Analysis of the underpotential deposition of cadmium on copper

Abstract

In this study the process of deposition of cadmium on polycrystalline copper electrode in sulfate solution was investigated. The process of underpotential and bulk deposition was analyzed by classical electrochemical method: cyclic voltammetry(CV), anodic stripping voltammetry(ASV) and electrochemical quartz crystal microbalance(EQCM). The obtained results were compared with electrochemical impedance spectroscopy(EIS) measurements. CV, EQCM and EIS results suggest that the UPD of cadmium starts below potential -0.4 V vs Ag/AgCl. Additionally the stripping analysis indicates the formation of cadmium monolayer with different density of deposited atoms depending on the applied potential. The transition from UPD to bulk deposition occurs below potential -0,7 V.