Rapid microwave-assisted synthesis of mesoporous NiMoO4 nanorod/reduced graphene oxide composites for high-performance supercapacitors

Abstract

Mesoporous NiMoO4 nanorods grown on the surface of reduced graphene oxide composites (NiMoO4-rGO) were synthesized via a simple, rapidly, and environment-friendly microwave-solvothermal method. The structure and morphology of the composites were characterized by X-ray diffraction, Raman spectra, scanning electron microscopy, and transmission electron microscopy. The NiMoO4-rGO composite exhibited high performance as an electrode material for supercapacitors. At a current density of 1Ag−1, the specific capacitance reached 1274Fg−1, which is higher than that of pure NiMoO4 (800Fg−1). NiMoO4-rGO can retain about 81.1% of its initial capacitance after 1000 charge/discharge cycles. Remarkably, NiMoO4-rGO composites can be applied in asymmetric supercapacitors with ultrahigh energy density of 30.3Whkg−1 at a power density of 187Wkg−1. The enhanced electrochemical performance of NiMoO4-rGO is mainly ascribed to the mesoporous-NiMoO4 nanorods with large specific surface area, as well as high coupling with conductive rGO.