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

Abstract

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 0.57V with high selectivity of over 92% across the wide potential range from 0.6 to 0V. 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.