Electrocatalytic Oxidation of Ethanol and Ethylene Glycol onto Poly (o-Anisidine)-Nickel Composite Electrode

Abstract

<em>In this work, poly (o-Anisidine) (POA) was prepared by consecutive potential cycling in an acidic monomer solution at the surface of Carbon Paste Electrode (CPE). Nickel ions were dispersed into the polymer by immersing the electrode in NiSO₄ solution. The prepared Ni/POA/CPE was characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, Atomic Force Microscopy (AFM) and electrochemical methods. The electrochemical oxidation of ethanol and ethylene glycol was investigated at the Ni/POA/CPE by cyclic voltammetry and chronoamperometry techniques. The results indicated that the Ni/POA/CPE in comparison with Ni/CPE exhibited excellent electrocatalytic activity towards oxidation. Then, using a chronoamperometry method, the catalytic rate constant, k, for ethanol and ethylene glycol oxidation were found to be 2.6×10⁶ and 1.07×10⁷ cm³/mol s, respectively. Furthermore, the effect of several parameters such as OA concentration, POA thickness, and NiSO₄ concentration and accumulation times towards the ethanol oxidation as well as the long-term stability of the modified electrode has been investigated.</em>