In situ grown nano-architectures of Co3O4 on Ni-foam for charge storage application

Nanostructured Co3O4 on Ni-foam has been synthesized with diverse morphologies, high surface area and porosity by employing different surfactants under hydrothermal conditions and subsequent calcination. The surfactants strongly influence the physicochemical properties of cobalt oxide samples. The cobalt oxide grown on Ni-foam without surfactant had flower-like morphology. However, cobalt oxides synthesized by using cationic (CTAB) and non-ionic (Triton X-100) surfactants showed flake-like morphology, but the spatial arrangement of flakes was found to be different in both the samples. The surfactant-assisted cobalt oxide showed average crystallite size of similar to 6.6-9.8 nm, surface area of 60-80 m(2)g(-1) and porosity (pore diameter similar to 3.8 nm). These samples were found to perform better as charge storage electrode materials. The specific capacitance values of cationic and non-ionic surfactant-assisted cobalt oxide materials, at a current density of 1.0 A g(-1), were 1820 and 806 F g(-1), respectively, compared to 288 F g(-1) of cobalt oxide prepared without surfactant. They also showed excellent capacity retention for over 3000 charge-discharge cycles at higher current densities. The difference in the capacitance values of cationic and non-ionic surfactant-assisted cobalt oxide is due to the difference in the flake arrangement.