Preparation of S, C cation-codoped SrTiO3 and its photocatalytic activity under visible light

S, C cation-codoped strontium titanium dioxide (SrTiO3) was synthesized by calcination of a mixture of thiourea and SrTiO3 powders in a lidded crucible. After C and S ions were doped into SrTiO3, the absorption edge of SrTiO3 powder was greatly shifted from 400 to 700 nm. The obtained powder was found by XPS, XRD and FIF-IR to have a perovskite structure in which C and S atoms were incorporated into SrTiO3. S and C doping improved the photocatalytic activity of the doped SrTiO3 for oxidation of 2-propanol. Under a wide range of light irradiation at wavelengths longer than 350 nm, the photocatalytic activity levels of C, S cation-codoped SrTiO3 were about two times higher than those of pure SrTiO3. We found that a new absorption edge was formed in the visible light region due to doping of S and C atoms. The formation of this new absorption edge might be the reason for the high level of visible-light photocatalytic activity of this substance. (c) 2005 Elsevier B.V. All rights reserved.