▎ 摘　　要

Self-assembed alpha-Fe2O3/reduced graphene oxide hydrogel(3DGH) composites were synthsized by facile hydrothermal method. The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy (Raman), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The alpha-Fe2O3 nanoparticles (about 100 nm in diameter) grow on the three-dimensional porous structure of reduced graphene oxide (RGO). In addition, the particle size of alpha-Fe2O3 can be controlled from 200 nm to 30 nm via adjusting the loading of Fe3+. This results show that the alpha-Fe2O3/3DGH composite with a Fe3+ loading amount of 40% and particle size of 100 nm has the maximum specific capacitance ( 750. 8 F/g at 1 A/g) and good cyclic performance (the specific capacitance retention is 81. 9% after 5000 cycles at 10 A/g), which is higher than that of pure alpha-Fe2O3 (251. F/g at 1 A/g and 43.8% after 5000 cycles).