V2O5/ZnIn2S4 composite nanoflowers: a high-performance visible-light photocatalyst with S-scheme heterojunction

The utilization of visible light for photocatalytic degradation has always been a key objective in the field of photocatalysis. In this work, we designed and synthesized an efficient visible-light photocatalyst: V 2 O 5 /ZnIn 2 S 4 (VOZ) nanoflower composite structure. The flower-like ZnIn 2 S 4 , self-assembled from nanosheets, was prepared via a hydrothermal method, followed by the in-situ growth of V 2 O 5 nanoparticles on the nanosheets of ZnIn 2 S 4 through a chemical reaction approach. The results from XPS, PL, ESR and other characterization methods revealed that V 2 O 5 and ZnIn 2 S 4 formed an S-scheme heterojunction, enabling efficient carrier separation and migration while retaining the oxidation capability of V 2 O 5 and the reduction capability of ZnIn 2 S 4 . Under visible light irradiation for 80 min, the composite achieved a 97.4 % degradation for methylene blue (MB), outperforming pure V 2 O 5 and ZnIn 2 S 4 by factors of 1.53 and 1.92, respectively. Similarly, VOZ-20 achieved over 90 % degradation of both methyl orange (MO) and rhodamine B (RhB) within 80 min of visible-light irradiation. Additionally, ICP-OES analysis revealed that the solubility of V 2 O 5 in water was significantly reduced after forming a composite with ZnIn 2 S 4 , which helps prevent vanadium ion contamination in aqueous environments. This composite, with its strong redox activity and simple synthesis, is highly promising for visible-light photocatalytic applications.