Harnessing selective and durable electrosynthesis of H2O2 over dual-defective yolk-shell carbon nanosphere toward on-site pollutant degradation.

[Display omitted] • Yolk-shell B/N-HCNS@V O -G enables a selective and durable two-electron oxygen reduction reaction process. • High-yield electrosynthesis of H 2 O 2 is realized by our dual-defective B/N-HCNS@V O -G. • Electro-synthetic H 2 O 2 with oxidizing ability allow the on-site degradation of organic pollutants. • V O -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 H 2 O 2 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@V O -G) toward promoted 2e− ORR in alkaline media. Such a dual-defective electrocatalyst harvests excellent H 2 O 2 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@V O -G. More impressively, thus-produced H 2 O 2 (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. [ABSTRACT FROM AUTHOR]