Solar‐driven seawater production H2O2 catalyzed by hydroxyl functionalized crystalline K‐doped g‐C3N4 under ambient conditions.

Three hydroxyl functionalized crystalline K‐doped g‐C3N4 were synthesized from dicyandiamide, melamine, ammonium chloride, ammonium oxalate, and ammonium citrate via ionothermal polycondensation using KCl as molten salt under N2 atmosphere, which served as efficient recyclable photocatalysis realized that generating H2O2 directly from seawater with air by 2e− ORR pathway under stimulated solar irradiation in ambient conditions. Under optimized conditions, the highest H2O2 production rate of 1622 μmol g−1 h−1 for duration of 10 h was obtained. The cycling performances of HPCN‐2 displayed reusable for five times without noticeably loss of its catalytic activity. This work presents a real safer, sustainable, and economical approach for production of H2O2 directly from abundant natural seawater. [ABSTRACT FROM AUTHOR]