A conceptual model for the structure of catalytically grown carbon nano-fibers
A conceptual model for the structure of catalytically grown carbon nano-fibers
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DOI：
10.1016/j.carbon.2005.02.031
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发表时间：
2005-08
期刊：
影响因子：
10.9
通讯作者：
Seong-Ho Yoon;Seongyop Lim;Seong-hwa Hong;Wenming Qiao;D. Whitehurst;I. Mochida;Bei An;K. Yokogawa-K.
中科院分区：
文献类型：
--
作者：
Seong-Ho Yoon;Seongyop Lim;Seong-hwa Hong;Wenming Qiao;D. Whitehurst;I. Mochida;Bei An;K. Yokogawa-K.
通过三种不同的方法制备了典型的片状、人字形和管状纳米碳纤维。通过SEM、TEM、STM和XRD等手段的综合观察，发现这些CNF具有共同的亚结构，我们称之为碳纳米棒（CNR）和碳纳米片（CNP）。CNR是8-10个石墨烯层的碳簇，具有约2.5nm的独特直径和15- 100 nm范围内的可变长度。CNP似乎是5-25个石墨烯堆叠的集合，可能通过几个CNR的缔合形成。刻面催化剂表面决定了最终纤维形式中CNR或CNP的特定有序排列，这导致产生片状、人字形或管状CNF。CNF的直径由CNR和CNP亚基（或一系列这些亚基）的长度和它们相对于纤维轴的缔合角限定。高温石墨化使CNR中碳六边形的端部（边缘）闭合，从而在CNF表面上形成同心分层的圆顶状帽。这样的子结构单元可以通过研磨分离。
Typical platelet-type, herringbone-type, and tubular-type carbon nano-fibers (CNF) were catalytically prepared through three distinctly different routes. By comprehensive observations using SEM, TEM, STM, and XRD, these CNFs were found to have common sub-structures, which we call carbon nano-rods (CNR) and carbon nano-plates (CNP). A CNR was a carbon cluster of 8–10 graphene layers with unique diameters of about 2.5nm and variable lengths in the range of 15–100nm. CNPs appeared to be sets of 5–25 graphene stacks, probably formed by association of several CNRs. The faceted catalyst surfaces determine the particular ordered arrangements of the CNRs or CNPs in the final fiber form that result in the production of platelet, herringbone, or tubular-type CNFs. The diameters of the CNFs were defined by the length of the CNR and CNP sub-units (or a series of these) and their angles of association relative to the fiber axis. Graphitization at high temperatures closed the ends (edges) of carbon hexagons in CNRs to form concentrically layered dome-like caps on the surface of CNFs. Such sub-structure units can be separated by grinding.