Mesoporous carbon-doped boron nitrides for cathodic and anodic hydrogen peroxide electrosynthesis

Abstract

Mesoporous carbon-doped hexagonal boron nitrides (C-doped BN) with high surface area were prepared by annealing organic resin polymer/silica in NaBH₄ and NaNH₂ inorganic salts, which were found to be efficient metal-free bifunctional electrocatalyst for both 2e⁻ ORR and 2e⁻ WOR. It could efficiently catalyze 2e⁻ ORR to H₂O₂ in 2 M KHCO₃ (1650 mmol g⁻¹ h⁻¹) with Faraday efficiency of 93–98 % in half reaction, while it was very active for 2e⁻ WOR to generate H₂O₂ in 2 M KHCO₃ with 551 mmol g⁻¹ h⁻¹ H₂O₂ production rate in half reaction. When pairing them in one H-type cell, H₂O₂ solution could be totally produced over C-doped BN in both anode and cathode cells. The better electron conductivity from sharper band gap caused by carbon doping and higher surface area of 304 m² g⁻¹ contributed to its efficient electrocatalytic activity. The C-doped BN served an effective bifunctional electrocatalyst for 2e⁻ ORR and 2e⁻ WOR.