Electrochimica Acta, Vol.78, 92-97, 2012
Effect of scan rate on the morphology of potentiodynamically deposited beta-Co(OH)(2) and corresponding supercapacitive performance
Nanoflakes (average thickness 100 nm) of cobalt hydroxide (beta-Co(OH)(2)) were potentiodynamically deposited on stainless steel (SS) substrate. 0.1 M Co(NO3)(2) was used as starting material and the scan rate of the deposition was varied between 20 and 200 mV s(-1). These films were characterized for their structural and morphological study using X-ray diffraction and scanning electron microscope (SEM). The X-ray diffraction study revealed the formation of beta-Co(OH)(2) material with hexagonal crystal structure. Electrochemical properties of beta-Co(OH)(2) thin film electrode were studied using cyclic voltammetry and charge-discharge techniques. In present work, we studied effect of deposition scan rate on the morphology of the beta-Co(OH)(2). As the scan rate of the deposition increased, size of the nanoflakes became smaller and porous deposit was formed on the SS surface. Film deposited at high scan rate (200 mV s(-1)) showed maximum specific capacitance of 890 Fg(-1) in 1 M KOH electrolyte at the scan rate of 5 mVs(-1). (C) 2012 Elsevier Ltd. All rights reserved.