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

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 Fe 3 O 4 nanoparticles. During the synthesis, graphite oxide was reduced, and FeCl 3 .6H 2 O was simultaneously decomposed into Fe 3 O 4 nanoparticles. The surface morphology, the defects created in the rGO nanosheets by the addition of Fe 3 O 4 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. • Composites with a unique morphology have been synthesized by microwave irradiation. • Composite consists of reduced graphene oxide fully covered by Fe 3 O 4 nanoparticles. • Composite material used as electrode in supercapacitor shows improved performance. • Composite materials delivered high value of specific capacitance (about 771.3 F/g). • Nearly 95.1 % capacitance retention was achieved after 5000 charge/discharge cycles.