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 (H(3)PW(12)O(40)/TiO(2)) composite films with different H(3)PW(12)O(40) 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 H(3)PW(12)O(40)/TiO(2) 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 TiO(2) film. As a novel photocatalytic material, the photocatalytic performances of the H(3)PW(12)O(40)/TiO(2) composite films were evaluated by the degradation and mineralization of an aqueous dye Rhodamine B (RB) under solar simulating Xe lamp irradiation (320 nm<λ<780 nm), and the enhanced photocatalytic activity in comparison to pure TiO(2) film as well as the H(3)PW(12)O(40)/TiO(2) and Degussa P25 TiO(2) powder was obtained. Additionally, the composite films can be reused at least for three times without losing their catalytic activity.