Fabrication of Z-scheme ZnIn2S4–CdS heterojunction photocatalyst in-situ grown on novel graphene-based substrate for the photocatalytic reduction of Cr(VI)

The synthesis of novel film-like photocatalysts is an effective strategy for reducing Cr(VI). Herein, a Z-scheme ZnIn 2 S 4 –CdS heterojunction photocatalyst was fabricated on a self-assembled graphene-based substrate via hydrothermal and solvothermal methods. By controlling the ethanol:water ratio during solvothermal synthesis, differently sized CdS nanoparticles were grown on the ZnIn 2 S 4 nanosheets surface for regulating the photocatalytic activity of ZnIn 2 S 4 –CdS heterojunction. The three-dimensional layered structure of the graphene film provided abundant active sites for material loading and its excellent conductivity rapidly transferred photogenerated electrons. Compared to the ZnIn 2 S 4 –CdS heterojunction samples with other controlled structure, graphene-based film-like photocatalyst bring advantage in enrich photocatalysts for bursting out better activity. Under visible light irradiation, the synthesized RZC-40 sample exhibited a photocatalytic efficiency of 91.02% in photoreducing 20 mg L −1 Cr(VI) within 50 min, highlighting the feasibility and promising practical application prospects of synergistic film-like photocatalysts and laying a theoretical foundation for the further development of photocatalysts with improved activity.