Hydrothermal synthesis of Ni3S2/graphene electrode and its application in a supercapacitor

In this work, we demonstrate a simple hydrothermal synthesis of nickel sulfide/graphene nanosheets (Ni3S2/GNS) and use the nanocomposite as an electrode for a supercapacitor. X-ray diffraction, scanning electron microscopy and Raman spectroscopy were used to investigate the morphologies and microstructures of the resulting electrode materials. Detailed electrochemical characterization shows that the Ni3S2/GNS electrode exhibits high specific capacitance of about 1420 F g(-1) at a current density of 2 A g(-1). At a current density of 6 A g(-1), the specific capacitance of the Ni3S2/GNS electrode remains fairly constant at the initial value over 2000 cycles, obviously illustrating a relatively high cycling stability. The outstanding electrochemical properties of the Ni3S2/GNS nanocomposite suggest that it has great potential for practical applications in high-performance supercapacitors.