A facile hydrothermal synthesis of graphene/RuO2/Co3O4 nanocomposites with high pseudocapacity

Graphene/RuO2/Co3O4 (GRC) nanocomposites, synthesized using a one-step facile and efficient hydrothermal method, have been investigated as advanced electrodes for supercapacitors. The physical properties of the GRC nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy and X-ray diffraction. Furthermore, the electrochemical properties were tested using an electrochemical workstation with a three-electrode system. Graphene acted as an excellent conductive substrate to provide an ultra-high specific surface area for contact with the electrolyte. The metal oxide particles (diameter <5 nm) anchored to graphene discretely. The highly dispersed RuO2 and Co3O4 particles contributed to the outstanding electrochemical performance and could significantly promote the capacitance compared to any one component alone. The GRC nanocomposites exhibited a high capacitance of 715 F g(-1) at a current of 1 A g(-1) and a wide electrochemical window of 1.4 V. The novel combination of these three materials can efficiently enhance the electrochemical performance and can be considered as a potential way to design and develop advanced supercapacitor electrode materials.