Asymmetric Zn─N ₃ O ₁ Single‐Atom Sites Promote Hydroxyl Radical Generation for Natural‐Light‐Driven Inactivation of Drug‐Resistant Bacteria

Abstract

ABSTRACT Waterborne drug‐resistant bacteria pose a serious global health threat, underscoring the urgent need for highly efficient disinfection strategies. The photocatalytic generation of hydroxyl radicals (•OH) represents a green and powerful route for bacterial inactivation, yet its efficiency is often limited by the sluggish kinetics of the stepwise single‐electron oxygen reduction pathway. Herein, we report an atomic‐level design strategy by anchoring asymmetric Zn─N 3 O 1 sites onto ultrathin graphitic carbon nitride nanosheets (Zn 1 /OCN) to accelerate •OH production. The introduced Zn─N 3 O 1 sites create localized intermediate states that enable rapid trapping of photogenerated electrons at Zn single‐atom sites and prolong their lifetime, thereby driving a stepwise single‐electron oxygen reduction reaction (ORR) for efficient •OH generation. Simultaneously, adjacent C═O moieties act as hole‐trapping centers to drive water oxidation reaction (WOR), establishing a local reservoir of H 2 O 2 and protons that couples with the ORR process, thus forming a cooperative redox pathway for enhanced •OH production. Additionally, these asymmetric sites effectively lower the formation energies of *OOH and *OH intermediates, thereby accelerating both ORR and WOR processes and facilitating •OH generation. Consequently, Zn 1 /OCN achieves outstanding bactericidal performance, inactivating 99.9% of drug‐resistant bacteria, within 30 min under natural light, markedly outperforming representative photocatalytic antibacterial materials reported to date.