Large-area synthesis of carbon nanofibres at room temperature
Large-area synthesis of carbon nanofibres at room temperature
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DOI：
10.1038/nmat755
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发表时间：
2002-11-01
期刊：
影响因子：
41.2
通讯作者：
Silva, SRP
中科院分区：
文献类型：
--
作者：
Boskovic, BO;Stolojan, V;Silva, SRP
碳纳米管首先由Iijima发现，其生产需要元素碳源和特定于源类型和生长环境的能量转移。迄今为止开发的方法包括电弧放电、使用激光的汽化、热解和碳氢化合物的化学气相沉积。在这里，我们展示了在室温下从射频等离子体增强化学气相沉积中生长碳纳米纤维，这是通过用Ni催化剂上甲烷的等离子体分解替代生长的热能要求而实现的。电子显微镜分析提供了证据的“尖端”生长模型，与Ni催化剂颗粒连接到纳米纤维的尖端。能量过滤成像显示Ni催化剂具有富含碳的表面层，这与作为碳纳米纤维的成核位点的共晶Ni-C液滴的形成一致，使得碳在整个表面上扩散。催化剂颗粒在低温下的变形减少导致碳纳米纤维在大面积上更均匀地生长。较低的生长温度允许去除与催化生长相关的二氧化硅阻挡层，并且应该允许纳米纤维在相对大面积的温度敏感基底（例如塑料、有机物甚至纸）上原位生长。
Carbon nanotubes, first identified by Iijima, require for their production a source of elemental carbon and a transfer of energy that is specific to the type of source and the growth environment. Methods developed so far involve arc discharge, and vaporization using laser,, pyrolysis,and chemical vapour deposition of hydrocarbons. Here, we show growth of carbon nanofibres from radio-frequency plasma-enhanced chemical vapour deposition at room temperature, which was made possible by substituting the thermal energy requirements for the growth with plasma decomposition of methane on the Ni catalyst. Electron microscopy analysis provides evidence for a 'tip' growth model, with the Ni catalyst particle attached to the tip of the nanofibre. Energy-filtered imaging shows the Ni catalyst has a surface layer rich in carbon, consistent with the formation of a eutectic Ni–C droplet as a nucleation site for the carbon nanofibres, so that the carbon diffuses across the surface. The reduced distortion of the catalyst particles at low temperatures leads to a more uniform growth of the carbon nanofibres over large areas. The lower growth temperature allows for the removal of the silicon dioxide barrier layer associated with catalytic growth, and should allowin situgrowth of nanofibres on relatively large areas of temperature-sensitive substrates, such as plastics, organics and even paper.