Construction of a direct Z-scheme Sn3O4/In2O3 heterostructure: Boosting photocatalytic degradation of contaminants

Constructing a heterostructure is regarded as one of the most promising strategies for boosting light absorption and promoting the separation of photoinduced charge carriers in the field of photocatalysis. In this study, a Z-scheme Sn₃O₄/In₂O₃ heterostructure was constructed by in-situ growth of Sn₃O₄ nanosheets directly on In₂O₃ microtubes. The optimized SI-0.1 heterostructure demonstrated superior photocatalytic activity, with degradation efficiencies of 90.6 % for methyl orange (MO) and 99.0 % for Cr(VI), respectively. Notably, the rate constants for MO photodegradation and Cr(Ⅵ) photoreduction over SI-0.1 were 2.5 and 3.5 times higher than those of pristine Sn₃O₄ nanosheets, and 29 and 6.3 times greater than those of In₂O₃ microtubes. The exceptional photocatalytic efficiency is primarily attributed to boosted visible-light absorption, elevated reactive sites, and the close contact at the dual-shell interface, which promote effective charges separation and migration. The typical Z-scheme heterojunction between Sn₃O₄ and In₂O₃ was thoroughly discussed to elucidate its photocatalytic mechanism. This work offers significant insights for designing efficient photocatalytic heterostructures for wastewater treatment applications.