Defect engineering of ultrathin 2D nanosheet BiOI/Bi for enhanced photothermal-catalytic synergistic bacteria-killing

Optical antibacterial agents present great potential in eliminating infectious pathogens. It is of great significance to construct effective photonic antibacterial agents with outstanding light absorption properties. Herein, 2D engineering defect nanosheets BiOI/Bi with Bi decoration and defect engineering (BiOI-DE) are constructed to perform photonic sterilization. On the one hand, the rational designed BiOI-DE can effectively promote the broad-spectrum light absorption ability to enhance the light utilization rate. On the other hand, the substantive structure can simultaneously harvest the enhanced photonic carriers and thermal effect when irradiated with high penetration ability NIR, further exhibiting higher activity in killing Escherichia coli (E. coli) than that of single BiOI with poor light absorption. The sterilization efficiency is over 99%. Moreover, the causes of the photothermal effect are discussed, indicating that the change of BiOI bandgap and surface bismuth decoration displays a critical role in enhancing light absorption and creating heat energy. In the meantime, the structural advancement of BiOI-DE effectively improves the photocatalytic activity, the synergistic photothermal-catalytic process establishes a favorable condition for improving antibacterial performance. This system provides rational design and potential inspiration for high efficient antibacterial strategy by employing defect engineering approaches.