Cobalt hydroxide hexagonal nanoplates anchored on functionalized carbon nanotubes (CNTs) for supercapacitor applications: one-pot electrochemical fabrication of high performance nanocomposite

Abstract

β-Co(OH)₂/CNTs nanocomposite was prepared through a facile electrodeposition method onto stainless steel grid, and its charge storage capacity in supercapacitor applications was studied. The co-deposition of cobalt hydroxide/CNTs was carried out, for the first time, from a CNTs–COOH dispersed aqueous electrolyte containing 0.005M CoCl₂. The simple deposition parameters were used, which included direct current mode (10 mA cm⁻²) at RT conditions. The characterization techniques of XRD, IR, FE-SEM, BET and TEM proved the deposition of crystalline β-Co(OH)₂ hexagonal nanoplates grown onto electrophoretically deposited CNTs on the cathode surface. BET test indicated that the high surface area of 144.8 m² g⁻¹ with micro-porous surface for the fabricated composite. The GCD tests showed excellent charge storage behavior with delivering specific capacitances as high as 1287 F g⁻¹ (0.5 A g⁻¹), 1124 F g⁻¹ (1 A g⁻¹), 956 F g⁻¹ (2 A g⁻¹), 834 F g⁻¹ (3 A g⁻¹), 712 F g⁻¹ (5 A g⁻¹) and 573 F g⁻¹ (10 A g⁻¹) and capacity decay of 10.6% during 5000 cycles.