Electrodeposition of Nickel from Reverse Micellar Solutions of Cetyltrimethylammonium Bromide

Abstract

Electrochemical behavior of nickel chloride was investigated in aqueous and reverse micellar solutions of a cationic surfactant, cetyltrimethylammonium bromide (CTAB) on glassy carbon (GC) and copper electrodes by cyclic voltammetric measurements. The electrochemical reduction of nickel ion to metallic nickel has been found to occur with ease on a copper electrode in aqueous solution. Electrodeposition of nickel on a copper substrate was therefore performed from reverse micellar solutions of CTAB/1-butanol/water with different water content using coulometric method at a fixed potential below the reduction potential. Morphology and microstructure of the deposits were examined by scanning electron microscopy; while elemental characterization was carried out by energy dispersive X-ray spectroscopic method and X-ray diffraction technique. The variation in the composition of the reverse micellar solutions brings about changes in the size and distribution of reverse micelles as revealed by dynamic light scattering measurements and consequently influences the morphology of electrodeposited nickel. The mechanism of electrodepostion of nickel from reverse micellar solutions has been elucidated and the organized media have, for the first time, been established as a suitable one for electrodeposition of nickel with tunable microstructure and morphology through systematic variation of the composition of the reverse micellar solutions.