Facile synthesis of hierarchical S-scheme In2S3/Bi2WO6 heterostructures with enhanced photocatalytic activity

Construction of heterojunction photocatalysts is a valid tactics to boost the photocatalytic property of catalyst. Herein, a novel S-scheme heterojunction of zero/three dimensional (0D/3D) In2S3/Bi2WO6 hybrid catalyst was obtained by assembling In2S3 nanoparticles on floriated shaped Bi2WO6 microsphere through a simple precipitation route for the first time. The morphology, structures, composition, chemical and optical properties of the resulting materials were carefully researched through various instruments. The degradation experiments revealed that In2S3/Bi2WO6 composites exhibited superior photocatalytic behavior for dyes decomposition. The optimized In2S3/Bi2WO6 composite showed remarkable photocatalytic decomposition Rhodamine B (RhB) and Methylene blue (MB), 16.0 (2.68)-fold and 70.3 (1.66)-fold larger than that of pristine Bi2WO6 (In2S3), and it also possessed good stability and reusability. The largely improved photoactivity may derive from the formed S-scheme heterojunction between Bi2WO6 and In2S3, which accelerated photocarriers disassociation and retained strong redox power. Liquid chromatography-mass spectrometry (LC-MS) was applied to reveal the RhB decomposition pathway. Besides, the S-scheme charge transfer mechanism was well elucidated based on in-situ X-ray photoelectron spectroscopy analysis, density functional theory calculation (DFT), and trapping experiment along with electron paramagnetic resonance (EPR) tests.