Electrodeposition of Nanocrystalline Nickel Coatings from a Deep Eutectic Solvent with Water Addition

Effect of water on the electrodeposition of copper from a deep eutectic solvent

“…Over the same range of water concentrations, the viscosity of the copper containing ethaline was reduced from 47.3 to viscosity than for pure ethaline. Comparable trends in viscosity have been reported in earlier studies [8,14,16,30,31] when water is added to pure reline and ethaline and type-III eutectics formulated from hydrated metal chloride salts.…”

“…As already noted, DES formulations have a relatively low conductivity ( < 1 S m -1 ) compared to typical aqueous systems (  10 -50 S m -1 ) [2,3]. As with viscosity, improvements can be attained by operating at higher temperatures [16,31], but using water as a co-solvent is a more cost effective alternative [16,30,31]. For example, Fig.…”

“…A lower viscosity DES is desirable in electrodeposition systems as it strongly influences both the conductivity and mass transport characteristics. The viscosity of DES decreases can be increased by increasing temperature [3,16] but an alternative way is to introduce a co-solvent such as water [16,30,31]. The latter approach has advantages in terms of reduced energy consumption, although either method is potentially viable in practical plating situations.…”

The role of hydrogen bond donor and water content on the electrochemical reduction of Ni2+ from solvents – an experimental and modelling study

“…Among the several technologies that aim to use DESs as a replacement for aqueous solutions and RTILs, the electrochemical deposition of reactive and transition metals is among the most investigated 7,8,35,36 . However, taking the electrodeposition of nickel from DES-water mixtures as an example, the influence of H 2 O in the process remains under discussion despite many recent studies on the topic 21,24,25,[37][38][39] . It has been shown that the presence of small amounts of water (up to 6 wt%) seems to be beneficial for electroplating as it may increase the conductivity and decrease the viscosity of the solvent 14,16,21,38 .…”

Influence of water content and applied potential on the electrodeposition of Ni coatings from deep eutectic solvents

“…On the one hand, the presence of small amounts of water (up to 6 wt%) has recently been proposed to be beneficial due to the decrease of viscosity and increase of conductivity that originate from increasing the ion mobility in the electrolyte [32e35]. Furthermore, by changing and controlling the water content, it is possible to tailor the morphologies and structures of the deposited coatings: pellet-like, nodular, or cauliflower-like [34,36]. On the contrary, the hygroscopicity of DESs might be disadvantageous as the increase of water content may cause a decrease of the electrochemical potential window [33,34].…”