A study by voltammetry and the photocurrent response method of copper electrode behavior in acidic and alkaline solutions containing chloride ions

Abstract The electrochemical behavior of Cu electrodes in Cl − solutions was studied in a wide range of pH. The results were compared with those obtained in solutions containing F − , Br − , I − and So 2− 4 ions at pH 8.5, and discussed in terms of the competitive formation of Cu 2 O and CuCl films on the Cu surface and the influence of CuCl on the properties of Cu 2 O. At pH 8.5 or higher, Cu 2 O was formed first, whereas at pH 5.7 or lower the Cu 2 O film was formed on the Cu surface under the CuCl layer which was formed initially. It is believed that the Cu 2 O films doped with Cl − ions exhibited poor protective properties against Cu corrosion.