One-step strategy to a three-dimensional NiS-reduced graphene oxide hybrid nanostructure for high performance supercapacitors†
Metal sulfides are an emerging class of high-performance electrode materials for electrochemical energy storage devices. Here, a facile hydrothermal method is reported to assemble three-dimensional (3D) NiS-reduced graphene oxide (rGO) hybrid aerogels with strong coupling between the two compounds. It is intriguing to note that NiS nanoparticles are well anchored on the 3D porous and conductive scaffold constructed from wrinkled rGO nanosheets. When evaluated as binder-free electrode materials for supercapacitors, impressive electrochemical performances are presented. Specifically, the 3D NiS–rGO aerogel nanocomposite exhibits a high capacitance of 852 F g−1, 526 F g−1 based on the whole electrode mass (mNiS : mGO = 45 mg/50 mg) at a current density of 2 A g−1 and 15 A g−1, respectively. These satisfactory electrochemical behaviors, attributed to the introduction of reduced graphene oxide, suggest the great promise of fabricating graphene-supported hybrid electrode materials for high-performance energy applications.