New insight into effects of 4d transition metals doping on the
photocatalytic activities of anatase TiO2(101) surface
Abstract
Aiming at improving the visible-light photocatalytic activities of
TiO2(101) surface (TiOS) we make an in-dept study on the TiOS 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 bandgap 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 TiOS.
Thus the mechanism of improving photocatalytic activity of TiOS has been
clearly addressed, which is beneficial to further experimental and
theoretical researches on TiO2 photocatalysts.