Synergy of sodium doping and nitrogen defects in carbon nitride for promoted photocatalytic synthesis of hydrogen peroxide

Photocatalytic synthesis of hydrogen peroxide has gradually become a promising method for in-situ production of hydrogen peroxide, which relies on sustainable solar energy. However, the commonly used photocatalyst, i.e., carbon nitride (CN), still suffers from the drawbacks of narrow light absorption range and fast charge recombination. Here, we report a facile method to introduce nitrogen defects into carbon nitride together with sodium ion. By adjusting the ratio of sodium dicyandiamide, the band gap of carbon nitride can be controlled, while the carrier separation and transfer ability of carbon nitride is improved. The modified CN with sodium doping and nitrogen defect (SD-CN) demonstrates outstanding H2O2 production performance (H2O2 yield rate of 297.2 µmol L−1 h−1) under visible light irradiation, which is approximately 9.8 times higher than that of pristine CN. This work deepens the understanding of the coordinated effect of structural defect and element doping of carbon nitride on the photocatalytic H2O2 production performance, and provides new insight into the design of photocatalytic system for efficient production of H2O2.