Facile hydrothermal synthesis and electrochemical supercapacitor performance of hierarchical coral-like ZnCo₂O₄ nanowires

This paper reports a facile hydrothermal synthesis of hierarchical coral-like ZnCo₂O₄ nanostructures comprised of necklace type nanowires without the use surfactants. The hierarchical coral structure is composed of an interconnected necklace-type nanowire arrangement on the nanoscale, facilitating charge transportation. In addition, the coral-like ZnCo₂O₄ nanowires were mesoporous (29.36 m² g^− 1 and 18.96 nm), leading to large electrochemical active sites for the redox reaction and fast ion transport within the ZnCo₂O₄ nanowires. When used in electrochemical supercapacitors, the interconnected necklace type, coral-like ZnCo₂O₄ nanowires exhibited a significantly high specific capacity (694 F g^− 1 at a current density of 2 A g^− 1), high rate capability (264 F g^− 1 at 10 A g^− 1), and excellent cycling stability (capacitance retention of ∼ 85% even after 2000 cycles at a charge-discharge current density of 10 A g^− 1). These results suggest that hierarchical coral-like ZnCo₂O₄ nanowires are a promising electrode material for energy storage applications in high-performance pseudocapacitors.