Facile synthesis of hollow Fe2O3 nanotubes on nitrogen-doped graphene and their electrochemical performances

The design and optimization of electrode materials are critically important for the development of high-performance supercapacitors. Herein, hollow Fe2O3 nanotubes supported on nitrogen-doped graphene was fabricated via a facile hydrothermal process. The morphologies of the samples were characterized by scanning electron microscopy, X-ray photoelectron spectra, X-ray diffraction, and so on. The electrochemical performance was tested with a three-electrode system in the aqueous electrolyte of 2 M KOH. The hollow Fe2O3 nanotubes/nitrogen-doped graphene composite electrode demonstrated a high specific capacitance of 270 F/g (136 F/g for hollow Fe2O3 nanotubes/graphene electrode) at a current density of 1 A/g. Besides, over 89% of the original capacitance retention was maintained after 3000 cycles, indicating a good cycle stability of hollow Fe2O3 nanotubes/nitrogen-doped graphene electrode materials. In comparison with the hollow Fe2O3 nanotubes/graphene composite, the obviously improved electrochemical performance of hollow Fe2O3 nanotubes/nitrogen-doped graphene nanocomposite was possibly due to the synergistic effect, in which hollow Fe2O3 nanotubes provided a convenient channel for the ion transport and the nitrogen-doped graphene possessed the good electronic conductivity as well as more active sites than the pure graphene.