γ-Ray-induced synthesis and electrochemical properties of a mesoporous layer-structured α-Co(OH)2 for supercapacitor applications

alpha-Cobalt hydroxide is synthesized through a novel radiation-induced route using a cobalt nitrate hexahydrate isopropanol solution by irradiating Co-60 gamma-rays. The as-prepared product shows a layer-structured mesoporous morphology with an average size of 250 nm. Crystalline property analysis exhibits the presence alpha-Co(OH)(2) as a predominant phase with a tiny amount of secondary phases of beta-Co(OH)(2) and CoO. X-ray photoelectron spectroscopy discloses the existence of Co as Co(OH)(2) and CoO with a stoichiometric ratio of 76.7:23.3. In addition, the supercapacitive properties of the product are investigated using cyclic voltammetry and impedance spectroscopy in 1M KOH aqueous solution, showing a maximum capacitance value of 246.7 F g (1) at a scan rate of 5 mV s (1). (C) 2011 Elsevier B. V. All rights reserved.