A 2D-2D heterojunction Bi2WO6/WS2-x as a broad-spectrum bactericide: Sulfur vacancies mediate the interface interactions between biology and nanomaterials.

We report a heterojunction Bi2WO6/WS2-x with sulfur vacancies as a broad-spectrum bactericide to efficiently kill Gram-positive and Gram-negative bacteria in vitro and in vivo under visible-light irradiation. Sulfur vacancies in single-layer WS2 make the surface electron-rich. Integration of Bi2WO6 with WS2 enhances the photoelectric activity under visible-light irradiation. Sulfur vacancies promote the generation of radicals and the extraction of membrane phospholipids from bacterial cells. Density functional theory verifies that S vacancies strengthen the interactions between the Bi2WO6/WS2-x surface and H2O, enhancing the generation of ·OH. Two-dimensional correlation spectroscopy analysis reveals that perturbation of β-sheet proteins and formation of outer-sphere surface complexes contribute to the high antibacterial capacity. Bi2WO6/WS2-x accelerates the re-epithelialization and healing of infected wounds in an animal model. Uncommonly, Bi2WO6/WS2-x does not exhibit drug resistance and is biocompatible with human cells. Our results indicate that vacancy-functionalized heterojunctions are potentially promising antibacterial agents by regulating the interface interaction between biology and nanomaterials.