Defective Ni₃S₂ nanowires as highly active electrocatalysts for ethanol oxidative upgrading

Electrochemical upgrading of biomass ethanol to value-added chemicals is promising for sustainable society. Here, we synthesize defective Ni₃S₂ nanowires (NWs), which show high activity towards electrochemical oxidation of ethanol to acetate. The Ni₃S₂ NWs are formed by the oriented attachment mechanism, and rich defects are introduced during the growth. A low onset potential of 1.31 V and high mass activity of 8,716 mA·mg_Ni⁻¹ at 1.5 V are achieved using the synthesized Ni₃S₂ NWs toward the ethanol electro-oxidation, which are better than the Ni(OH)₂ NWs and the Ni₃S₂ nanoparticles (NPs). And the selectivity for the acetate generation is ca. 99%. The high activity of Ni₃S₂ NWs is attributed to the easier oxidation of Ni(II) to the catalytically active Ni(III) species with the promotion from S component and rich defects. These results demonstrate that the defective NWs can be synthesized by the oriented attachment method and the defective Ni₃S₂ NWs structure as the efficient non-noble metal electrocatalysts for oxidative upgrading of ethanol.