Establishing rapid charge channel via synergism of oxygen vacancy and interfacial effect to promote stable photocatalytic NO purification

Abstract

Developing efficient and economical photocatalysts is critical to the practical application of nitrogen oxide (NOx) photocatalytic purification technology. At the same time, the spatial separation and migration of charges were extremely limited by the energy band mismatch and limited adaptability of the heterojunction. Herein, the interfacial effect of AgBr/Bi4O5Br2 heterojunctions with oxygen vacancies (OVs) was established to modify the interface and surface properties for enhance the photocatalytic performance. As a result, the optimal OVs-Bi4O5Br2/AgBr composite exhibited a maximum NO removal rate of 66.4 % (728 ppb → 245 ppb) and high stability for 600 min under visible light. The results show that an internal electric field could be formed by the synergism of the oxygen vacancy and interfacial effect to provide a rapid charge transport channel, which improved the separation efficiency of photo-generated carriers. It also generated abundant reactive oxygen species (ROS), which enhanced the photocatalytic NO purification performance. The present work provided a valuable design strategy for rapid charge transfer-based photocatalysts for pollutant treatment.