A hybrid density functional theory study of the anion distribution and applied electronic properties of the LaTiO2N semiconductor photocatalyst

Abstract

Although the crystallographic space group has been determined, detailed first principles calculations of the LaTiO₂N semiconductor photocatalyst crystal have not been performed because of the nitrogen/oxygen sosoloid-like anion distribution. In this study, based on the Heyd–Scuseria–Ernzerhof method and experimental anion content, we present the possibility of determining detailed information about the LaTiO₂N sosoloid-like anion distribution by dividing the anions into possible primitive cells. The detailed information about the anion distribution based on the characteristics of the energetically acceptable primitive cell structures suggests that the LaTiO₂N structure is composed of aperiodic stacks of six building-block primitive cells, the non-vacancy primitive cells are located at the surface as effective photoreaction sites, and vacancy structures are located in the bulk. The surface oxide-rich structures increase the near-surface conduction band minimum rise and strengthen photoelectron transport to the bulk, while the content of the bulk vacancy structures should be balanced because of being out of photoreactions. This study is expected to provide a different perspective to understanding the LaTiO₂N sosoloid-like anion distribution.