Optimizing the electronic structure of BiOBr via constructing oxygen-rich vacancies for highly efficient NIR light-driven antibacterial activity

Two-dimensional (2D) layered nanomaterials showed great promise in the photocatalysis due to their unique physical properties. Defect engineering enables significant optimization of the electronic structure of 2D nano -materials to further enhance their photocatalytic activity. Herein, we designed two oxygen-rich vacancies BiOBr (BBR) and oxygen-poor vacancies BiOBr (BBP) to investigate their photocatalytic activities. The results demonstrated that BBR exhibited much higher activity than BBP in killing Gram-negative (Escherichia coli, E. coli) and Gram-positive bacteria (Bacillus subtilis, B. subtilis) under 808 nm laser irradiation. The enhanced antibac-terial activity can be attributed to optimized electronic structure of BBR, which leads to more intimate in-teractions with bacteria, stronger absorption capacity to near-infrared (NIR) light, and longer photocarriers lifetime. Moreover, density functional theory (DFT) calculations demonstrated that BBR has a better adsorption of O2, which facilitates the generation of more reactive oxygen species (ROS) for superior activity. This work not only provides a facile approach for constructing oxygen-rich vacancies in BiOBr, but also but also offers new insights to the potential of 2D materials optimized by defect engineering for efficient NIR light-driven anti-bacterial activity.