Architecting in-plane bicrystals in BiOCl nanosheets for enhanced photocatalytic performance

Interface engineering has emerged as an effective strategy for addressing challenges related to insufficient solar light harvesting and poor photocharge separation in photocatalysis. The distinctive in-plane homogeneous architecture offers the potential for significant enhancements in both photocharge separation and solar light absorption. Herein, a simple one-pot hydrothermal method was developed to construct in-plane homogeneous BiOCl bicrystals within BiOCl nanosheets (BOC-B). During this process, thiourea plays a pivotal role in introducing dislocations to form bicrystal structure. As expected, the synthesized BOC-B samples exhibited substantially higher photocatalytic degradation activity for TC and RhB compared to BOC. Notably, the mechanism underlying effective solar light absorption and charge carrier separation, driven by the homogeneous bicrystal structure, was elucidated through a series of experimental evidences. This work introduces a novel homogeneous bicrystal structure in BiOCl photocatalysts to optimize catalytic activity, providing a framework for developing new BiOCl-based photocatalysts. • In-plane BiOCl bicrystals were synthesized by a facile one-pot hydrothermal synthesis. • Defect engineering induced interfacial dislocations to form bicrystalline structures. • Dislocation-induced mid-gap states in BiOCl bicrystals can broaden visible light absorption. • In-plane bicrystalline architectures can enhance the electron mobility and charge separation. • The improved photocatalytic removal of TC and RhB was achieved.