Template-free solvothermal synthesis of NiS2 microspheres on graphene sheets for high-performance supercapacitors

Graphene/NiS2 composite was obtained through a template-free solvothermal reaction using graphene oxide (GO), Na2S2O3 center dot 5H(2)O and NiCl2 center dot 6H(2)O as reactants. Na2S2O3 center dot 5H(2)O plays an important role as the reducing agent for GO as well as the sulfur source for NiS2. Electrochemical behaviour of the graphene/NiS2 composite was studied through cyclic voltammetry and galvanostatic charge-discharge. As for the applications in supercapacitors, graphene/NiS2 composite shows a great value of 478.1 Fig at a current density of 0.5 A/g. Furthermore, the capacitance of graphene/NiS2 decreases only 10.7% of its initial value after 2000 cycles. (C) 2014 Elsevier B.V. All rights reserved,