Microwave-assisted thin reduced graphene oxide-cobalt oxide nanoparticles as hybrids for electrode materials in supercapacitor

•Microwave synthesis method is very fast, single-step and cost-effective.•Co3O4/CoO nanoparticles are covered by rGO nanosheets via microwave irradiation.•Hybrid materials show good specific capacitance with high cycling stability.•Reduction/exfoliation of graphite oxide provide high temperature.•Microwave reduction, exfoliation and metal oxide covering occurs at same time.