Microwave-assisted synthesis of iron oxide homogeneously dispersed on reduced graphene oxide for high-performance supercapacitor electrodes

Abstract

In this study, nanostructured composites with a unique morphology have been synthesized by dry microwave irradiation for application in supercapacitor electrodes. The microstructure of the hybrid material consisted of reduced graphene oxide (rGO) nanosheets homogeneously covered by nearly uniform-sized, faceted Fe3O4 nanoparticles. During the synthesis, graphite oxide was reduced, and FeCl3.6H2O was simultaneously decomposed into Fe3O4 nanoparticles. The surface morphology, the defects created in the rGO nanosheets by the addition of Fe3O4 nanoparticles, and the specific surface area of the as-synthesized materials have been studied. The electrode material, when tested in 1 M KOH electrolyte, delivered a specific capacitance of 771.3 F/g at a scan rate of 5 mV/s. Moreover, a high stability towards continuous charge/discharge cycling was observed, with ∼95.1 % capacitance retention after 5000 cycles. The synthesis approach adopted in this work could be applied to similar composite electrodes using layered conductive structures combined with metal oxides.