Electrochemical behavior of copper electrode in sodium hydroxide solutions

I. Zaafarany,H. Boller

doi:10.12944/cwe.4.2.32

Abstract

The cyclic voltammograms of the copper electrode in different concentrations of NaOH solutions was studied using cyclic voltammogram's (CV's) technique. In addition surface examination and morphological studies were also conducted using scanning electron microscope (SEM) and energy dispersive analysis of X-rays (EDAX). The four anodic peaks where founds to correspond successively to the formation of a mono layer of Cu 2 O, a thick layer of CuO and CuO 2 2- and finally the formation of a higher oxide Cu2O3 before the evolution of oxygen. It is suggested that the CuO is formed from the oxidation of Cu 2 O and/or direct oxidation of metallic copper in 5M NaOH solution. The ratio of anodic and cathodic charge was found to be about unity, indicating the quantitative reduction of solid oxidation product. The behavior of copper electrode in NaOH solutions was found to be quite complicated. Thus, no simple relation were found between the voltage scan rate and both the peak current and peak potential or between the peak K current and alkali concentration of alkali.

Highlights

The electrochemical behaviour of copper is of considerable interest in many areas of technology, including solar cell[1], integrated circuits[2] and heat exchangers[3]
Surface Analysis The thin layer formed after immersion of copper electrode in 5M NaOH solution was investigated by scanning electron photomicrographs energy dispersive analysis of X-ray (EDAX)
The cyclic voltamograms of the copper electrode where obtained in NaOH solution as a function of the electrolyte concentration and voltage range

Summary

Introduction

The electrochemical behaviour of copper is of considerable interest in many areas of technology, including solar cell[1], integrated circuits[2] and heat exchangers[3]. The anodic behaviour of Copper in alkaline environments leads to the formation of an oxide film consisting of either Cu2O or a duplex layer of Cu2O and CuO depending on the electrolyte composition and electrochemical conditions[8,9,10]. 1- Effect of alkali concentrations The electrochemical behavior of copper in alkaline solutions was studied using cyclic voltammograms technique (CV’s).

Results

Conclusion