The effect of supporting electrolyte concentrations on the growth of nickel nanostructures

Abstract

Nickel nanostructures (Ni NSs) were grown on poly N-methyl pyrrole (PMPy) surface via facile electrochemical deposition method. Morphology and crystalline properties of the fabricated Ni NSs were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), and cyclic voltammetry (CV). The size-strain plot model was employed to determine the average crystallite sizes of Ni NSs prepared at 0.001, 0.01 and 0.1 M of KCl concentrations, respectively. Results indicated that Ni NSs morphologies were influenced by the concentration of KCl electrolyte in which utilized as supporting electrolyte. The average crystallite size decreased as the KCl electrolyte concentration increased. An irregular structure consisting of microspheres with an average size of 2 µm, nanodendritic structure with an average thickness of 120 nm and a large-scale uniform nanowall structure with an average thickness of 70 nm were formed in the presence of 0.001, 0.01 and 0.1 M KCl concentrations, respectively. The electrochemical behavior of Ni NSs characterized by cyclic voltammetry (CV) in 1 M solution of KOH revealed an improvement in the redox reaction of the Ni nano wall (Ni NW) compared to other Ni NSs electrodes, thus making Ni NW a good candidate for future utilization in electrode materials of fuel cells.