Electrochemical production of hydrogen peroxide by non-noble metal-doped g-C3N4 under a neutral electrolyte

Abstract

Electrochemical oxygen reduction (ORR) for the production of clean hydrogen peroxide (H₂O₂) is an effective alternative to industrial anthraquinone methods. The development of highly active, stable, and 2e⁻ ORR oxygen reduction electrocatalysts while suppressing the competing 4e⁻ ORR pathway is currently the main challenge. Herein, bimetallic doping was successfully achieved based on graphitic carbon nitride (g-C₃N₄) with the simultaneous introduction of K and Co, whereby 2D porous K–Co/CNNs nanosheets were obtained. The introduction of Co promoted the selectivity for H₂O₂, while the introduction of K not only promoted the formation of 2D nanosheets of g-C₃N₄, but also inhibited the ablation of H₂O₂ by K–Co/CNNs. Electrochemical studies showed that the selectivity of H₂O₂ in K–Co/CNNs under neutral electrolyte was as high as 97%. After 24 h, the H₂O₂ accumulation of K–Co/CNNs was as high as 31.7 g L⁻¹. K–Co/CNNs improved the stability of H₂O₂ by inhibiting the ablation of H₂O₂, making it a good 2e⁻ ORR catalyst and providing a new research idea for the subsequent preparation of H₂O₂.