Defective NiS 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 NiS nanowires (NWs), which show high activity towards electrochemical oxidation of ethanol to acetate. The NiS 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 mAmg at 1.5 V are achieved using the synthesized NiS NWs toward the ethanol electro-oxidation, which are better than the Ni(OH) NWs and the NiS nanoparticles (NPs). And the selectivity for the acetate generation is ca. 99%. The high activity of NiS 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 NiS NWs structure as the efficient non-noble metal electrocatalysts for oxidative upgrading of ethanol. [Figure not available: see fulltext.]