Enhanced visible-light photocatalytic activity of anatase TiO2 through N and S codoping

The density of states and optical properties of N, S, and (N, S)-doped anatase TiO2 are calculated based on the density functional theory. The results indicate that the doping S atoms occupy the Ti-atom sites in anatase TiO2 lattice. The mixing of O 2p, N 2p, S 3p, and Ti 3d states in the forbidden gap of (N, S)-codoped TiO2 can result in the higher visible-light photocatalytic activities than those monodoped TiO2. For comparison, (N, S)-codoped TiO2 was also synthesized by one-step hydrothermal method, and the optical absorption spectra obtained by experiments verified the reliability of our calculation. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3593147]