Corrosion resistance of CU 2 O and CuO on copper surfaces in aqueous media

Improvement of the corrosion resistance of copper has been accomplished by the deliberate formation of cuprous and cupric oxides on the metal surface, based on simple immersion in acetate buffer or sodium hydroxide solution. Weight loss, potentiodynamic, and potentiostatic polarisation measurements in sodium chloride, ammonia, and sodium bicarbonate solutions demonstrated that the presence of these oxides improved the corrosion resistance of copper considerably. The bicarbonate solution was also found to be a suitable medium for testing the stability of the oxide layers by the electrochemical methods. The presence of the oxide layer on copper surfaces was useful in improving its corrosion resistance in a Sydney tap water.