High quality mirror finish fabrication of nickel electrodeposited using hydantoin from a mixture of choline chloride-ethylene glycol

Abstract

This work presents an efficient and facile electrodeposited nickel using an organic additive, namely hydantoin (HD) from choline chloride and ethylene glycol in 1:2 mol ratio. It has also been shown that a relatively high brightness of the nickel deposits. The electrochemical properties of the Ni electrolyte in the absence and presence of HD have been examined via cyclic voltammetry, chronocoulometry, and chronoamperometry. The inclusion of HD causes the deposition potential of nickel to shift to more negative overpotentials. From the UV-spectra, it has been confirmed that the speciation of the nickel solution remained unchanged even over a wide range of temperature and coordination environments around the nickel centre. The presence of HD participates in interfacial region, in other words, acts an effective species in the nucleation and growth mechanisms of Ni deposition. A mirror-like and shiny nickel layers free of crystal grain have been achieved in the presence of HD when hydantoin was utilized as an effective additive. From the x-ray diffraction (XRD), the impact of the HD additive on the crystal growth along the [200] and [220] orientations during bulk deposition has been proved.

Keywords

• Electroplating
• Nickel
• Deep eutectic solvents
• Additives
• Brightener
• Hydantoin