Electrodeposition of aluminium and aluminium/platinum alloys from AlCl3/benzyltrimethylammonium chloride room temperature ionic liquids

This paper shows that aluminium and aluminium/platinum alloys can be deposited from room temperature ionic liquids formed from an adduct of aluminium trichloride with benzyltrimethyl ammonium chloride. The advantages of this ionic liquid over the majority of those previously investigated is that it is less water sensitive, easier to purify and form and significantly more cost effective. Voltammetry and chronoamperometry were used to investigate the deposition and stripping of aluminium on Pt, Al and Fe electrodes. Hull cell tests were performed to obtain the optimum deposition conditions and bulk electrolysis showed that uniform, adherent, crack-free aluminium deposits could be obtained from such ionic liquids. Co-electrodeposition of Al with Pt was also studied and the nucleation mechanism was found to change significantly when Pt complexes were added to the ionic solution. The platinum ligands were found to change the solubility of the complex, but had little effect on the morphology of the deposited film.