Environmental application of chlorine-doped graphitic carbon nitride: Continuous solar-driven photocatalytic production of hydrogen peroxide.

Solar-driven photocatalytic generation of HO over metal-free catalysts is a sustainable approach for value-added chemical production. Here, we synthesized chlorine-doped graphitic carbon nitride (Cl-doped g-CN) through a solvothermal method to effectively produce HO with a rate of 1.19 ± 0.06 µM min under visible light irradiation, which was improved by 104 times compared to pristine g-CN. Continuous net production of HO was realized at a rate of 2.78 ± 0.10 µM min up to 54 h with isopropanol as the hole scavenger, whereas HO production was only sustained for ~ 6 h without scavengers. Both molecular simulations and advanced spectroscopic characterizations elucidated that the Cl dopant increased the charge transfer rate, decreased the bandgap, and reduced the activation energy of the rate-limiting step of O reduction, all of which favored HO production. This work implemented a novel metal-free photocatalyst for sustainable HO production and elucidated the mechanism for promoting HO production that can guide future photoreactive nanomaterial design.