Ultrafine-Mn-Loaded N,O-Doped Nanocarbon via Mott‒Schottky Effect for Photo-Enhanced Antibacterial Therapy and Wound Healing

Bacterial infections are one of the greatest threats to wound healing, and microbial resistance has increased the demand for new antimicrobial dressings. Artificial nanozymes possess myriad considerable advantages, including low cost and high activity, for targeted biological treatments. Despite significant efforts made in nanozyme engineering, significant challenge remains that their catalytic performance is far from satisfactory in wound treatment. Herein, based on biowaste valorisation, we propose a sustainable and efficient strategy to synthesize an ultrafine-Mn-loaded (3.0 ± 1 nm) N,O-doped porous nanocarbons (Mn-PNCs) nanozyme via the Mott−Schottky effect. The nanozyme achieves mid-temperature (45.8°C) and superior photothermal conversion efficiency (77.62%), photothermally enhanced peroxidase-like activity that contributes to the effective treatment of methicillin-resistant Staphylococcus aureus-infected wounds. The photo-enzyme platform further reduced the inflammatory response, normalized epidermal tissue regeneration, and accelerated wound healing. Notably, the mechanism demonstrated that this Mott−Schottky catalyst can trigger the rapid transfer of electrons to release reactive oxygen species (ROS) species, as a heterojunction system is strongly capable of changing the electron density within the metal. Under photothermal induction, the Mott–Schottky contact can be used to fabricate other polysaccharide-derived nanozymes in tissue engineering, or on the high-value application of biomass resources.