Facile electrolysis-solvothermal synthesis of NiOx/graphene for enhanced ethanol oxidation to acetate

Abstract

In this work, low-crystalized and defective NiO_x/graphene was synthesized by a facile electrolysis-solvothermal method. In the electrolytic process, Ni ions originate from the Ni anode, and graphene is produced from the graphite cathode. Then, Ni ions are reduced into oxides and deposited on graphene in the subsequent solvothermal process. The NiO_x/graphene displays excellent electrocatalytic activity and selectivity for ethanol oxidation reaction to acetate. The peak current density was 296.5 mA cm⁻² on a glassy carbon electrode. The FE of acetate was more than 93% at the potential range between 1.4 and 1.7 V. We propose that the mechanism is a cooperation between the chemical deprotonating process of ethanol by Ni³⁺ species and the electrochemical oxidation of the CH₃CH₂O* intermediate to acetate at the interface between NiO_x and graphene.