Visible-light-driven antibacterial photocatalyst based on Ag nanoparticle-decorated N-vacancy g-C ₃ N ₄ nanosheets

The rapid rise of antibiotic resistance threatens global health, highlighting the need for new antimicrobial strategies. Here, we investigated nitrogen vacancies and Ag nanoparticles decoration in carbon nitride (Ag-g-C₃N₄-V). Nitrogen vacancies optimized the electronic structure, boosting light absorption and charge separation. Ag nanoparticles induced a synergistic effect via localized surface plasmon resonance and the conjugated C₃N₄network, enhancing visible-light photocatalysis. The composite promoted hydrogen peroxide (H₂O₂) generation, a reactive oxygen species with antibacterial activity. The incorporation of Ag synergistically coupled H₂O₂generation with Ag⁺release, leading to enhanced bactericidal performance. Treatment with Ag-g-C₃N₄-V reduces the survival rates of<i>E. coli</i>and<i>S. aureus</i>by approximately 39% and 58% respectively compared to the control group; under light conditions, Ag-g-C₃N₄-V lowers the survival rates of<i>E. coli</i>and<i>S. aureus</i>to only 16% and 6%, showing a more remarkable bactericidal effect. This work offers a strategy for designing multifunctional photocatalysts against bacterial infections with potential biomedical applications.