Nanocavity Confining Platinum Nanoclusters Enhances Photocatalytic Two‐Electron Oxygen Reduction for Wound Healing

ABSTRACT Photocatalytic two‐electron oxygen reduction reaction (ORR) toward H 2 O 2 synthesis is a compelling approach for clinical antibacterial applications. Yet its selectivity is hampered by the competing four‐electron ORR, which compromises both H 2 O 2 generation kinetics and antibacterial efficiency. Herein, we report a new nanoscale confinement strategy for the controllable synthesis of covalent organic frameworks (COFs) confining isolated platinum nanoclusters (NCs) to enhance Pauling‐type of O 2 adsorption to achieve two‐electron oxygen reduction for efficient antibacterial therapy. The resulting Tfp‐Db COFs@Pt NCs exhibits a significantly higher H 2 O 2 formation kinetics (3.12 × 10− 3 mol L −1 h −1 ) than Tfp‐Db COFs@Pt nanoparticles (1.55 × 10 −3 mol L −1 h −1 ), with 2e − ORR selectivity increased from 45.0% to 86.0%. Experimental and theoretical results reveal a two‐step single electron oxygen reduction pathway for H 2 O 2 photosynthesis over Tfp‐Db COFs@Pt NCs. The Tfp‐Db COFs@Pt NCs exhibits excellent sterilization efficiencies of 5.0 log 10 CFU mL −1 and 5.2 log 10 CFU mL −1 against S. aureus and E. coli , respectively, exceeding most reported materials. Furthermore, Tfp‐Db COFs@Pt NCs facilitate the regeneration of infectious wounds, with the efficiency of nearly 100% on day 10, outperforming previously reported bionanomaterials. Collectively, this work presents a new strategy for regulating the Pauling‐type of O 2 adsorption to enhance the photocatalytic H 2 O 2 formation for wound healing application.