Defect-Engineered Porous C3N4/CoFe-LDH Quantum Dot Heterostructures for Synergistic Photocatalytic-Nanozyme Antibacterial Therapy.

Bacterial infections and the spread of multidrug-resistant pathogens pose a growing threat to public health as conventional antibiotics lose efficacy, necessitating efficient non-antibiotic antibacterial strategies. Although ROS-based photocatalysis and nanozyme catalysis are promising, single-component systems are often limited by charge-carrier recombination, low ROS generation efficiency, and slow reaction kinetics. Herein, we report a porous C3N4@oxygen-vacancy-rich CoFe-LDH quantum-dot (p-CN@CF-O) composite heterostructure, in which ultrasmall CoFe-LDH quantum dots are uniformly anchored onto the surface of porous C3N4 (p-CN), forming robust and intimate heterointerfaces. The defect-rich p-CN framework facilitates charge transport and reactant adsorption, while oxygen vacancies in the CoFe-LDH quantum dots markedly enhance peroxidase-like activity and promote interfacial charge separation. The cooperative effect of multilevel defects significantly boosts ROS generation, enabling highly efficient antibacterial activity under mild conditions. Moreover, the composite serves as a micro-scaffold that supports epidermal cell proliferation and migration. In a skin infection model in vivo, this material effectively eradicates bacteria, suppresses biofilm formation, and accelerates wound healing, demonstrating outstanding potential for skin anti-infective therapy. This work not only establishes an efficient photocatalysis-nanozyme synergistic antibacterial strategy, but also provides valuable insights into the rational design and mechanistic understanding of heterostructured antibacterial materials.