Electrochemistry and galvanic deposition of group 10 & 11 transition metals using deep eutectic solvents

The galvanic deposition of metals has wide ranging applications in many industries. One example is the printed circuit board industry, where galvanic coatings are used as both a catalyst for the activation of the surface of a substrate and protective coating to prevent the oxidation of the surface. Deep Eutectic Solvents (DESs) have received growing interest in the area of metal processing, due to the unique solvation properties and ability to dissolve metal salts, without the need for addition of acids or bases. The DESs have been widely applied in electrochemical processes, where electrochemistry can be performed without the need for addition of an electrolyte. In this work, the speciation of the group 10 and 11 metals has been characterised using UV – Vis spectroscopy. The electrochemistry of the group 10 and 11 elements has been characterised using cyclic and linear sweep voltammetry and related to the speciation of the metal centres. Further characterisation of the electrochemistry was performed using an electrochemical quartz crystal microbalance, allowing for the rate and current efficiency of the electrochemical reaction to be measured. Galvanically deposited coating of group 10 and 11 metals, were produced on a standardised copper substrate. The morphology of the coatings was characterised by atomic force (AFM) and scanning electron microscopy (SEM) and the composition by energy dispersive X – ray (EDX) and X – ray photoelectron spectroscopy (XPS). The mechanism by which the galvanic coatings are formed was probed. The reaction mechanism was predicted from the formal electrode potential of the metal redox couples. The predicted mechanisms were experimentally investigated using quartz crystal microbalance experiments. The quartz crystal microbalance also allowed for the determination of the rate of the galvanic reactions.