Quality and Efficiency Control of Electrodeposition and Electrodissolution of Ni on a Ternary Composite Electrode Followed by Digital Video Electrochemistry

Abstract

The quality of metal electrodeposits on different surfaces depends on the configuration and composition of the electrochemical bath, but also on the control of experimental variables that can affect the electrode processes taking place. In this work, we have studied the electrodeposit of nickel on a polypropylene|graphite|copper (PP|G|Cu) ternary composite electrode. Together with the resistive behavior of the electrode, the nickel electrodeposition presents extra difficulties as a low reduction potential and numerous and possible chemical reactions with the medium to form passive layers or aqueous complexes. The use of digital video electrochemistry (DVEC) has allowed detecting some issues during the electrodeposition and electrodissolution processes such as the non-uniform growth of Ni due to the electrode configuration, secondary and oscillatory electrochemical reactions caused by the subproducts in the auxiliary electrode or the effect of the formation of hydrogen bubbles. The estimation of electrodeposition efficiency from DVEC and a possible electrodissolution mechanism are discussed.