INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
congresos y reuniones científicas
New UV-transparent polymeric supports for tio2 photocatalysis
PORTELA R.; CANDAL R.J.; CORONADO J.; SANCHEZ B.
Pittsburgh, PA, EE.UU
Congreso; 11th Internacional Conference on TiO2 Photocatalysis: Fundamentals and Aplications; 2006
Selection of supports for TiO2 photocatalysis is not a trivial task. The support should be resistant to oxidant environments and the photocatalyst must be strongly adhered to its surface. In the treatment of gas streams, where pellets or powders need to be removed or kept fluidized, supported TiO2 is commonly used. Unfortunately, coating the inner reactor wall with the photocatalyst does not provide an efficient TiO2/pollutant contact, so more complicated systems must be developed. To improve the pollutant/photocatalyst interaction, an attractive possibility is to fill the reactor with TiO2 deposited on a transparent support. In such a way, the use of UV-radiation can be optimized by shading reduction. When borosilicate Raschig rings are used as support, a common problem is the pressure drop produced in the reactor as consequence of the filler. The extent of this problem can be reduced by the use of monolithic structures as support. UV-transparent polymers -cheap, lightweight and easily shaped in a variety of geometries- combine several advantages, allowing irradiation in perpendicular direction to the gas flow; consequently, the preparation of inorganic thin films on organic supports is currently attracting a significant attention. The TiO2-coating of plastic substrates presents several difficulties: the film adhesion is usually poor and well crystallized TiO2 particles -required to optimize the photocatalytic performance- are usually obtained at high treatment temperatures, not compatible with thermally sensitive substrates [1,2]; on the other hand, photo-oxidation of the polymeric support must be avoided, because it could reduce the transparency and the mechanical resistance of these materials . In this work, we extend our previous studies  to develop more efficient procedures of coating UV-transparent polymeric monoliths with TiO2. The resultant photocatalysts have been characterized and the results show that nanocrystalline anatase can be obtained at low temperatures and adhered onto the surface of these materials, performing good photocatalytic performance in TCE and H2S destruction in gas phase. The aging of the coated polymers by water condensation and UV-irradiation and the possibility of regeneration with water of the deactivated photocatalysts after H2S treatment have also been studied. References  M. Langlet, A. Kim, M. Audier, C. Guillard and J.M. Herrmann, J. Mater. Sci., 38 (2003) 394  H. Strohm, M. Sgraja, J. Bertling and P. Löbmann, J. Mater. Sci., 38 (2003) 1605  J. Shang, M. Chai, Y.F. Zhu, Environ. Sci. Tech., 37 (2003) 4494  B. Sánchez, J.M. Coronado, R. Candal, R. Portela, I. Tejedor, M.A. Anderson, D. Tompkins and T. Lee. Appl. Catal. B. Presentación Oral