Ni_xCo_(3-x)O4 nanowire arrays grown on carbon fiber cloth as efficient electrocatalysts for urea oxidation

摘要

Three-dimensional Ni_xCo_(3-x)O4 nanowire arrays (NWAs) grown on carbon fiber cloth (CFC) are successfully fabricated by a simple hydrothermal method combined with a post annealing treatment, which are directly applied as binder-free electrodes for urea oxidation reaction (UOR). Remarkably, the Ni1.5C01.5O4 NWAs/CFC sample shows much higher catalytic activity, lower overpotential, better stability towards urea electro-oxidation compared to NiO synthesized by the similar procedure. The Ni_(1.5)Co_(1.5)O4 electrode delivers a current density of 98.5 mA cm~(-2) mg~(-1) at 0.45 V (vs. Ag/AgCl) in 1 M KOH and 0.33 M urea electrolyte after 8-hour test. These nickel cobalt oxides electrodes with advanced architecture and desirable catalytic performance show great potential for the applications of urea electro-oxidation, including wastewater remediation, hydrogen production, sensors, and fuel cells.