▎ 摘　　要

This work demonstrates a novel and facile route for preparing graphene-based composites comprising of metal oxide nanoparticles and graphene A graphene nanosheet-bismuth oxide composite as electrode materials of supercapacitors was firstly synthesized by thermally treating the graphene-bismuth composite which was obtained through simultaneous solvothermal reduction of the colloidal dispersions of negatively charged graphene oxide sheets in N N-dimethyl formamide (DMF) solution of bismuth cations at 180 degrees C The morphology composition and microstructure of the composites together with pure graphite oxide and graphene were characterized using powder X-ray diffraction (XRD) FT-IR field emission scanning electron microscopy (FESEM) transmission electron microscope (TEM) thermogravimetry and differential thermogravimetry (TG-DTG) The electrochemical behaviors were measured by cyclic voltammogram (CV) galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) The specific capacitance of 255 F g(-1) (based on composite) is obtained at a specific current of 1 A g(-1) as compared with 71 F g(-1) for pure graphene The loaded-bismuth oxide achieves a specific capacitance as high as 757 Fg(-1) even at 10 A g(-1) In addition the graphene nanosheet-bismuth oxide composite electrode exhibits the excellent rate capability and well reversibility (C) 2010 Elsevier Ltd All rights reserved