Insight into the enhanced photocatalytic activity of Mo and P codoped SrTiO(3) from first-principles prediction

In this study, the synergistic effect of cation codoping (Mo and the cation P) on the band structure of SrTiO(3) is demonstrated to enhance its photocatalytic activity. The electronic structure and optical properties of (Mo + P) codoped SrTiO(3) are examined by performing GGA + U calculations. The results show that the strong hybridization between the Mo 4d states and the O 2p states assisted by the non-metal P leads to the formation of fully occupied and delocalized intermediate states (IBs) near the valence band of SrTiO(3). The proximity of IBs to the valence band resulted in the ability to separate photo-excited electrons from reaction holes, which helps to ensure efficient electron replenishment reducing the probability of trapping electrons from the CB. This kind of metal Mo and non-metal P-compensated codoping can efficiently narrow the band gap and enhance the visible-light absorption. Moreover, the positions of the band edges after codoping (Mo + P) are found to be thermodynamically favorable for water splitting.