Pyranoid-O-dominated graphene-like nanocarbon for two-electron oxygen reduction reaction

Abstract

Exploring the high-efficient two-electron oxygen reduction reaction (2e– ORR) catalysts is greatly significant for promoting hydrogen peroxide (H2O2) electroproduction. Herein, we have constructed a pyranoid-O-dominated graphene-like nanocarbon (GLC) material with high surface area, hierarchical porous structure, and abundant edge defects, through the high-temperature alkali activation of cellulose-based precursor. Benefiting from its integrated merits, the GLC electrocatalyst exhibits excellent 2e– ORR performance with high H2O2 productivity and ultrafast wastewater degradation ability. Interestingly, whether changing the carbonaceous precursor or alkali activator, all the as-prepared pyranoid-O-dominated GLC-based materials display high 2e– selectivity for the ORR. Based on further analogical experiments and theoretical analysis, the results reveal that the nature of 2e– selectivity on carbon-based materials is highly associated with the pyranoid-O dopants, rather than the surface oxygen-containing functional groups declared by the previous reports. These findings may bring new insight into the 2e– ORR selectivity of carbon-based electrocatalysts for H2O2 production.