A Comparative Study of Nickel Electrodeposition Using Deep Eutectic Solvents and Aqueous Solutions

Abstract

Graphical Abstract Highlights: Facile electro-deposition of bright Ni is possible from DES electrolytes at elevated temp. and high concentration. Harder Ni deposits are obtained from DES than from aqueous electrolytes. Similar deposition rates are measured despite the higher viscosity of the DES. AbstractMetal electrodeposition using ionic liquid electrolytes and deep eutectic solvents is now well known but to our knowledge for electrolytic deposition of metals such as nickel no direct comparison has thus far been drawn between deposition using aqueous solutions and DES under otherwise identical conditions. In the current study it is shown that nickel deposition can be carried out with similar deposition rates in aqueous and ionic media despite the significant differences in viscosity and conductivity. It is, however, shown that in ionic media the morphology of the deposits is markedly different from that achieved using a Watts nickel bath and that one aspect of these differences manifests itself in significant increase in the coating hardness. It is proposed that the observed morphology differences occur due to the variations of nickel speciation in each electrolyte environment.

Bright metal coatings from sustainable electrolytes: the effect of molecular additives on electrodeposition of nickel from a deep eutectic solvent

“…29 Typically, the speciation of a metal salt in an IL is dominated by either the counter ion of the dissolved metal salt and/or the anion component of the ionic liquid 30,31 unless additional ligands are included in the formulation. 32 Despite the increasing complexity in the 34 This temperature behaviour (change in colour) is evidenced by the evolution of UV-visible absorbance spectrum shown in Figure 1. The black line in Figure 1 (a) shows the UV-visible spectrum for a 15 mM solution of NiCl 2 in Ethaline at room temperature.…”

“…In the previous example plating was onto an Ni substrate, the concentration of Ni was higher (1.1 M) and the plating times longer, all factors that will affect deposition behaviour and hence quality of the resulting coatings. 34 An image of the coating produced under the conditions described here, where no additives are present in the plating solution, is shown in Figure 7 (a). Here, a dull, dark grey friable Ni coating covers the surface of the copper substrate.…”

“…34,35 At low temperatures and concentrations there are no discernible deposition and stripping responses during cyclic voltammetric scans. However, once the temperature and concentration is increased towards and above 80 °C a quasi-reversible deposition/stripping electrochemical response is observed.…”

Electrochemistry and speciation of Au+in a deep eutectic solvent: growth and morphology of galvanic immersion coatings

“…18 These liquids have widespread appeal in the electrochemical, synthetic and polymer fields due to their low toxicity, they are air and moisture stable and are easily prepared in high purity. 15 We have previously demonstrated a variety of electrolytic coatings including Ni, 19 Cu, Cr, Ag, Sn and Zn at high current efficiency. 20 In addition, an immersion Ag deposition onto copper 10 as an alternative PCB surface finish was studied, including scale up to pilot plant scale, demonstrating its suitability for the industrial production of PCBs.…”

Electrodeposition of Antimony from Hydrated Ammonium Aluminum Sulfate-Urea Room Temperature Ionic Liquid

“…This is an interesting characterization as added water to anhydrous ionic liquid of NiCl 2 :urea showed to influence the nature of deposited nickel [11].…”