A first-principles study of the effect of oxygen vacancy on rutile Ti1−xCdxO2

A first-principles study has been performed to understand the effect of oxygen vacancy on the electronic properties of cadmium doped rutile TiO2. We observe that Cd incorporation on rutile TiO2 induces Cd p-states on the top of the valence band which is consistent with an earlier result of Zhang et al. (2008) [5]. Furthermore, by creating an oxygen vacancy, some new states are induced, which originate from the Ti 3d electrons at the middle of the band gap and spread up to the conduction band. Therefore, the band gap of the material reduces significantly, making it suitable to act as a better photocatalyst.

► Influence of oxygen vacancy on the electronic properties of Cd doped TiO2.
► Cd doping on rutile TiO2 induces some states close to the top of valence band.
► Oxygen vacancy induces some new states almost at the middle of the band gap.
► Combined effects can lead to a better photocatalyst in the visible energy range.
► Oxygen vacancy closest to Cd atom shows more favorable and desirable effects.