Electrodeposition of Nickel in 1-Butyl-3-Methylimidazolium Tetrafluoroborate Ionic Liquids

The electrochemical behavior of Ni(II) in 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) ionic liquid was investigated by cyclic voltammetry at 353 K. The results show that the reaction of Ni(II) to Ni is irreversible and it proceeds via a one-step,two electrons transfer process. The diffusion coefficient of Ni(II) was estimated to be 4.4 x 10(-8) cm(2) s(-1) at 353 K. The electrodeposition of nickel was studied at different cathodic potentials (-0.70 to -0.85 V) and at different temperatures (333 to 363 K) in BMIMBF4 containing 0.20 mol L-1 Ni(BF4)(2). The deposits were characterized using scanning electron microscope (SEM), energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD). SEM images show that uniform, dense, and compact deposits were obtained at -0.70 V within a temperature range of 333 K to 343 K. EDS and XRD analysis confirm that high-purity metallic Ni deposits were obtained. (C) 2014 The Electrochemical Society. All rights reserved.