Effect of Highly Concentrated Perchlorate in Aqueous–Acetonitrile Electrolytes on the Deposition Kinetics and Quality of Cadmium Coatings

Abstract

Substantial adsorption of perchlorate anions at a Cd cathode and the participation of adsorbed complexes of Cd2+ with acetonitrile (AN) in the electrode reaction are shown to facilitate the formation of ionic associates in the surface layer. The associates inhibit cadmium electrodeposition and promote the formation of coatings of higher quality (adhesion, microhardness, corrosion resistance, etc.). The effect of the anions is most pronounced in the domain of ordering the AN structure (0.75 ≤ x 2≤ 0.95), where the adsorption of ClO– 4 on Cd reaches the maximum.