Facile synthesis of CuCo2S4 nanoparticles as a faradaic electrode for high performance supercapacitor applications

In this paper, we report the synthesis of spinel CuCo2S4 nanoparticles (NPs) via a one-step hydrothermal method using two kinds of sulfur precursor's thioacetamide-TAA and thiourea-TU separately. The X-ray powder diffraction (XRD) analysis of both samples revealed a cubic phase of spinel CuCo2S4 crystal structure with Fd3m space group. The spherical (19-20 nm) and hexagonal (17-19 nm) shaped NPs were observed by transmission electron microscope (TEM) images. N-2 adsorption-desorption results showed the high surface area of TAA-CuCo2S4 (91.03 m(2) g(-1)) than TU-CuCo2S4 (59.82 m(2) g(-1)). XPS spectra exhibited the coexistence of Cu2+ and Cu3+ valence states of spinel cubic CuCo2S4. Electrochemical measurements showed that the TAA based CuCo2S4/Ni foam electrode has high specific capacity (1885 C g(-1)/523 mA h g(-1) at a current density of 2 A g(-1) about 5.4 times higher than thiourea based electrodes), ultrahigh capacity retention of 98% after 6000 GCD cycles at high current density of 10 A g(-1) and excellent energy density of 41.89 provided with a power density of 318.31 W kg(-1). These results suggest that TAA assisted electrode material is suitable for improving electrochemical performance of supercapacitors.