Electrodeposition of CdZn coatings based on deep eutectic solvent

Cadmium-zinc alloy coatings were successfully electrodeposited on copper electrodes from a choline chloride-ethylene glycol deep eutectic solvent containing CdCl2 and ZnCl2. The electrochemical behaviour of the electrolyte system was investigated via linear sweep voltammetry, and the result revealed that the CdZn alloy was codeposited when the deposition potential was prolonged to the potential range, leading to the insufficient zinc deposition on the copper electrode. The scanning electron microscopy results demonstrated that the morphologies of codeposits were cauliflower-like. The codeposition mechanism was also investigated, and the dependencies of the Cd content in the CdZn codeposit on the deposition potential, Cd(II) molar ratio and temperature were discussed.