Study of the electrochemical co-reduction of Cu2+ and Zn2+ ions from an alkaline non-cyanide solution containing glycine

The electrochemical deposition of Cu–Zn alloy was studied in weakly alkaline glycine solutions at pH 10.0 and room temperature. This study was realized by cyclic voltammetry, chronoamperometry, scanning electron microscopy, energy dispersive X-rays and atomic absorption spectrometry. Voltammetric studies displayed three cathodic and anodic peaks, respectively, for Cu–Zn alloys. ALSV profiles showed different oxidation peaks for dissolution of the deposits of Cu–Zn alloy and these had shapes which depend on the conditions of electrodeposition. The dissolution peaks do not coincide with peak potential for the dissolution peak of pure copper and zinc. The physical and chemical characterization of these coatings showed to be interrelated, meaning that the chemical composition, cathodic current efficiency and surface morphology of Cu–Zn alloys obtained were found to be depending on the electrolyte composition and applied potential. AAS analysis revealed the presence of mainly copper, which suggests that the process of formation of Cu–Zn alloy can be classified as normal (irregular) solution.