Al, N Codoping and the Effect of O Vacancy in Photocatalyst SrTiO₃

Abstract

In light of the potential for enhancing SrTiO3 (STO)'s photocatalytic efficiency, particularly in the visible light region, a study is conducted on Al, N codoping in STO herein using first‐principles calculations. The effect of oxygen vacancy (VO) is also considered. It is found that AlSr, NO can significantly reduce the bandgap; however, their formation energies are rather high, and the defect levels they brought in may induce recombination centers. Under O‐deficient conditions, VO can facilitate Al, N doping in STO. When Al, N codope in STO, AlTi, NO, and VO would tend to combine, and formation of complex defect AlTi + NO + VO can further enhance N dopability in STO. Moreover, AlTi + NO + VO can simultaneously reduce the bandgap and eliminate the defect levels induced by NO. However, AlTi + NO + VO may not fully realize the potential for the photocatalytic activity due to the low optical absorption and unsuitable band alignment. The work provides a theoretical guidance for the photocatalytic performance of STO in the visible light region.