Modulating Local Proton Coverage and *OOH Generation via Coupled Multiple Sites for Enhanced Photocatalytic H₂O₂ Production

Rationally modulating the adsorption of reaction intermediates on the surface sites of carbon nitride-based catalysts could facilitate the photocatalytic reduction of O₂ to H₂O₂. Herein, theoretical calculations reveal that multiple sites of heteroatoms and defects can synergistically increase local proton coverage and lower the kinetic barrier for O₂ protonation, thereby promoting the production of *OOH and the subsequent generation of H₂O₂. As a proof of concept, carbon nitride (BPMC-Vs) with multiheteroatoms (B and P) and multidefects (N defects, ─C≡N) was successfully synthesized, achieving optimized solar-to-chemical conversion efficiency and selectivity of 0.33% and 95.2%, respectively. In situ spectroscopic characterization combined with theoretical calculations confirms that P atoms and ─C≡N groups increase proton coverage, while B atoms and N defects effectively promote the protonation of O₂ to *OOH, thereby significantly enhancing the generation of H₂O₂. This work provides insightful guidance for carbon nitride catalysis at the atomic scale for boosting photocatalytic H₂O₂ production.