Controllable synthesis of activated graphene and its application in supercapacitors
Controllable synthesis of activated graphene and its application in supercapacitors
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DOI：
10.1039/c4ta07203k
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发表时间：
2015-04
影响因子：
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通讯作者：
C. Zheng;Xufeng Zhou;Hanjie Cao;Guoshuai Wang;Zhaoping Liu
中科院分区：
文献类型：
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作者：
C. Zheng;Xufeng Zhou;Hanjie Cao;Guoshuai Wang;Zhaoping Liu
活化石墨烯被认为是超级电容器的理想电极材料。为了揭示活化石墨烯与其前驱体之间的关系并可控合成活化石墨烯，在活化石墨烯的合成过程中可控地调节前驱体（还原氧化石墨烯，RGO）的结晶度和附着的氧官能团等结构参数，并研究前驱体结构对活化石墨烯微观结构的影响。活化结果表明，RGO的结构明显影响活化石墨烯的多孔结构。具体而言，结晶度和氧官能团在活化石墨烯的孔隙率发展中起着重要作用。通过结合简化的Brodie方法和随后的后氧化工艺，成功制备了比表面积高达2406 m2 g−1和高孔体积的多孔活化石墨烯。当在以 EMIMBF4 离子液体作为电解质的两电极电池中测量时，所制备的活化石墨烯表现出良好的电容特性并提供高能量密度（55.7 W h kg−1）。结果表明，所获得的活化石墨烯可以被认为是超级电容器先进电极材料的候选材料。
Activated graphene has been considered as an ideal electrode material for supercapacitors. In order to reveal the relationship between activated graphene and its precursor and controllably synthesize activated graphene, the structural parameters of the precursor (reduced graphene oxide, RGO) such as crystallinity and attached oxygen-functional groups were controllably adjusted during the synthesis of activated graphene and the effects of the precursor structure on the microstructure of activated graphene were investigated. The activation results reveal that the structure of RGO obviously affects the porous structure of activated graphene. Specifically, the crystallinity and oxygen-functional groups play an important role in the porosity development of activated graphene. By combining the simplified Brodie method and the subsequent post-oxidation process, porous activated graphene with a specific surface area of as high as 2406 m2 g−1 and high pore volume has been successfully prepared. The as-prepared activated graphene exhibits good capacitive characteristics and delivers high energy density (55.7 W h kg−1) when measured in a two-electrode cell with the EMIMBF4 ionic liquid as the electrolyte. The results demonstrate that the obtained activated graphene can be considered as a candidate for advanced electrode materials for supercapacitors.