Facile synthesis of flower-like α-Co(OH)2 nanostructures for electrochemical water splitting and pseudocapacitor applications

We describe a facile synthetic route to alpha-Co(OH)(2) nanostructures by heating a solution containing CoCl2, ethylene glycol, and oleylamine. Electron microscopy and X-ray diffraction analyses revealed that flower-like nanostructures of a-Co(OH)2 were formed by assembly of thin alpha-Co(OH)(2) nanosheets. These nanostructures exhibited high activity for electrochemical water splitting with a current density comparable to that obtained on the commercial Pt wire electrode. In addition, these flower-like alpha-Co(OH)(2) nanostructures showed specific capacitance as high as 440 F/g at a current density of 1 A/g and excellent stability without any noticeable loss in capacitance after 5000 cycles of the galvanostatic charge-discharge test. (C) 2016 Published by Elsevier B.V. on behalf of The Korean Society of Industrial and Engineering Chemistry.