Abstract
Vinasse has been successfully used as carbon and non-metals precursor for the synthesis of N-S-doped nanoporous carbon materials. The procedure involves the hydrothermal treatment of vinasse (HTV), and subsequent physical activation with CO2 in absence (VP) and presence of cobalt (VPCo). The N2 physisorption and SEM images showed the development of porous in the material, with BET surface area values ranging from 7.17 (HTV) to 734 m2 g−1 (VPCo), and the formation of carbon-spheres. Spectroscopy techniques (FTIR and XPS) demonstrated the insertion of nitrogen and sulfur elements, as well as the presence of cobalt into the carbon lattice. The electrocatalytic activity experiments toward the oxygen reduction and evolution reactions, and hydrazine oxidation reaction were superior for VPCo, which gave onset values of 0.91, 1.60 and 0.36 V vs. RHE, respectively. Additionally, VP was selective for H2O2, while VPCo catalyzed ORR via a four-electron pathway.
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•Sugarcane vinasse was successfully converted into carbon via hydrothermal treatment.•The vinasse acted both as carbon and non-metal precursor (nitrogen and sulfur).•CO2-physical activation enhanced the porosity of the materials.•Selective materials toward H2O2 production and total O2 reduction were prepared.•Decorated the material with cobalt improved its activity toward all reactions.