A First-Principles Study on Electronic Properties of Ce/N Codoped Anatase TiO2

Abstract

Density function theory is performed in order to investigate the effect of Ce/N co-doping on geometry structure, electronic and optical properties of anatase TiO2. Comparing the energy band and density of states of pure TiO2 and Ce/N doped anatase TiO2. We can conclude that, the valence band of pure TiO2 is main composed of O 2p states and the conduction is mainly composed of Ti 3d states. For N-doped TiO2, the topmost part of the valence band is mainly occupied by N 2p states which is higher than that of the O 2p states which can narrowed the band gap. Ce doping will introduce 4f states which is involved in the conduction band. These may lead the conduction band move down. As for Ce and N co-doped, the top of the valence band is mainly occupied by an admixture N 2p, O 2p and the bottom of the conduction band is predominantly occupied by an admixture of Ce 4f ,Ti 3d. The strong interaction between the dopants and the ions lead the band gap get narrower. We predict that Ce+N doping is one of the best choices for enhancing the photoelectrochemical activity of TiO2.