Interfacial charge transfer and enhanced photocatalytic performance for the heterojunction WO3/BiOCl: first-principles study

Abstract

First-principles calculations based on density functional theory were carried out to explore the interfacial properties of the WO₃/BiOCl heterojunction aiming at gaining insights into the roles the interface played in the overall photocatalytic performance. The interfacial effects of the WO₃ combination with BiOCl on electronic properties, charge transfer and visible-light response were investigated in detail. The density of states analysis showed that the interfacial structures resulted in a suitable band alignment to separate the excited carriers into two sides of the interface and thus, the electrons–holes recombination could be effectively suppressed. Moreover, excited holes could be readily transferred across the interface from the valence band maximum (VBM) of BiOCl to the VBM of WO₃ under visible-light irradiation without being trapped in interfacial mid-gap states.