A Facile Two-Step Hydrothermal Synthesis of Co(OH)₂@NiCo₂O₄ Nanosheet Nanocomposites for Supercapacitor Electrodes

The composites of NiCo₂O₄ with unique structures were substantially investigated as promising electrodes. In this study, the unique structured nanosheets anchored on nickel foam (Ni foam) were prepared under the hydrothermal technique of NiCo₂O₄ and subsequent preparation of Co(OH)₂. The Co(OH)₂@NiCo₂O₄ nanosheet composite has demonstrated higher specific capacitances owing to its excellent specific surface region, enhanced rate properties, and outstanding electrical conductivities. Moreover, the electrochemical properties were analyzed in a three-electrode configuration to study the sample material. The as-designed Co(OH)₂@NiCo₂O₄ nanosheet achieves higher specific capacitances of 1308 F·g^-1 at 0.5 A·g^-1 and notable long cycles with 92.83% capacity retention over 6000 cycles. The Co(OH)₂@NiCo₂O₄ nanosheet electrode exhibits a long life span and high capacitances compared with the NiCo₂O₄ and Co(OH)₂ electrodes, respectively. These outstanding electrochemical properties are mainly because of their porous construction and the synergistic effects between NiCo₂O₄ and Co(OH)₂. Such unique Co(OH)₂@NiCo₂O₄ nanosheets not only display promising applications in renewable storage but also reiterate to scientists of the unlimited potential of high-performance materials.