Electrodeposition of aluminium from hydrophobic perfluoro-3-oxa-4,5 dichloro-pentan-sulphonate based ionic liquids

The viability of aluminium electrodeposition was, at first, tested on vitreous carbon, demonstrating it follows through a nucleation and growth process. As the practical interest carries to the use of metallic substrata, nickel was selected to analyse deposition process. The deposits prepared at constant current showed a better appearance, less stressed and smoother than the ones prepared at constant potential. The effect of temperature and concentration was studied in solutions prepared with tetramethyl guanidinium-perfluoro-3-oxa-4,5 dichloro-pentan-sulphonate, taking advantage of its immiscibility in water. Deposits prepared from the lower concentrations tested (AlCl3:IL 0.95:1 molar ratio) were continuous, fine grained and stress-free, provided that they were obtained at moderate applied current. From higher Al(III) concentration solutions it was only possible to allow stress-free deposits by applying low currents.