Abstract: Single- and multi-layer graphene was fabricated from expanded graphite by liquid-phase exfoliation method in organic solvents. Its morphology and structure were characterized. The effects of organic solvent, time and reductant on the electrical properties of graphene platelets were studied by four-point probe characterization method, and the preparation conditions of graphene optimized. The results show that graphene platelets have high electrical conductivity by using acetone as the dispersant, which can achieve 219.09 S/cm. The graphene exhibits good electrochemical performance compared with the expanded graphite, its specific capacitance reaches 18.8 F/g. In PBS buffer solution of pH=7, a sensitive stripping peak at 0.1 V to Pb2+ ion occurs, and the detection limit is 0.05 mmol/L.

Key words: graphene, liquid-phase exfoliation, electrical conductivity, electrochemical performance

摘要： 在有机溶剂中超声剥离膨胀石墨制备单层和多层石墨烯，对其微观形貌和结构进行表征，采用四探针表征方法考察了溶剂、时间和还原剂对石墨烯电导率的影响，优化了制备工艺参数，分析了石墨烯的性能. 结果表明，以丙酮为分散剂时石墨烯导电率最高，可达219.09 S/cm，石墨烯具有良好的电化学性能，比电容达18.8 F/g，在pH=7的磷酸盐缓冲溶液中，在0.1 V电压下对Pb2+有灵敏的溶出峰，检出限位达0.05 mmol/L.

关键词: 石墨烯, 液相剥离, 导电率, 电化学性能