A free template strategy for the synthesis of CoS2-reduced graphene oxide nanocomposite with enhanced electrode performance for supercapacitors

A nanocomposite of cobalt disulfide (CoS2) nanoparticles and chemically reduced graphene oxide (RGO) sheets was prepared through a facile solvothermal method without any template. The structural and morphological properties of CoS2-RGO nanocomposite were characterized through X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectra and thermo-gravimetric analysis. The electrochemical behavior of CoS2-RGO nanocomposite has been investigated using cyclic voltammograms, galvanostatic charge/discharge and electrochemical impedance spectroscopy in 6 M KOH electrolyte. A maximum specific capacitance of 331 F g−1 was obtained at a current rate of 0.5 A g−1 with a wide working potential window from −0.3 to 0.65 V.