Effect of the Sulphuric Acid Concentration on the Silver Ion Cementation on Copper

The effect of sulphuric acid concentration on the kinetics of silver ion cementation on copper in the electrolyte containing 0.5 M CuSO4 was investigated at 25 oC at a rotating cylinder system. The morphology of the silver deposit cemented in the presence or absence of oxygen was studied. Additionally, the influence of the concentration of H ion on the mechanism of the cementation, proposed by Khudenko et al., was verified. It was found that various concentration of sulphuric acid neither change the kinetics of the cementation nor the mechanism of process conducted in deoxygenated and oxygenated solutions. The increasing concentration of H ion does not enhance the silver cementation on copper as was proposed by Khudenko. The decreasing concentration of sulphuric acid in the electrolyte used for cementation promotes only the deposition of less-adhesive silver cement on copper. This study showed clearly that the Khudenko’s mechanism of cementation is highly doubtful. The mechanism of silver ion cementation on copper in acidic copper sulphate solutions is strongly determined by the presence of the oxygen in the system.