One-pot construction of robust BiOCl/ZnO p–n heterojunctions with semi-coherent interfaces toward improving charge separation for photodegradation enhancement

Abstract

Heterojunction engineering is an effective strategy to enhance photodegradation activity via improving the spatial charge separation. However, the poor interface interaction and stability limit the photocatalytic activity of traditional heterojunction. Herein, robust BiOCl/ZnO p-n heterojunctions with semi-coherent interfaces were prepared by a one-pot hydrothermal method to improve the activity and stability toward photocatalytic degradation than that of the counterpart, which was attributed to the formation of built-in electric field in this robust p-n heterojunction for enhanced charge separation. Optical and electrical properties revealed that the BiOCl/ZnO heterojunctions possessed the highest electron migration and charge separation efficiency. Density functional theory (DFT) calculations and electron spin-resonance (ESR) results verified that the enhanced photocatalytic performance was assigned to the type-II photocatalytic mechanism through the •OH and •O2− reactive oxygen species. This work would provoke the development of one-step constructing new high-active BiOX (X= Cl, Br and I)-based heterogeneous photocatalysts.