Modulating the large vacancy types of CuS ultrathin nanosheets via defect engineering to improve the photocatalytic antibacterial performance

Defect engineering is emerging as an important tool for tuning the photocatalytic antibacterial properties of nanomaterials. However, its development is constrained by the lack of exploration of defect engineering for large defect types. We designed CuS and CuS-200 ultrathin nanosheets with different large vacancy types VCuSSCuCu and VCuSSCuCuCu, respectively. The antibacterial test results demonstrated that CuS-200 ultrathin nanosheets exhibited stronger bactericidal effect on Escherichia coli (E. coli) than CuS under near-infrared (NIR) light. The high antibacterial efficiency was attributed to the improved energy band structure, which helped CuS-200 absorb light and improved photothermal conversion efficiency. In addition, the optimized electronic structure and the strong oxygen adsorption ability drove CuS-200 to produce a large amount of reactive oxygen species (ROS). This work provided new ideas for the preparation of efficient bactericides and new strategies for the design and preparation of catalysts with specific photocatalytic properties.