Cyclic Voltammetric Behavior of Copper Powder Immobilized on Paraffin Impregnated Graphite Electrode in Dilute Alkali Solution

Cyclic voltammetric behavior of electrolytic grade copper powder immobilized on paraffin impregnated graphite electrode is studied in 0.1 M KOH solution. Few micrograms of copper powder is mechanically immobilized on the surface of paraffin impregnated graphite electrode and subjected to electrochemical characterization. Well separated, stable and sharp redox peaks for both Cu (I) and Cu (II) oxides are observed. Lowering the upper positive potential limit by increments of 5 mV is found to be directly proportional to the changes in the reduction peaks of both oxides which in turn is decided by the hydrous oxide film. In the absence of hydrous oxide film, the solid state redox transformations were stoichiometrically controlled and quasi reversible. This study helps to understand the 95-99 % efficiency of copper recovery process in our pilot plant.