Metal-free frustrated Lewis pairs on boron-doped nitrogen-deficient carbon nitride boosting photocatalytic hydrogen...

Developing efficient metal-free catalysts for the selective two-electron photoreduction of O₂ to H₂O₂ remains a formidable challenge in photocatalysis. Herein, we report a strategy to address this by engineering atomically dispersed frustrated Lewis pairs (FLPs) into boron-doped nitrogen-deficient carbon nitride (BNDCN). Structural analyses unambiguously identify electron-deficient boron and adjacent cyano-group nitrogen as complementary Lewis acid and base sites, forming well-defined FLP configurations. The optimized BNDCN catalyst achieves a remarkable H₂O₂ production rate of 11.3 mmol g^-1 h^-1 with an apparent quantum efficiency of 13.1% at 420 nm, ranking it among the best-performing metal-free photocatalysts. Moreover, the photocatalytic reaction solution exhibits significant antibacterial activity, underscoring its potential for practical applications. Combined mechanistic studies reveal that the tailored FLPs generate a strongly polarized local field that promotes exciton dissociation, reduces the exciton binding energy, and significantly enhances charge separation and transfer. The induced "push-pull" electronic effect simultaneously facilitates O₂ adsorption, stabilizes critical *OOH intermediates, and suppresses the OO bond cleavage, thereby exclusively steering the reaction along the two-electron reduction pathway. This work pioneers a design paradigm for constructing metal-free FLP photocatalysts, elucidates the pivotal role of local polarization in molecular activation, and offers fundamental insights for solar-driven chemical conversion.