The electrochemical deposition of Zn-Mn coating from choline chloride-urea deep eutectic solvent

Abstract

Electrochemical and microscopic techniques were used for the characterisation of Zn-Mn coatings electrodeposited from choline chloride-urea deep eutectic solvent. Cyclic voltammograms show that there was no discernible Mn reduction peak when only Mn2+ was present in DES solution. The distinct Mn peak developed only upon addition of Zn2+ to the solution, probably due to previous Zn nucleation on the steel substrate. It was found that 22-27 wt-% Mn deposited at current densities of 3-8 mA cm(-2), amounts significantly higher than those obtained from aqueous electrolytes. Since higher deposition current densities resulted in the formation of a porous surface consisting of clusters of nodular crystallites, the optimal deposition c.d was determined to be 3 mA cm(-2).