun, Mexico
Date: June 8-11, 2015
Type of presentation: Invited talk
“TiO2 nanomaterials: synthesis, properties, modifications, and photocatalytic applications”
• Person: Vittorio Privitera, CNR Senior Researcher
Event: Campus Colloquia Series
Location: Bologna, Italy
Date: April 22, 2015
Type of presentation: Invited lecture
“Nanotechnology for water purification: the European project WATER”
• Person: Vittorio Privitera, CNR Senior Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Location: Lille, France
Date: May 10-15, 2015
He was a Member of the International Scientific Committee of Symposium B; Chair of Poster Session I - Materials for Environment; a Member of the Commission for the Best Student Award.
He was co-author of 10 oral and poster presentations.
• Person: Vittorio Privitera, CNR Senior Researcher
Event: MiNaB-ICT – International Workshop on “Micro-Nano-Bio-ICT Convergence”, Current Research and Future Trends (http://minabict.fbk.eu/)
Location: Otranto (Lecce), Italy
Date: July 13-15, 2015
Type of presentation: Invited talk
“TiO2 and C-based photocatalytic nanomaterials for water purification”
• Person: Vittorio Privitera, CNR Senior Researcher
Event: Italian National Conference on Condensed Matter Physics (FISMAT 2015)
Location: Palermo, Italy
Date: September 28 – October 2, 2015
Type of presentation: Invited talk
“TiO2 based photocatalytic nanomaterials for water purification”
• Person: Lucia Romano, Research at the University
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Place: Lille, France
Date: May 10-15, 2015
She was a Member of the International Scientific Committee of Symposium B; Chair-person of the Session “TiO2 for water splitting I” of Symposium B; Member of the Poster awards committee of Symposium B.
She was co-author of the following presentations:
• Person: Ruy Sanz Gonzales, CNR Researcher
Event: MRS Spring Meeting 2015
Location: San Francisco, USA
Date: April 6-10, 2015
Type of presentation: Oral and poster presentations
Oral presentation to Symposium UU
“Antireflective Rutile TiO2 Nanospikes Showing Enhanced Photo-Activity”
• Person: Ruy Sanz Gonzales, CNR Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Location: Lille, France
Date: May 11-15, 2015
Type of presentation: Oral and poster presentation
1) Oral presentation to Symposium W
“Response of aortic vascular smooth muscle cells, human mesenchymal stem cells and E-coli to rutile TiO2 flat and nanospikes surfaces”
2) Poster presentation to Symposium B
“Photoactivity of TiO2 and Au decorated TiO2 nanotubes for application in water purification”
• Person: Ruy Sanz Gonzales, CNR Researcher
Event: Visit to the Instituto de Microelectrónica de Madrid
Location: Madrid, Spain
Date: September 30, 2015
Type of presentation: Seminar
“TiO2 nanostructures in the frame of WATER Project“
• Person: Viviana Scuderi, CNR Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Location: Lille, France
Date: May 11-15, 2015
Type of presentation: Oral presentation
“TiO2 nanoplumes for efficient photocatalysis under UV-VIS light”
• Person: Massimo Zimbone, CNR Researcher
Event: E-MRS Spring Meeting 2015 (http://www.european-mrs.com/)
Symposium B: Materials for applications in water treatment and water splitting
Location: Lille, France
Date: May 11-14, 2015
Type of presentation: Oral presentation
“Effect of calcination temperature on the photo-catalytic and antibacterial activity of TiO2 nanoparticles obtained by pulsed laser ablation in liquids”
WATER organized and participated to roundtables, B2B meetings and events with SMEs and industries in order to increase the interaction between the CNR group and the industrial world. The dialogue was established not only with companies supporting the WATER action (i.e. Atlas Filtri and New Ecotecnica Sud), but also with other national and international companies. These interactions can be helpful for the sustainability of the present action beyond its lifetime.
Europe 2020 strategy for growth, reaching the southern Italy market and its key players.
B2B Networking event – Business, Technological and Research Partnership in Sicily and Italy.
https://www.b2match.eu/m4g-italy-sicily
Location: Palermo, Italy
Date: March 27-28, 2014
The aim of this event was to promote business, technological and research partnerships between Italian, especially Sicilian, and European/non-European companies, universities, research centers, technological institutes in active sectors identified as key contributors to achieving growth in southern Italy.
The event was organized with the support of the Enterprise Europe Network and Regione Sicilia.
This B2B event aimed to initiate R&D, technological and commercial cooperation in the following sectors: agro food; bio-agro food; maritime industry and fishing; intelligent energy; tourism and cultural heritage; handicrafts; textiles, clothing and fashion; biotechnology & biomedical; ICTs; construction & green building; creative industry; others. Moreover, face to face meetings between European and Italian companies gave the opportunity of: targeting potential business partners; reaching the Italian market and its key players; examining business and investment opportunities in Sicily; establishing cross-border contacts and partnership; exploring opportunities of research cooperation also in the framework of Horizon 2020 programme.
Meetings with Plastica Alfa
Location: Caltagirone (Catania), Italy
Date: May 6, 2015
A roundtable was held at the headquarter of Plastica Alfa (http://www.plasticalfa.com/index.php/en/) a Sicilian SME also experienced in water filtration systems. The CNR group visited the production site.
In order to formalize the collaboration between the project WATER and Plastica Alfa a Memorandum of Understanding was signed.
