Abstract
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•Yolk-shell B/N-HCNS@VO-G enables a selective and durable two-electron oxygen reduction reaction process.•High-yield electrosynthesis of H2O2 is realized by our dual-defective B/N-HCNS@VO-G.•Electro-synthetic H2O2 with oxidizing ability allow the on-site degradation of organic pollutants.•VO-G armor is proven to enhance both catalytic activity and durability of B/N-HCNS.
Electrocatalytic 2e− oxygen reduction reaction (ORR) strategy for decentralized and on-demand production of H2O2 has emerges as an appealing alternative to prevailing anthraquinone process. Nevertheless, the sustainable development of high-performance and low-cost electrocatalysts with high selectivity and durability remains elusive. Herein, we report a metal-free electrocatalyst affording B/N co-doped yolk-shell carbon nanosphere with oxygen-vacancy-decorated graphene armor (B/N-HCNS@VO-G) toward promoted 2e− ORR in alkaline media. Such a dual-defective electrocatalyst harvests excellent H2O2 electrosynthesis performance with a high selectivity of 91 % and a stable operation of 24 h, which is markedly superior to its counterparts and compares favorably with the state-of-the-arts. Density functional theory calculations further reveal the essential roles of defective graphene coating played in advancing the 2e− ORR selectivity of B/N-HCNS@VO-G. More impressively, thus-produced H2O2 (realizing a high yield of 56 ppm at 0.7 V) satisfies an in-situ antibiotic and dye degradation, holding practical promise for on-site wastewater remediation.