Electrodeposition of palladium films from ionic liquid (IL) and deep eutectic solutions (DES): physical-chemical characterisation of non-aqueous electrolytes and surface morphology of palladium deposits

The physical and electrochemical characteristics such as density, viscosity, electrical conductivity and cyclic voltammetry of three different non-aqueous palladium electrolytes were analysed. The cyclic voltammetry behaviour showed typical reduction and oxidation peaks corresponding to the deposition and stripping of palladium in the electrolytes employed. The electrodeposition of palladium films from choline chloride/ethylene glycol (ChCl-EG), choline chloride/urea (ChCl-urea) and 1-butyl-3-methylimidazolium chloride-tetrafluoroborate (BMIM-Cl-BF4) solutions was demonstrated. Compact deposits were obtained with galvanostatic electrolysis. The scanning electron micrographs of the deposits revealed predominantly nodular Pd particles.