Cobalt oxide-decorated silicon carbide nano-tree array electrode for micro-supercapacitor application

A cobalt oxide (Co₃ O₄ )-decorated silicon carbide (SiC) nano-tree array (denoted as Co₃ O₄ /SiC NTA) electrode is synthesized, and it is investigated for the use in the micro-supercapacitor. Firstly, the well-standing SiC nanowires (NWs) are prepared by nickel (Ni)-catalyzed chemical vapor deposition (CVD) method, and then the thin layer of Co₃ O₄ and the hierarchical Co₃ O₄ nano-flower-clusters are, respectively fabricated on the side-walls and the top side of the SiC NWs via electrodeposition. The deposition of Co₃ O₄ on the SiC NWs benefits for the charge transfer at the electrode/aqueous electrolyte interface due to its extremely hydrophilic surface characteristic after Co₃ O₄ decoration. Furthermore, the Co₃ O₄ /SiC NTA electrode would possess a directional charge transport route along the nanowire length of SiC NWs owing to their well-standing architecture. By using the Co₃ O₄ /SiC NTA electrode for micro-supercapacitor, the areal capacitance obtained from cyclic voltammetry measurement reaches 845 mF cm⁻² at a 10 mV s⁻¹ scan rate. Finally, the capacitance durability is also evaluated by the cycling test of cyclic voltammetry at a high scan rate of 150 mV s⁻¹ for 2000 cycles.