A STUDY BY VOLTAMMETRY AND THE PHOTOCURRENT RESPONSE METHOD OF COPPERELECTRODE BEHAVIOR IN ACIDIC AND ALKALINE-SOLUTIONS CONTAINING CHLORIDE-IONS

The electrochemical behavior of Cu electrodes in Cl- solutions was stu died in a wide range of pH. The results were compared with those obtai ned in solutions containing F-, Br-, I- and SO42- ions at pH 8.5, and discussed in terms of the competitive formation of Cu2O and CuCl films on the Cu surface and the influence of CuCl on the properties of Cu2O . At pH 8.5 or higher, Cu2O was formed first, whereas at pH 5.7 or low er the Cu2O film was formed on the Cu surface under the CuCl layer whi ch was formed initially. It is believed that the Cu2O films doped with Cl- ions exhibited poor protective properties against Cu corrosion.