Solvated Electron-Driven Stepwise ORR on Na-Metalated N-Rich Carbon Nitride for Efficient Photocatalytic H₂O₂...

Solvated electrons (SEs), known for their strong reductive capability, are widely utilized in diverse catalytic reactions. However, their application in photocatalytic oxygen reduction reactions (ORR) for hydrogen peroxide (H₂O₂) production remains largely unexplored. In this work, a Na-metalated, N-rich poly(heptazine imide)-type carbon nitride (PH-C₃N₅-Na), synthesized via a NaCl/LiCl molten salt-assisted method is reported, as a novel photocatalyst for in situ SE-driven H₂O₂ production. The N-rich units and Na into Polymetric carbon nitride (PCN) synergistically narrows the bandgap and facilitates rapid electron transfer, thereby enhancing visible-light absorption and promoting efficient charge separation. Notably, Na metalation enables the generation of solvated electrons under light irradiation, which mediates a stepwise 2e^- ORR pathway via superoxide radicals (•O₂ ^-), significantly boosting H₂O₂ production. As a result, PH-C₃N₅-Na delivers an impressive H₂O₂ production rate of 245.51 µmol·h^-1, 206 times higher than that of PM-C₃N₅-550, accompanied by an exceptional apparent quantum efficiency of 54.4% (AQE) at 420 nm. This study presents a new strategy for the rational design of high-performance photocatalysts and unveils the critical role of solvated electrons in enhancing photocatalytic ORR for sustainable H₂O₂ synthesis.