Electrosynthesis of ternary nonprecious Ni, Cu, Fe oxide nanostructure as efficient electrocatalyst for ethanol electro-oxidation: Design strategy and electrochemical performance

Abstract

Materials composed of various constituents with distinct physical or chemical features are named composites. Merging components in the composite structure leads to new properties creation or the intrinsic properties magnification of the components, or synergetic effects. Here, the ternary nanocomposite of copper, nickel, and iron oxides was electrodeposited on the glassy carbon electrode (GCE) surface to facilitate the ethanol electro-oxidation reaction (EOR) and overcome the electrode fouling problem while prolonging its efficiency. The GCEs were modified by three different procedures and activated by CV cycling in an alkaline solution, and their electro-catalytic activity was tested toward EOR. The ternary electrocatalysts prepared by two-steps electrodeposition of their components (Ni,Fe2O3/Cu and Cu/Ni,Fe2O3) demonstrated higher peak current and more negative peak potential (Epa = 476 mV, Ipa = 492 μA, and Epa = 510 mV, Ipa = 644 μA, respectively) than the binary electrocatalyst of Ni,Fe2O3 toward EOR. The best electro-catalytic efficiency was acquired for the simultaneous electrodeposition of nano Cu, Ni, and Fe2O3 on the GCE surface (Cu,Ni,Fe2O3, Epa = 530 mV, Ipa = 3179 μA). The physicochemical and electro-catalytic characterizations of the fabricated electrocatalysts were evaluated by various techniques. The fast and facile engineered design of the GCE modification with the ternary Cu,Ni,Fe2O3 components led to a high current density of about 101 mA/cm2 with increased tolerance against poisoning intermediates resulting in longtime stability for EOR in alkaline media. The synergistic effect between nano Ni, Cu, and Fe oxides provided promising properties for the EOR pursuing the construction of a powerful device with commercialization potential.