Electrosynthesis of H₂O₂ Promoted by π-π Interaction on a Metal-Free Carbon Catalyst

The synthesis of hydrogen peroxide (H₂O₂) through electrocatalytic oxygen reduction reaction is an ideal alternative to the current energy-intensive anthraquinone process, but developing cost-effective and high-efficiency electrocatalysts is still challenging. Herein, a metal-free graphitic carbon nitride/carbon nanotube (g-C₃N₄/CNT) hybrid catalyst can enhance H₂O₂ production via π-π interaction is reported, achieving almost unity (97%) H₂O₂ production at 0.57 V with high selectivity of over 92% across the wide potential range from 0.6 to 0 V. Other carbon materials with weak interaction with g-C₃N₄, such as acetylene black and super P, show markedly weakened H₂O₂ production, indicating the importance of π-π interaction. Electron transfer kinetic analysis combined with density functional theory calculations indicates that the synergistic effect between g-C₃N₄ and CNT enhances electron transfer and O₂ activation between g-C₃N₄ and CNT, leading to enhanced H₂O₂ production performance. This work provides a complementary approach for H₂O₂ production from oxygen reduction besides introducing oxygenated groups or heteroatom doping into carbon materials.