Preparation of Graphene/N-doped Carbon Nanohybrids and Their Application in Supercapacitors

Background: Nanocarbon hybrids have been a topic of interest in recent years because of their important role in energy storage and conversion device fabrication. Objective: To get low-cost graphene/N-doped carbon composites (G-NC) for supercapacitor applications. Method: G-NC samples were prepared with a two-step hydrothermal method and characterized with field emission scanning electron microscopy, 77K nitrogen adsorption, and X-ray photoelectron spectroscopy. The electrochemical performance of samples was investigated with cyclic voltammetry and charge-discharge measurements in threeelectrode configurations. Results: Samples showed a sheet-type morphology and nanoporous structure. The nanohybrids had a specific surface area of 350 m²g^-1, delivered maximum specific capacitance of 103 F g^-1 at 0.5A g^-1 in 6 M KOH with good cycle stability. Conclusion: Low-cost G-NC nanohybrids with good electrochemical performance are promising for supercapacitor applications.