In situ growth of hexagonal-shaped a-Fe_2O_3 nanostructures over few layered graphene by hydrothermal method and their electrochemical performance

摘要

Abstract A simple in situ hydrothermal method was developed to anchor α-Fe~(2)O~(3)(hematite) on reduced graphene oxide (rGO) surfaces. The impact of functional groups of graphene oxide (GO) and the coordination between metal and carbonyl group was studied by Fourier transform infrared spectroscopy. The crystallographic structure of the hybrid composite material was examined by X-ray diffraction (XRD) analysis. The microscopic images indicate the decoration of Fe~(2)O~(3)nanostructures with an average size of 35–40 nm were encapsulated in rGO sheets. The XPS and Raman spectroscopy results further corroborate that α-Fe~(2)O~(3)is successfully formed on the rGO matrix, which is in good accordance with XRD results. The presence of α-Fe~(2)O~(3)nanostructures between the graphene layers avoids the restacking efficiently and increases the surface area accessibility. α-Fe~(2)O~(3)/rGO nanocomposites modified electrode exhibits 894 F g_(−1)specific capacitance at a current density of 0.5 A g_(−1)in 1 M H~(2)SO~(4)electrolyte. Furthermore, these trouble-free and cost effectively-prepared hierarchical materials showed high rate capability and excellent cycle stability.