Graphene Research Center, KAIST Institute for the NanoCentury, Division of Ocean Systems Engineering, School of Mechanical, Aerospace and Systems Engineering, Korea Advanced Institute of Science and Technology, 335 Gwahak-ro, Yuseong-gu, Daejeon 305-701, Republic of Korea.
ACS Nano. 2012 Dec 21;6(12):10562-70. doi: 10.1021/nn3046133. Epub 2012 Nov 6.
The development of three-dimensional carbon-based nanostructures is the next step forward for boosting industrial applications of carbon nanomaterials such as graphenes and carbon nanotubes. Some defects, which have been considered as detrimental factors for maintaining exceptional materials properties of two-dimensional graphene, can be actively used to synthesize three-dimensional graphene-based carbon nanostructures. Here we describe a fast and heretofore unreported defect-engineered method to synthesize three-dimensional carbon nanohybrid structures with strong bonding between graphene nanoplatelets and carbon nanotubes using simple microwave irradiation and an ionic liquid. Our one-pot method utilizes defect-engineered sequential processes: microwave-based defect generation on graphene nanoplatelets, anchoring of palladium nanoparticles on these defects, and subsequent growth of carbon nanotubes by use of an ionic liquid. The unique three-dimensional nanostructures showed an ultrahigh redox capacitance due to high porosity, a high surface-to-volume ratio from the spacer role of vertically standing one-dimensional carbon nanotubes on graphene sheets, and capacitance-like redox response of the palladium nanoparticles. The proposed defect-engineered method could lead to novel routes to synthesizing three-dimensional graphene-based nanostructures with exceptionally high performance in energy storage systems.
三维碳基纳米结构的发展是推动石墨烯和碳纳米管等碳纳米材料工业应用的下一步。一些被认为对二维石墨烯保持特殊材料性能有害的缺陷，可以被积极用于合成三维石墨烯基碳纳米结构。在这里，我们描述了一种快速的、迄今为止尚未报道的缺陷工程方法，该方法使用简单的微波辐照和离子液体合成具有石墨烯纳米片和碳纳米管之间强键合的三维碳纳米杂化结构。我们的一锅法利用缺陷工程化的顺序过程：在石墨烯纳米片上进行基于微波的缺陷生成，在这些缺陷上锚定钯纳米粒子，然后使用离子液体生长碳纳米管。由于高孔隙率、垂直排列的一维碳纳米管在石墨烯片上的间隔作用产生的高表面积与体积比，以及钯纳米粒子的电容式氧化还原响应，这种独特的三维纳米结构表现出超高的氧化还原电容。所提出的缺陷工程方法可能会为在储能系统中合成具有异常高性能的三维石墨烯基纳米结构开辟新途径。
