Photocatalytic decomposition of formic acid in aqueous solution using Cr-doped Bi_(12)TiO_(20) catalyst under visible light irradiation

摘要

Undoped and Cr-doped Bi_(12)TiO_(20) (BTO) photocatalysts were prepared and the effects of the dopants on the light absorption and the photocatalytic activity of BTO in visible light were investigated. The light absorption edge of BTO extends to visible region, and the doping of BTO with very low concentration (7.0×l0~(-4) wt%) of Cr leads to further shift towards longer wavelength. The doping also decreases the recombination rate of photo-generated electrons and holes in BTO photocatalyst. The Cr-doped BTO showed higher photocatalytic activity for the degradation of formic acid in visible light as compared with undoped BTO. The enhanced photocatalytic activity of Cr-doped BTO are mainly due to their small band gap and low recombination rate of photo-generated electrons and holes.