Highly Efficient Electrosynthesis of H ₂ O ₂ by Heteroatom-Doped Carbon Nanosheets for In Situ Sterilization

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.