Atomic Zn–N<sub>4</sub> Site-Regulated Donor–Acceptor\nCatalyst for Boosting Photocatalytic Bactericidal Activity

Reactive\noxygen species (ROS)-mediated photocatalytic antibacterial\nmaterials are emerging as promising alternatives for the antibiotic-free\ntherapy of drug-resistant bacterial infections. However, the overall\nefficiency of photocatalytic sterilization is restricted by the rapid\nrecombination of the charge carriers. Herein, we design an in-plane\nπ-conjugated donor–acceptor (D–A) system (g-C<sub>3</sub>N<sub>4</sub>–Zn-NC), comprising graphitic carbon nitride\n(g-C<sub>3</sub>N<sub>4</sub>) as the donor and Zn single-atom anchored\nnitrogen-doped carbon (Zn-NC) as the acceptor. Experimental and theoretical\nresults reveal that the introduction of Zn-NC induces the formation\nof an intermediate band in g-C<sub>3</sub>N<sub>4</sub>–Zn-NC,\nextending the spectral absorption range and facilitating charge carrier\ntransfer and separation. Additionally, the synergistic effects of\nthe dual sites, the NC–N sites of the g-C<sub>3</sub>N<sub>4</sub> “donor” and the atomic Zn–N<sub>4</sub> sites of the Zn-NC “acceptor”, boost ROS production.\nConsequently, the biocompatible g-C<sub>3</sub>N<sub>4</sub>–Zn-NC\neffectively kills methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) under visible-light irradiation and promotes the healing\nof MRSA-infected wounds on mouse skin.