Electrodeposition of composition controllable Zn[sbnd]Ni coating from water modified deep eutectic solvent

Abstract

Because of the anomalous co-deposition, the preparation of Ni content controllable ZnNi sacrificial coatings with excellent corrosion resistance from aqueous solutions is a great challenge. In this paper, a novel method was developed to deposit Ni content controllable ZnNi coating by adding appropriate water (0–7 wt%) to the deep eutectic solvent. It was found that the electrochemical windows of ChCl-2urea deep eutectic solvent were nearly unchanged when the water content was <5 wt%. The Ni content in ZnNi alloy can ranged from ~96 wt% to ~4 wt% by regulating the water content and deposition potential. The Zn alloy coating with ~14 wt% Ni and single γ phase exhibited the best protective effects to carbon steel, which was deposited from reline-5 wt% water at −1.2 V. Deep eutectic solvent-water system provides a promising way of preparing ZnNi alloy coatings with controlled composition and excellent corrosion resistance.