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

G RAJESHKHANNA, EDIGA UMESHBABU and G RANGA RAO*

J. Chem. Sci. Vol. 129, No. 2, February 2017, pp. 157–166

Nanostructured Co3O4 on Ni-foam with diverse morphologies, high surface areas and porosity has been synthesized by employing different surfactants under hyrothermal conditions and subsequent calcination. The surfactants strongly influence the physicochemical properties of cobalt oxide samples. The cobalt oxide grown on Ni-foam without surfactant has flower-like morphology. However, the cobalt oxides synthesized by using cationic (CTAB) and non-ionic (Triton X-100) surfactants show flake-like morphology, but the spatial arrangements of flakes are found to be different in both the samples. The surfactant assisted cobalt oxides show average crystallite size of ~6.6-9.8 nm, surface area of 60-80 m2g-1 and suitable porosity (~3.8 nm pore diameter). These samples are found to perform better as charge storage electrode materials. The specific capacitance values of cationic and non-ionic surfactant assisted cobalt oxide materials, at current density of 1.0 A g-1, are 1820 and 806 F g-1, respectively, compared to 288 F g-1 of cobalt oxide prepared without surfactant. They also show excellent capacity retention 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 difference in the flakes arrangement.