Antibacterial Properties and Application of Bi₂Sn₂O₇/ZnO Composite Photocatalytic Materials

In this experiment, Bi₂Sn₂O₇/ZnO composite photocatalytic materials were synthesized by a hydrothermal method and characterized by XRD, SEM, and EDS, etc. The prepared Bi₂Sn₂O₇/ZnO has a nanorod structure and high phase purity. The photocatalytic antimicrobial performance of Bi₂Sn₂O₇/ZnO against bacteria and fungi under visible light was significantly better than that of single Bi₂Sn₂O₇ and ZnO. In particular, 1000 mg/L 1 : 3 Bi₂Sn₂O₇/ZnO showed an antimicrobial rate of more than 97 % against Escherichia coli, Staphylococcus aureus, and Candida albicans, which are widely present in the nature. The free radical trapping experiments were selected and the antimicrobial mechanism was investigated, and the results showed that the antimicrobial process of the Bi₂Sn₂O₇/ZnO system was regulated by the free radicals such as ⋅OH, h⁺, and e^-, which were generated by its unique photocatalytic activity. Finally, MTT cytotoxicity experiments demonstrated that the Bi₂Sn₂O₇/ZnO composite was not toxic to cells. In addition, the antimicrobial performance of Bi₂Sn₂O₇/ZnO on real livestock wastewater and the real-life application of the prepared Bi₂Sn₂O₇/ZnO PCL composite antibiotic film for antimicrobial treatment of freshly cut fruits' surfaces under visible light were experimentally investigated. This study provides a new idea for Bi₂Sn₂O₇/ZnO as a photocatalytic antimicrobial agent.