Design of polyoxometallate-titania composite film (H3PW12O40/TiO2) for the degradation of an aqueous dye Rhodamine B under the simulated sunlight irradiation

A series of polyoxometallate/titania (H3PW12O40/TiO2) composite films with different H3PW12O40 loadings (6.3%, 7.7%, 14.7% and 16.7%) were prepared by a modified sol-gel-hydrothermal route followed by a spin-coating method. The smooth films are constructed by the well-distributed H3PW12O40/TiO2 sphere with particle size in the range from 80 to 100 nm, and the bandgap of the composite films is somewhat narrower compared with as-prepared pure TiO2 film. As a novel photocatalytic material, the photocatalytic performances of the H3PW12O40/TiO2 composite films were evaluated by the degradation and mineralization of an aqueous dye Rhodamine B (RB) under solar simulating Xe lamp irradiation (320 nm < lambda <780 nm), and the enhanced photocatalytic activity in comparison to pure TiO2 film as well as the H3PW12O40/TiO2 and Degussa P25 TiO2 powder was obtained. Additionally, the composite films can be reused at least for three times without losing their catalytic activity. (C) 2011 Elsevier B.V. All rights reserved.