Highly porous nanocomposite of NiMoS4 nanosheets and reduced graphene oxide for energy storage application

This study presents a high porous nanocomposite composed of reduced graphene oxide and NiMoS4 (RGO/NiMoS4) for supercapacitor electrode materials. The different morphologies of NiMoS4 growth on RGO sheets were obtained via a facile one-step microwave-assisted method. The obtained material comprised NiMoS4 nanoneedles of several nanometers in diameter, which are well attached to the surface of RGO nanosheets. The RGO/NiMoS4 nanocomposite had a mesoporous structure, high specific surface area, and high electric conductivity. These excellent characteristics yield a fast electron and ion transport, and a large number of electroactive sites. The RGO/NiMoS4 composite delivered a specific capacitance of 1273 F g(-1) at a current density of 1.0 A g(-1), high-rate capability of 71.3% retention from 1 to 6.5 A g(-1). Besides, an asymmetric supercapacitor device had a capacitance of 80 F g(-1) at a current density of 1.0 A g(-1) and an energy density of 82.5 Wh kg(-1) at a power density of 1000 W kg(-1) with an operating voltage of 1.6 V. Thus, the current RGO/NiMoS4 nanocomposite has a great potential for energy storage application.