Zn–N bonds boost interfacial charge transfer in ZnO/Nitrogen-Doped porous carbon Schottky heterojunction for enhanced photocatalytic sterilization

Abstract

Although heterogeneous photocatalytic sterilization can avoid secondary pollution and achieve broad spectrum antibacterial effects, its low disinfection efficiency seriously hinders its development. Exploring and achieving precise electron-transfer channels in the interface of heterogeneous systems are an effective method to enhance photocatalytic sterilization. Herein, we designed a chemical Zn–N bonded nitrogen-doped porous carbon-loaded zinc oxide (ZnO/NC) Schottky heterojunction photocatalyst through oxidizing and carbonizing ZIF-8 in-situ at suitable temperatures. The Zn–N accurately facilitated the photogenerated electrons transfer from the conduction band (CB) site of ZnO to the NC surface as active site. Furthermore, the NC as carrier enhanced the light-absorption capacity (746 nm) of Schottky heterojunction and functioned as active site to promote the generation of reactive oxygen species (ROS). In addition, the slow-release effect of zinc ions (Zn2+) from ZnO contributed to the accelerated death of bacteria. As a result, under simulated sunlight conditions, the ZnO/NC-400(1 h) Schottky heterojunction demonstrated an impressive antibacterial efficiency of 99.33 % against Escherichia coli, consistently exceeding 95 % in repeated experiments. This work presents a controllable and encouraging approach for constructing heterojunction with effective antibacterial properties.