Optimized photocatalytic performance of ZnS-SnO2 heterostructures for visible light driven mineralization of Acid violet 7 dye and inactivation of bacteria

The present study aims to decipher the defect-induced photocatalytic activity of ZnS-SnO2 heterostructure for visible light-assisted oxidative mineralization of Acid Violet 7 dye (AV7) and Escherichia coli (E. coli) bacterial disinfection. The prepared ZnS-SnO2 (60ZS) heterostructure/nanocomposite catalysts show improved optical and visible light absorption properties. Photoluminescence findings reveal the existence of defect energy levels/surface states associated with 60ZS heterostructure catalysts. Photo/Electrochemical studies show improved photocurrent response, high capacitance, lower charge transfer resistance, and improved charge-discharge behaviour in 60ZS heterostructure catalysts compared to individual components. The improved photocatalytic performance of 60ZS heterostructure is ascribed to the interactive effect of a reduction in the band gap, improved surface area, and enhanced lifetime of photogenerated charge carriers. The major reactive species that cause the degradation reaction have been identified, and a plausible AV7 dye degradation pathway has been proposed. The 60ZS heterostructure catalyst exhibits good stability and a recycled nature.