Bifunctional TiO2 Catalysts for Efficient Cr（VI） Photoreduction Under Solar Light Irradiation Without Addition of Acids

Bifunctional TiO2 photocatalysts co-doped with nitrogen and sulfur were prepared by the controlled thermal decomposition of ammonium titanyl sulfate precursor. They have both photocatalytic activity and Brφnsted acidity, and thus are active in the photoreduction of Cr（VI） under solar light irradiation without the addition of acids. The activity is superior to that of Degussa P25 in the acidified suspension at the same pH adjusted by H2SO4.