One-pot synthesis of Bi₂S₃/Bi₄O₅Br₂ S-scheme heterojunction hierarchical microbelts with enhanced photocatalytic activity in contaminant degradation

Constructing heterojunctions is an effective way to enhance photocatalytic activity of semiconductors and enlarging heterojunction interface area is a key point. Herein, one-dimensional Bi2S3/Bi4O5Br2 S-scheme heterojunction hierarchical microbelts were synthesized through a facile one-pot solvothermal method, using bismuth subsalicylate as the hard template. In the heterojunction microbelts, Bi2S3 nanoparticles are homogeneously dispersed in the Bi4O5Br2 matrix, which considerably enlarges the S-scheme heterojunction interface. These heterojunction hierarchical architectures can remarkably enhance photogenerated charge separation and thus photocatalytic activity of the Bi2S3/Bi4O5Br2 microbelts which, for example, exhibit a similar to 2.6, 113, and 2.0 times higher photodegradation efficiency toward salicylic acid than Bi4O5Br2, Bi2S3, and Bi4O5Br2 loaded superficially with Bi2S3, respectively. Especially, the Bi2S3/Bi4O5Br2 heterojunction microbelts also exhibits high photoactivity in tap water, river water, and lake water under natural solar irradiation. This work provides a simple way to construct Bi-based heterojunction hierarchical architectures with large heterojunction interface area.