Locations: Catania, Italy
Date: May 27, 2015
A second meeting with Plastica Alfa was organized at the CNR Unit at the Department of Physics in order to discuss about future scientific interactions and funding possibilities. During the meeting the WATER team gave the following presentations:
- Efficient photocatalysis polymeric nanocomposites for water purification, Maria Cantarella
- Membrane technology for water purification, Simona Filice
- Carbon nanotube- and graphene-based materials for water purification, Daniele D’Angelo
The members of Plastica Alfa also visited the laboratories of the CNR group.
In terms of exploitation of the project results, a MoU was signed with Plastica Alfa as a result of our meetings and we are agreeing on the signature of a research contract for CNR.
In general, the WATER action aimed to boost the scientific and technological research potential of CNR in the emerging research area of water treatment. New specific research lines about nanotechnology applications for water treatment were opened, thanks to the strong background of the CNR researchers in materials science and nanotechnology, thanks to the upgrading of the existing facilities with new research infrastructures, and thanks to the strong collaboration with the partners of the WATER project. Two main research lines were established. The first one is based on metallic oxide nanostructures for water treatment. TiO2, ZnO and CuxO nanostructures show relevant properties of photocatalytic degradation of water pollutants. Several forms of nanostructures (thin films, nanoparticles, nanowires, nanotubes, etc.), possibly coupled with metals, are synthesized with the main aim of improving the efficiency of the materials in water disinfection and purification. The second research line is focused on carbon-based materials for water treatment. Carbon-based materials can be fruitfully applied for water treatment. Carbon nanotubes, acting as nanoporous adsorbents, work effectively against chemical and biological contaminants. They can be also used to enhance the photocatalytic properties of TiO2 nanostructures. Graphene and graphene oxide have also a great potential for water filtration.
The conclusive event of the project celebrated science and water in the Castello Square in Aci Castello, on October 3rd, 2015, just at the beginning of the last evaluation semester. The festival was called “Water Day”.
The main aim of this action was to attract SMEs, industries, research organizations, but also the general public, policy makers, and Media towards the topics of WATER. For this reason, the Water Day was publicized through an intense advertising campaign. The advertisement campaign was designed and planned thanks to the support of our advertising agency (Boomerang adv, www.boomerangadv.com) in a coherent style with the WATER campaign on newspapers and magazines (both printed and on-line), radio, and TV, developed during the last three years (from 2013 to 2015). We put up 210 billboards, for two weeks, in Catania, Aci Castello, Aci Trezza, Acireale, and Etna villages.
An advertisement also appeared in the most widespread newspaper in Sicily “La Sicilia” for two days. We promoted the Water Day through the social channels (facebook and twitter) and the web-site of the WATER project. Finally, we advertize the event in several SMEs and in primary and secondary schools in the Ionian coast of Sicily.
Six exhibitors participated to the event: the project WATER (with a stand showing posters and nanostructured materials synthesized during the last three years), the Municipality of Aci Castello that also patronized the event, the Marine Protected Area of the Cyclops Islands, Atlas Filtri, New Ecotecnica Sud, and Fonte Nuova (local company experienced in the distribution of filtered and purified water, that signed a memorandum of understanding with the WATER consortium). The project WATER also organized a stand for kids with experiments, games, and gifts. A catering and many gadgets gladdened the local community. In the following the program of the event is reported.
The Norman Castle of Aci Castello simultaneously hosted a meeting focused on the “Future of water resources in the Mediterranean countries”, with the participation of the Mayor and the Heritage Councellor of Aci Castello and the Spanish governor of the region of Almeria. This institutional event was the occasion to spread the results of the project WATER and promote the visibility of the CNR-Catania at European level. In particular, the region of Almeria has a pilot plant for the decontamination and disinfection of water by solar photocatalysis (mechanism that has been extensively studied by the WATER consortium during these three last years). In the following the program of the institutional event is reported.
More than one thousand people attended the Water Day, well beyond our expectation. The event was also attended by the European partners of the project, from France, Germany, Norway and Spain, and by the Members of the Advisory Board, from USA and Australia.
The Water Day strongly attracted the Media, as demonstrated by the presence of several local TV channels and by articles published in on-line journals and also in “La Sicilia” newspaper (on October 4th, 2015).
A video of the event has been commissioned to our advertising agency, so to give visibility to the CNR-Catania and to the WATER project.
The Water Day was an important occasion for the CNR group to strength its link with the general public, policy makers, Media, SMEs and other research organizations.
The overall actions in terms of dissemination strategy and human resources valorization represented indeed the development of the exploitation plan of WATER. Our target was to establish industrial and commercial links, so contributing to the economic development of our region. Some SMEs and companies, supported by signing MOU documents, are taking advantages of the WATER research, within the framework of our IP and research strategy. We organized and participated to many events and workshops addressed to enterprises with the aim to stimulate the interest of industries converting our research results into saleable products, so to reach the goal to commercialize our research findings. The involvement of local authorities contributed to address the research outcomes towards the care for the environment by producing in a long term vision direct benefits on the tourism and a better exploitation of local resources. The achievement of a high capability of research management and of strategic vision is a fundamental result for the economic and social outcomes of our research potential. The latter was exploited through a human and technical reinforcement path, bringing to a more significant involvement in the European collaborative research and in a more productive activity of the applicant, that attracted bright researchers and improved the research network at national and international level. Instead, the top management capabilities were the key to change the mentality of the research group, from a daily problem solving approach to a methodology of long term vision and strategy. Furthermore – based on the knowledge acquired thanks to the exchanges, the courses, the seminars, the contacts with the local authorities and SME, the external evaluation – the action produced the establishment of practices and procedures for capacity building, quality improving and highly specialized training. We exploited such “protocols” by sharing them with the local scientific entities and putting our competence in these fields at the service of our Institute.
List of Websites:
www.water.imm.cnr.it
