Modulating the precursors of carbon nitride to boost local electron delocalization for H2O2 photosynthesis to remove oxytetracycline and its antibiotic resistant genes

Abstract

Artificial H2O2 photosynthesis, one of the brightest strategies toward H2O2 production, is always restricted by the intrinsically charge migration behaviors and redox kinetics of photocatalysts. Herein, different precursors of carbon nitride (C3N4) with urea and melamine (Mel) are synthesized, where C3N4-Urea has more delocalized electrons due to its smaller size and thickness, compared with C3N4-Mel. Under simulated sunlight irradiation, these abundant delocalized electrons rapid reduce oxygen into H2O2, with the rate of 4.9 mmol g−1 h−1 and 2e- transfer selectivity of 98%. In addition, a self-photo-Fenton reaction system is constructed to remove oxytetracycline (OTC) pollutants and its antibiotic resistant genes (ARG) in water, with the degradation rate of 3.75 min−1 for OTC and 0.08 min−1 for tetC ARG. The current approach by modulating the precursors of C3N4 to boost the local electron delocalization offers a promising route for improving the efficiency of artificial H2O2 photosynthesis.