Porous Co3O4 nanowires derived from long Co(CO3)0.5(OH)·0.11H2O nanowires with improved supercapacitive properties
Abstract
Porous Co3O4 nanowires with large aspect ratio have been obtained by annealing long Co(CO3)0.5(OH)·0.11H2O precursor nanowires synthesized by a facile hydrothermal method. The results show that the amount of the additive (urea) has an important impact on the morphology of the as-synthesized cobalt-carbonate-hydroxide intermediate, where the uniformity and the overall structure can be controlled by changing the urea concentration. After the heat treatment, the as-obtained phase-pure Co3O4 nanowires with a well retained structure are applied as the electrode material for supercapacitors, and the sample exhibits excellent performance with a high specific capacitance of 240 F g−1 after 2000 charge/discharge cycles, corresponding to a retention of 98% of the initial capacitance.