Ethylene glycol assisted solvo-hydrothermal synthesis of NGr-Co_3O_4 nanostructures for ethanol electrooxidation

摘要

Different morphologies of Co3O4 nanostructures grown on nanographitic flakes have been synthesized based on the decomposition of cobalt acetate precursor in water, ethylene glycol and water (50%)-ethylene (50%) solution at 180 degrees C for 18 h via a solvo-hydrothermal process. A subsequent electrophoretic deposition process is used to form composite layers on stainless steel plates. The composite layer fabricated in the water (50%)-ethylene (50%) solution is found to have the best electrocatalytic performance for ethanol electrooxidation due to the hierarchical nanoporous microstructures of Co3O4 exhibiting the lowest onset voltage for ethanol electrooxidation (around -0.3 V vs. Ag/AgCl) among the fabricated electrocatalyst layers. Moreover, the ethanol electrooxidation current for the electrode fabricated in the water (50%)-ethylene glycol (50%) reaches roughly 6.6 mA/cm(2), while it is about 3.3 mA/cm(2) at 0.5 V (vs. Ag/AgCl) for the electrode fabricated in pure ethylene glycol values obtained after 1-h stability tests). The electrode fabricated in pure water is confirmed to not exhibit significant ethanol electrooxidation. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.