Mechanochemical preparation of sulfur-doped nanosized TiO2 and its photocatalytic activity under visible light

In order to make nanosized TiO2 photocatalyst responsive to visible light and effectively utilize solar energy, we have, for the first time, prepared S-doped nanosized TiO2 by a mechanochemical method with hydrolysis of TiCl4. The as-prepared S-doped nanosized TiO2 possesses strong ab-sorption for visible light of 400―650 nm and shows high photocatalytic activity for decomposition of methylene blue under irradiation of visible light. The oxidation states of the S atoms incorporated into TiO2 were determined to be S6+ and S4+. The comparative study of fluorescence emission spectra shows that S-doping has also improved the separa-tion of electron-hole pairs.