Z-scheme AgVO₃/ZnIn₂S₄ photocatalysts: “One Stone and Two Birds” strategy to solve photocorrosion and improve the photocatalytic activity and stability

At present, photocorrosion is one of the factors that seriously restrict the improvement of photocatalytic performance. Herein, we successfully constructed AgVO₃/ZnIn₂S₄ composite photocatalysts with the property of “One Stone and Two Birds”, which solved two urgent problems simultaneously, the S-metal bonds of sulfide are easily oxidized by photogenerated holes and the Ag⁺ of Ag-based photocatalysts are easily reduced by photogenerated electrons. Additionally, the Ag NPs were precipitated automatically during the synthesis of AgVO₃/ZnIn₂S₄, which favor to enhance the transfer rate of the photogenerated carriers and remain strong redox ability of the AgVO₃/ZnIn₂S₄ photocatalysts. The as-prepared 20% AgVO₃/ZnIn₂S₄ exhibited the top-flight photocatalytic reduction of Cr (VI) activity. In addition, the effects of pH value and temperature on the photocatalytic reduction of Cr (VI) were investigated in depth. Simultaneously, the photocatalytic reduction activity was further verified based on biotoxicity assessments and toxicity predictions of the products. At the same time, the photocatalyst showed good photocatalytic degradation activity to 2-mercaptobenzothiazole (MBT) and ciprofloxacin (CIP). In addition, the AgVO₃/ZnIn₂S₄ photocatalysts possessed superior cycle performance and structural stability. The enhanced activity and stability were ascribed to the successfully suppressed the photocorrosion of both AgVO₃ and ZnIn₂S₄ by transferring the photogenerated electrons and holes to Ag NPs.