Controllable synthesis of triangle taper-like cobalt hydroxide and cobalt oxide

Triangle taper-like beta-Co(OH)(2) and mesoporous Co3O4 microcrystals are synthesized by a simple solid-state crystal reconstruction approach. Ostwald ripening and successive dissolve-reconstruction processes were used to explain the formation mechanism. The electrochemical properties of the beta-Co(OH)(2) and mesoporous Co3O4 electrodes were investigated by cyclic voltammetry measurements. The specific capacitances are 137.6, 124.8, 108.8 and 98.0 F g(-1) at scan rates of 5, 10, 20 and 50 mV s(-1) for beta-Co(OH)(2); 91.5, 97.4, 90.7 and 70.9 F g(-1) for Co3O4 sample at scan rates of 5, 10, 20 and 50 mV s(-1). The magnetic properties also have been investigated at room temperature.