Nano-sized aluminum coatings from aryl-substituted imidazolium cation based ionic liquid

The present paper discusses the electrodeposition of nano-Aluminum using aromatic cation based ionic liquids. Three imidazolium chloride salts were employed, in ultrapure quality: l-ethyl-3-methyl-imidazolium chloride [EMIm]Cl, l-benzyl-3-methyl-imidazolium chloride [BzMIm]Cl and l,3-dibenzyl-imidazolium chloride [DBzIm]Cl, respectively. Anhydrous Aluminum chloride (AlCl3) salt was used as a source of Aluminum ions in the ionic liquids. This research aims to achieve this goal by investigating the Aluminum coatings on gold substrate and study the effect of changing the organic cation on the properties of the resulting Al-coatings. SEM-EDAX analyses were used to determine the film composition. It was found that the particle size of the Al-deposites was dramatically reduced from the micrometer regime down to the nanometer regime with a change in the substituents of the imidazolium cations from EMIm to DBzIm, respectively. This means that the more the aromatic rings in the cation, the finer the particle size. Thickness and adhesion of the Al-deposits were decreased in the presence of the aromatic rings.