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

In light of the potential for enhancing SrTiO 3 (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 (V O ) is also considered. It is found that Al Sr , N O 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, V O can facilitate Al, N doping in STO. When Al, N codope in STO, Al Ti , N O , and V O would tend to combine, and formation of complex defect Al Ti + N O + V O can further enhance N dopability in STO. Moreover, Al Ti + N O + V O can simultaneously reduce the bandgap and eliminate the defect levels induced by N O . However, Al Ti + N O + V O 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.