Boosted charge transfer in dual Z-scheme BiVO4@ZnIn2S4/Bi2Sn2O7 heterojunctions: towards superior photocatalytic properties for organic pollutant degradation

Abstract A core-shell structured dual Z-scheme ternary photocatalyst BiVO4@ZnIn2S4/Bi2Sn2O7 was fabricated via hydrothermal and heat-circumfluence strategy. With ZnIn2S4 serving as a bridge to connect BiVO4 and Bi2Sn2O7, the developed ternary catalyst displayed boosted charge transfer and spatial separation capabilities. The effect of mass ratios of BiVO4@ZnIn2S4 and Bi2Sn2O7 on photodegradation efficiency under visible light irradiation was explored. The optimal ternary heterojunction photocatalyst possessed remarkable photocatalytic rate constant for Rhodamine B (RhB) degradation, which was 63 and 12 times higher than that of BiVO4 and Bi2Sn2O7, respectively. In addition, the as-prepared ternary photocatalyst had good universality. Notably, the novel dual Z-scheme photocatalysts could improve the separating/transferring efficiency and reduction/oxidation ability of charge carriers. Meanwhile, the hierarchical structure offered sufficient reaction sites for photodegradation. This work provides a new insight into the rational design of ternary dual Z-scheme photocatalysts.