Highly Efficient Electrosynthesis of H2O2 by Heteroatom-Doped Carbon Nanosheets for In Situ Sterilization

Abstract

Oxygen reduction reaction (ORR) provides a green alternative route for the efficient production of H₂O₂. It is important to enhance the environmental safety and compliance with the Sustainable Development Goals. Herein, we report a heteroatom-doped reduced graphene oxide (rGO-N/rGO-S/rGO-SN) catalyst, among which rGO-N exhibits good two-electron catalytic performance in a simulated seawater (3.5% NaCl). The rGO-N has higher activity under neutral conditions while maintaining a high H₂O₂ selectivity of 70%. The rGO-N presents an attractive H₂O₂ production amount up to 300 mmol/g/h at a −1.1 mA/cm² current density. The remarkable electrocatalytic activity of rGO-N is attributed to the doping of heteroatom nitrogen changing the electronic structure of the material, which makes it easier for the 2e^– process. Meanwhile, the H₂O₂ selectivity of rGO-N could still reach 45% in natural seawater with complex ions. Interestingly, it was found that the chloride ion promotes the H₂O₂ selectivity of 2e^– ORR. Antibacterial experiments were conducted on the H₂O₂ generated by electrocatalysis in an H-type electrolytic cell. It was found that the sterilization rate during the electrocatalytic process could reach as high as 99% within 30 min in simulated seawater, indicating great potential of the catalyst for future practical applications such as green, effective antibacterial and antifouling in the marine environment.