Mass transfer and mechanism of electrochemical reduction of copper(II) from aminoacetate electrolytes

The paper presents calculated and experimental data on the determination of the ionic composition of an aminoacetate (glycine) electrolyte for copper plating in the bulk electrolyte and in the cathode layer over a wide pH range. The discharge mechanism of complexes of copper(II) with aminoacetate has been studied using voltammetry and chronopotentiometry. It has been shown that in an acid medium, hydrated copper ions and the CuGl+ complex and in a neutral medium the CuGl2 complex are discharged (Gl−=glycine). In an alkaline medium, the discharge of ions is a complicated process and depends on the potential and concentration of the alkali. At low polarization values, an oxide film is formed on the cathode surface, and at high polarization values all copper complexes are discharged directly to metal.