Electrodeposition of nickel using eutectic based ionic liquids

The electrolytic deposition of nickel is demonstrated using a solution of the metal chloride salt separately in either a urea or ethylene glycol/choline chloride based ionic liquid. It is shown that the deposition kinetics and thermodynamics differ from the aqueous processes and these result in different deposit morphologies. It is also shown for the first time that bright metal coatings can be obtained from these liquid systems by adding various brightening agents and deposits can be put directly onto substrates such as aluminium without prior treatment. The general mechanism by which brighteners function in ionic liquids is also discussed.