Surface modification of glassy carbon electrode by Ni-Cu nanoparticles as a competitive electrode for ethanol electro-oxidation

Abstract

In the present study, Nickel-Copper nanoparticles were electrodeposited on glassy carbon electrode (GCE) by using electroplating deposition method. The prepared electrode was characterized by scanning electron microscopy (SEM) and elemental mapping analysis. Results showed that Ni-Cu nanoparticles with a high density are distributed at the surface of the glassy carbon electrode. Subsequently, this electrode was applied for ethanol electro-oxidation using cyclic voltammetry (CV), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS) techniques. The results of voltammograms showed high catalytic activity, increased the oxidation peak current density at the low potential for ethanol electrooxidation on Ni-Cu/GCE. Study of the electro-oxidation mechanism by the effect of scan rate for ethanol on Ni-Cu /GCE indicated that the oxidation process is controlled by diffusion processes. Chronoamperometric measurements illustrate that Ni-Cu/GCE exhibits a steady state activity for ethanol electro-oxidation. EIS measurements showed that the diameter of semi-circle for Ni-Cu/GCE is greatly smaller than the bare GCE. The modified electrode is a good candidate as an anode for application in direct ethanol alkaline fuel cells.