Cutting and Unzipping Multiwalled Carbon Nanotubes into Curved Graphene Nanosheets and Their Enhanced Supercapacitor Performance
Cutting and Unzipping Multiwalled Carbon Nanotubes into Curved Graphene Nanosheets and Their Enhanced Supercapacitor Performance
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将多壁碳纳米管切割并解压成弯曲石墨烯纳米片及其增强的超级电容器性能
DOI：
10.1021/am302000z
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发表时间：
2012-12-01
影响因子：
9.5
通讯作者：
Wang, Xuefeng
中科院分区：
文献类型：
--
作者：
Wang, Huanwen;Wang, Yalan;Wang, Xuefeng
我们报告了一个显着的多壁碳纳米管（MWCNTs）弯曲的石墨烯纳米片（CGN）的Hummers方法的转变。通过这个简单的过程，可以分别在横向和纵向方向上切割和拉开多壁碳纳米管。所制备的CGN具有独特的一维纳米管和二维石墨烯的混合结构。当用作超级电容器电极时，这种特定的结构与改进的有效表面积一起提供了高的比电容和在充电-放电过程期间良好的循环稳定性。电化学测量表明，CGN表现出更高的电容性能比原始的MWCNTs在三种不同类型的水性电解质，1 M KOH，1 M H2SO 4，和1 M Na 2SO 4。在0.3 A g（-1）的电流密度下，CGN材料的比电容高达256 F g（-1）。改进的电容可归因于对电解质离子的高可及性、扩展的缺陷密度和增加的有效表面积。同时，这种从低成本MWCNTs高产率生产石墨烯对于石墨烯的规模化合成和工业应用是重要的。此外，这种新型的CGN纳米结构也有希望应用于许多领域，如纳米电子学，传感器，纳米复合材料，电池和气体储存。
We report a remarkable transformation of multiwalled carbon nanotubes (MWCNTs) to curved graphene nanosheets (CGN) by the Hummers method. Through this simple process, MWCNTs can be cut and unzipped in the transverse and longitudinal directions, respectively. The as-obtained CGN possess the unique hybrid structure of 1D nanotube and 2D graphene. Such a particular structure together with the improved effective surface area affords high specific capacitance and good cycling stability during the charge-discharge process when used as super-capacitor electrodes. The electrochemical measurements show that CGN exhibit higher capacitive properties than pristine MWCNTs in three different types of aqueous electrolytes, 1 M KOH, 1 M H2SO4, and 1 M Na2SO4. A specific capacitance of as high as 256 F g(-1) at a current density of 0.3 A g(-1) is achieved over the CGN material. The improved capacitance may be attributed to high accessibility to electrolyte ions, extended defect density, and increased effective surface area. Meanwhile, this high-yield production of graphene from low cost MWCNTs is important for the scalable synthesis and industrial application of graphene. Furthermore, this novel CGN nanostructure could also be promisingly applied in many fields such as nanoelectronics, sensors, nanocomposites, batteries, and gas storage.