Novel S-scheme 2D/2D BiOBr/g-C3N4 heterojunctions with enhanced photocatalytic activity

The design and construction of heterojunction photocatalysts, which possess a staggered energy band structure and appropriate interfacial contact, is an effective way to achieve outstanding photocatalytic performance. In this study, 2D/2D BiOBr/g-C3N4 heterojunctions were successfully obtained by a convenient in situ self-assembly route. Under simulated sunlight irradiation, 99% of RhB (10 mg.L-1, 100 mL) was efficiently degraded by 1.5-BiOBr/g-C3N4 within 30 min, which is better than the performance of both BiOBr and g-C3N4, and it has superior stability. In addition, the composite also exhibits enhanced photocatalytic activity for H-2 production. The enhanced activity can be attributed to the intimate interface contact, the larger surface area, and the highly efficient separation of photoinduced electron-hole pairs. Based on the experimental results, a novel S-scheme model was proposed to illuminate the transfer process of charge carriers. This study presents a simple way to develop novel step-scheme photocatalysts for environmental and related applications. (C) 2021, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.