Preparation of graphene nanosheets from microcrystalline graphite by low-temperature exfoliated method and their supercapacitive behavior

Microcrystalline graphite, a kind of cheap and infrequently used graphite material, used for the rapid synthesis of graphene nanosheets (MGS) by thermal reduction-exfoliation of graphite oxide at low temperature (as low as 100 A degrees C) is reported. The results indicate that the microcrystalline graphite could be oxidized completely. X-ray diffraction patterns show that the obtained MGS exhibit an amorphous structure. Scanning electron microscopy images show that the MGS samples possess nanoporous structure. The results of N-2 adsorption-desorption analysis indicate that the MGS samples possess high Brunauer Emmett Teller surface areas (the highest is 374 m(2) g(-1)). The results of electrochemical tests show that the MGS exfoliated at 400 A degrees C (MGS-400) has better supercapacitive performance than that of MGS exfoliated at 100 A degrees C. The specific capacitance value of MGS-400 is about 212 F g(-1) at 5 mV s(-1). And also the MGS samples have good rate performance and cycle stability.