Facile synthesis of ultrathin and perpendicular NiMn2O4 nanosheets on reduced graphene oxide as advanced electrodes for supercapacitors

Ultrathin nickel manganese oxide nanosheets grown vertically on reduced graphene oxide (NiMn2O4 NSs@rGO) were successfully fabricated through a facile co-precipitation and thermal treatment process. Such a unique nanostructure can not only facilitate electron transfer and electrolyte penetration but also withstand the structural damage of the active materials in electrochemical reactions. The resulting product NiMn2O4 NSs@rGO was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) analysis. When evaluated for its potential as an electrode material in supercapacitors, the as-synthesized NiMn2O4 NSs@rGO nanocomposite exhibits enhanced energy storage performance with high specific capacitance (1243 F g(-1) at 3 A g(-1)) and prominent cycle life (80.8% capacitance retention after 5000 cycles). These results indicate that the ultrathin and perpendicular NiMn2O4 nanosheets with rGO substrates obtained from this green and facile route hold great prospects in high performance supercapacitor applications.