Fragmented Polymetric Carbon Nitride with Rich Defects for Boosting Electrochemical Synthesis of Hydrogen Peroxide in Alkaline and Neutral Media

Electrocatalytic oxygen reduction reaction via 2e- pathway is a safe and friendly route for hydrogen peroxide (H2O2) synthesis. In order to achieve efficient synthesis of H2O2, it is essential to accurately control the active sites. Here, fragmented polymetric carbon nitride with rich defects (DCN) is designed for H2O2 electrosynthesis. The multi-type defects, including the sodium atom doping in six-fold cavities, the boron atom doping at N-B-N sites and the cyano groups, are successfully created. Owing to the synergistic effect of these defects, the fragmented DCN achieves a high H2O2 yield of 2.28 mol gcat.-1 h-1 and a high Faradic efficiency of nearly 90% in alkaline media at 0.4 V vs. RHE in H-type cell. In neutral media, the H2O2 concentration produced by DCN can reach 1815 mM within 6 h at a potential of 0.2 V vs. RHE, and the H2O2 production rate of DCN is 0.23 mol gcat.-1 h-1. In addition, DCN shows excellent long-term durability in alkaline and neutral media. This study provides a new approach for the design and development of the boron, nitrogen doped carbon-based electrocatalysts for H2O2 electrochemical synthesis.