【摘要】 以石墨为原料,采用改进的Hummers方法制备氧化石墨,在水中经超声分散得到氧化石墨烯水溶胶,经硼氢化钠还原得到石墨烯聚集物。采用扫描电镜、原子力显微镜、激光粒度分析仪、BET氮气吸附仪对样品的形态、粒度分布和比表面积进行了表征。采用恒流充放电和循环伏安法研究了样品的充放电性能。结果表明,氧化石墨在水溶液中可以剥离成单片层结构,石墨烯聚集物比表面积为358m2/g,在10mA恒流下充放电,比电容为138.6F/g,充放电容量效率为98%。以5～50mV/s扫描速率进行循环伏安测试,石墨烯电极表现出良好的双电层电容器性能。更多还原

【Abstract】 Graphite was oxidized with modified Hummers’s method and made into aqueous colloid with supersonic, in which the oxidized graphite were exfoliated into oxidized graphene layers. The graphene was gotten by reducing the graphene layers with sodium borohydride. The samples were characterized by scanning electron microscope, atomic force microscope, laser particle analyzer and BET surface analyzer, while the charge-discharge performance was investigated by constant current and cyclic voltammetry methods. The results show that the oxidized graphene can be dispersed in aqueous solution in single sheets. The surface area of graphene is 358 m2/g, and its charge capacitance at 10 mA is 138.6 F/g and the capacitance efficiency is 98%. The cyclic voltammetry test shows the graphene has good double layer electrical performance at scanning rates of 5-50 mV/s.更多还原