H‐Bonds in Carbon Quantum Dot‐anchored C 3 N 5 to Boost Proton‐Coupled Electron Transfer for Piezoelectric‐Driven Hydrogen Peroxide Synthesis under Ambient Conditions

Abstract Tuning proton‐coupled electron transfer (PCET) is a promising strategy to boost the oxygen reduction reaction (ORR) for hydrogen peroxide (H 2 O 2 ) synthesis, but the slow transmission rate of protons and electrons to active sites remains a significant bottleneck. To address this, we developed an H‐bond‐driven PCET process based on carbon quantum dot‐anchored C 3 N 5 (CQDs‐C 3 N 5 ) for piezo‐catalytic H 2 O 2 synthesis. CQDs‐C 3 N 5 exhibited a remarkable piezo‐catalytic synthesis rate of 5025 μmol g −1 h −1 under ambient conditions, surpassing that of most reported piezoelectric materials. This efficiency is attributed to the intermolecular H‐bonds between CQDs and C 3 N 5 , which significantly accelerate PCET in the ORR. The piezoelectric‐generated charges, from the dipole field of the C 3 N 5 plane, and protons in water, were rapidly transferred to the C rings of CQDs via H‐bond networks. This process facilitated the adsorption of oxygen onto the C2 sites adjacent to the carboxyl groups of CQDs, which in turn led to the formation of H 2 O 2 through a rapidly protonated, indirect 2e − pathway. Additionally, a piezo‐self‐Fenton reaction system was constructed for oxytetracycline‐rich wastewater purification, with effectively effects on chemical oxygen demand, antibiotic‐resistant bacteria and antibiotic‐resistant genes degradation, etc . This study highlights the critical role of H‐bond networks for tuning PCET in the ORR and provides a comprehensive understanding for the precise control of catalytic reaction kinetics through molecular structural engineering.