Preparation of Titanium-Silicon BInary Oxide Thin Film Photocatalysts by an Ionized Cluster Beam Deposition Method. Their Photocatalytic Activity and Photoinduced Super-Hydrophilicity

摘要

Titanium-silicon binary oxide thin films of differing TiO_2 content were prepared by using an ionized cluster beam (ICB) deposition method using multi-ion sources under a dry preparation process. From the results of UV-vis absorption measurements, binary oxide thin films with low TiO_2 content showed much higher transmittance as compared with the pure TiO_2 thin film, indicating that the Ti-oxide species of these Ti-Si binary oxide thin films exist in a highly dispersed state within the SiO_2 matrices. Ti K-edge XAFS measurements revealed that such binary oxide thin films with low TiO_2 content (less than 20%) showed only a sharp preedge peak attributed to the highly dispersed Ti-oxide species which are different from the peaks of anatase TiO_2 thin films. Moreover, they were found to exhibit much higher and more efficient photocatalytic reactivity for the decomposition of NO into N_2 and O_2 under UV light irradiation than the pure TiO_2 thin films.