Effects of 4d transition metals doping on the photocatalytic activities of anatase TiO2 (101) surface

Aiming at improving the visible‐light photocatalytic activities of TiO2(101) surface we make an in‐depth study on the TiO2(101) doped with 4d transition metal (TM) atoms. It is shown that the 4d TM dopings can not only produce new impurity energy bands in the band gap but also result in the semiconductor–metal phase transition. Consequently, the visible‐light absorption is strongly strengthened due to the dopings of Y, Zr, Nb, Mo, and Ag, while it is only weakly improved for Tc, Ru, Rh, Pd, and Cd dopings. The improvement in visible‐light absorption can be attributed to the intraband or interband transition of electrons. Moreover, the photocatalytic activities are explored, and we find Y and Ag dopings can effectively enhance the photocatalytic activity of TiO2(101) surface. Thus the mechanism of improving photocatalytic activity of TiO2(101) has been clearly addressed, which is beneficial to further experimental and theoretical researches on TiO2 photocatalysts. A comparative investigation on the photocatalytic activities of TiO2(101) doped by all 4d transition metals is carried out based on the density functional theory. The visible‐light absorption coefficient can be enhanced to different extent by doping 4d transition metals, which may be caused by the intraband or interband transition of electrons.