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 (HO) synthesis. In order to achieve efficient synthesis of HO, it is essential to accurately control the active sites. Here, fragmented polymetric carbon nitride with rich defects (DCN) is designed for HO 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 HO production rate of 2.28 mol g  h 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 HO concentration produced by DCN can reach 1815 μM within 6 h at a potential of 0.2 V vs. RHE, and the HO production rate of DCN is 0.23 mol g  h. In addition, DCN shows excellent long-term durability in alkaline and neutral media. This study provides a new approach for the development of the boron, nitrogen doped carbon-based electrocatalysts for HO electrochemical synthesis.