The enhanced photocatalytic properties of MnO₂/g-C₃N₄ heterostructure for rapid sterilization under visible light

Herein, a heterostructure based on MnO₂ and g-C₃N₄ was constructed on the surface of metallic Ti implants, in which MnO₂ favored the transfer and separation of free charges to enhance the photoconversion efficiency of g-C₃N₄ by 21.11%. Consequently, the yield of ROS was promoted significantly, which denatured protein and damaged DNA to kill bacteria efficiently. In addition, glutathione (GSH, l-γ-glutamyl-l-cysteinyl-glycine) defending oxidative stress in bacteria, was oxidized by MnO₂ in the hybrid coating once the bacterial membrane was disrupted by ROS. Hence, after visible light irradiation for 20 min, MnO₂/g-C₃N₄ coating exhibited superior disinfection efficacy of 99.96% and 99.26% against S. aureus and E. coli severally. This work provided a practical sterilization strategy about MnO₂/g-C₃N₄ systems through the synergistic effects of enhanced photodynamic antibacterial therapy and oxidization effect of MnO₂ with great biosafety, in which MnO₂ enhanced the photocatalyst property of g-C₃N₄ to generate more ROS and deplete GSH to improve antibacterial efficiency. It will bring more insight into rapid and highly effective disinfection and antibacterial strategy without using traditional high-temperature, ultraviolet ray and antibiotics that cause side-effects.