Controlling the Electronic Structures of Perovskite Oxynitrides and their Solid Solutions for Photocatalysis

Abstract Band‐gap engineering of oxide materials is of great interest for optoelectronics, photovoltaics, and photocatalysis applications. In this study, electronic structures of perovskite oxynitrides, LaTiO 2 N and SrNbO 2 N, and solid solutions, (SrTiO 3 ) 1− x (LaTiO 2 N) x and (SrTiO 3 ) 1− x (SrNbO 2 N) x , are investigated using hybrid density functional calculations. Band gaps of LaTiO 2 N and SrNbO 2 N are much smaller than that of SrTiO 3 owing to the formation of a N 2p band, which is higher in energy than the O 2p band. The valence‐ and conduction‐band offsets of SrTiO 3 /LaTiO 2 N and SrTiO 3 /SrNbO 2 N are computed, and the adequacy for H 2 evolution is analyzed by comparing the positions of the band edges with respect to the standard hydrogen electrode (SHE). The band gap of (SrTiO 3 ) 1− x (LaTiO 2 N) x and (SrTiO 3 ) 1− x (SrNbO 2 N) x solid solutions are also discussed.