A facile one-pot microwave assisted hydrothermal synthesis of hierarchical cobalt oxide/reduced graphene oxide composite electrode for high-performance supercapacitors

Abstract

The composites composed of transition metal oxide and carbonaceous nanomaterials have been regarded as one of the promising electrode materials for high performance supercapacitors. How to develop effective hybridization of two components to deliver synergistic effect on electrochemical performance is a key question to be tackled. Herein, we successfully prepare three-dimensional hierarchical cobalt oxide (Co3O4)/reduced graphene oxide (rGO) composites via a facile, rapid and cost-effective one-pot microwave assisted hydrothermal process. The effects of rGO content on morphology, chemical and crystalline structure, electrode performance are systematically investigated. Interestingly, it is noticed that by changing the addition of graphene oxide (GO), the size of Co3O4 nanoparticles can be effectively controlled, which has a significant effect on the electrochemical properties of electrode materials. The as-prepared Co3O4/rGO with 23 wt% rGO exhibits an outstanding specific capacitance of 1031 F g−1 at 1 A g−1 and retains 78% of capacitance when current density increased to 10 A g−1, revealing that Co3O4/rGO composites prepared by this facile process can be an ideal candidate electrode for high performance supercapacitors.