Options
Tuning of capacitance behavior of NiO using anionic, cationic, and nonionic surfactants by hydrothermal synthesis
Date Issued
25-03-2010
Author(s)
Justin, P.
Meher, Sumanta Kumar
Rao, G. Ranga
Abstract
In this work, NiO powders with a spherical morphology were synthesized by a simple hydrothermal technique using organic surfactants as templates and urea as the hydrolysis controlling agent. The effect of cationic (cetyl trimethyl ammonium bromide), anionic (sodium dodecyl sulfate), and nonionic (Triton X-100) surfactants for tuning the surface area, pore size, pore volume, and electrochemical properties of NiO powders was investigated. The NiO powders were characterized by X-ray diffraction, scanning electron microscopy, the Brunauer-Emmett-Teller method, cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy. We observed that the charge-storage mechanism in our NiO-based electrodes is significantly Faradic in nature rather than capacitive type. The ionic nature of the surfactant used in the preparation of NiO powders shows a considerable effect on their capacitance behavior. The specific capacitance values were found to increase in the order of NiO-T (144 F g-1) NiO-C (239 F g-1) < NiO-S (411 F g-1) at a current density of 200 mA g-1 in 2 M KOH aqueous electrolyte solution. The NiO-S sample exhibits the highest surface redox reactivity and shows the specific capacitance of 235 F g-1 over 100 cycles at a current density of 500 mA g-1 in a life cycle test. © 2010 American Chemical Society.
Volume
114