Synthesis of graphene-like nanosheets and their hydrogen adsorption capacity
Synthesis of graphene-like nanosheets and their hydrogen adsorption capacity
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DOI：
10.1016/j.carbon.2009.10.003
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发表时间：
2010-03-01
期刊：
影响因子：
10.9
通讯作者：
Ruoff, Rod
中科院分区：
文献类型：
--
作者：
Srinivas, G.;Zhu, Yanwu;Ruoff, Rod
通过还原剥离氧化石墨的胶体悬浮液合成了类石墨烯纳米片。利用扫描电子显微镜、透射电子显微镜、X射线衍射和拉曼光谱研究了石墨烯粉末样品的形貌和结构。发现石墨烯片处于高度团聚状态，具有许多皱纹。在 77 K 下通过氮气吸附测量，样品的 BET 表面积为 640 m(2)/g。在 77-298 K 的温度范围和高达 10 bar 的压力下测量氢气吸附-解吸等温线。这使得在 77 K 和 298 K 时氢吸附容量分别约为 1.2 wt.% 和 0.1 wt.%。等量吸附热在 5.9-4 kJ/mol 范围内，表明氢与石墨烯片表面之间存在良好的相互作用。估计室温 H(2) 在 100 bar 下的吸收能力为 0.72 wt.%，我们的样品的等量吸附热与高表面积活性炭相当，但明显优于最近报道的石墨烯和一系列其他碳和纳米多孔材料的值；单壁和多壁碳纳米管、纳米纤维、石墨和沸石。 (C) 2009 Elsevier Ltd. 保留所有权利。
Graphene-like nanosheets have been synthesized by the reduction of a colloidal suspension of exfoliated graphite oxide. The morphology and structure of the graphene powder sample was studied using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy. The graphene sheets are found to be in a highly agglomerated state, with many wrinkles. The sample has a BET surface area of 640 m(2)/g as measured by nitrogen adsorption at 77 K. Hydrogen adsorption-desorption isotherms were measured in the temperature range 77-298 K and at pressures of up to 10 bar. This gives hydrogen adsorption capacities of about 1.2 wt.% and 0.1 wt.% at 77 K and 298 K, respectively. The isosteric heat of adsorption is in the range of 5.9-4 kJ/mol, indicating a favourable interaction between hydrogen and surface of the graphene sheets. The estimated room temperature H(2) uptake capacity of 0.72 wt.% at 100 bar and the isosteric heat of adsorption of our sample are comparable to those of high surface area activated carbons, however significantly better than the recently reported values for graphene and a range of other carbon and nanoporous materials; single and multi walled carbon nano-tubes, nanofibers, graphites and zeolites. (C) 2009 Elsevier Ltd. All rights reserved.