Description succincte
(Anglais)
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This project aims at preparation, testing and characterization of materials with improved photoactivity in the visible compared to known materials. The most promising candidates are N- and/or S-doped TiO2 nanoparticles and novel Bi2O3-based materials. Synthesis of the materials will be conducted via two routes : wet chemistry (sol-gel and powder based) and high temperature synthesis (hot wall and flame). The powders will be deposited onto a) glass flat surfaces, b) Raschig rings, c) cotton textile surfaces and d) wall panels by different methods. The evaluation of the photoactivity under visible light will be carried out following the inactivation of E coli K-12. The self-cleaning effects will be followed by the discoloration kinetics of lycopene/carotenoid stains of wine/coffee by DRS measurements and the evolution of CO2 from the stain during the discoloration process by GC. The doped TiO2 powders will be characterized by: TEM, DRS, Infrared spectroscopy, BET area, XPS-spectroscopy, Raman sperctroscopy and X-ray diffraction to clear the origin of the visible light enhancement in the doped samples. The results obtained will be compared to the photoactivity observed with Degussa P25 powders under visible light, which is the reference material in photocatalysis.
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Partenaires et organisations internationales
(Anglais)
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AT, BE, BG, CH, CZ, DE, DK, ES, FI, FR, GR, HU, IE, IT, PL, PT, RO, RS, SI, UK
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Résumé des résultats (Abstract)
(Anglais)
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TiO2 photocatalysis for the removal of pollutants in both air and water has been investigated during the past 20 years. Although promising results and large scale application devices have been developed in both environment cleaning and medical hygiene applications, high energy UV light is required to apply this process. Use of visible light would enable higher efficiencies in open-field solar technologies and also to implement new applications under artificial lighting inside bulidings. Extensive research is carried out to modify the intrinsic properties of TiO2 by e.g., doping. Our approach is to search new materials based on mixed metal oxides with similar behavior as that of TiO2 but with an increased efficient activity under visible light. The project includes the fabrication of nanoparticles of such metal oxides; their comprehensive characterization to define their physicochemical properties; and their evaluation as a photocatalyst to degrade model organic pollutants in water and air, as well as their bactericidal activity. A strong effort will be additionally furnished to understand and interprete from a fundamental scientific point of view the observed phenomena. Finally, the impact of the introduction of such new technology on human health and on the environment will be assessed.
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