Construction of Ag: ZnIn2S4/Bi2S3 Z-scheme heterojunctions for boosting interfacial charge separation and photocatalytic degradation of TC

The construction of Z-scheme heterostructures is one of the most effective strategies to improve photocatalytic efficiency. In this study, Ag+ doped ZnIn2S4/Bi2S3 composite nanosphere materials with different mass fractions of Bi2S3 were successfully synthesized by the solvothermal method. Systematic studies showed that the construction of heterogeneous structures and Ag+ doping could extend the optical absorption edge and provide more active sites. More importantly, it was shown by photoelectrochemical and PL spectroscopy tests that Ag: ZnIn2S4/Bi2S3 has strong visible light absorption and photocarrier transfer capability. In addition, the Z-scheme mechanism of Ag: ZnIn2S4/Bi2S3 was investigated by electron spin response (ESR) and active substance capture experiments, which confirmed that both superoxide radicals(O−2) and hydroxyl radicals(OH) were involved in the photocatalytic reaction. The results showed that the optimized Ag: ZnIn2S4/2.5%Bi2S3 degraded TC by 89.7%, 1.87 times higher than the original ZnIn2S4. This work provides a promising method for the construction of Z-scheme heterojunctions based on ZnIn2S4.