Effects of Ba–O codoping on the photocatalytic activities of Ta3N5 photocatalyst: a DFT study

Abstract

The Ta₃N₅ semiconductor is a promising photocatalyst but its practical solar-to-hydrogen efficiency is low and the stoichiometric H₂ and O₂ evolution of Ta₃N₅ is still difficult. Recent experiments reveal that Ba-doped Ta₃N₅ presents excellent photocatalytic performance. In this study, density functional theory calculations are performed to unravel the effects of Ba–O codoping on the photocatalytic abilities of Ta₃N₅. The results reveal that the enhanced photocatalytic activities of the Ba–O codoped Ta₃N₅ is ascribed to the charge compensation between Ba and O, because the charge compensation induces the cathodic shift of the conduction band minimum of Ta₃N₅, thus improving the water reduction ability of Ta₃N₅.