The role of the hydrocarbon source on the growth of carbon materials
The role of the hydrocarbon source on the growth of carbon materials
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DOI：
10.1016/j.carbon.2012.03.024
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发表时间：
2012-08
期刊：
影响因子：
10.9
通讯作者：
Ahmed Shaikjee;N. Coville
中科院分区：
文献类型：
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作者：
Ahmed Shaikjee;N. Coville
近年来，对碳纳米管的广泛研究导致了具有广泛形态的其他碳的合成和表征。目前的理解是，碳试剂在催化剂存在下分解，得到碳原子，然后碳原子联合收割机或挤出成碳纳米管、纤维（或球体）。这种机制并没有表明碳源的结构如何影响材料的生长，特别是在低温下。在本文中，我们表明，存在的证据表明，碳氢化合物（和其他碳试剂）的结构有能力影响碳的生长过程。这可以通过催化剂-反应物效应（和随后的催化剂重构）来实现，所述催化剂-反应物效应受到碳碎片的产生和气相中产生的自由基的影响，或者受到碳源与金属颗粒的直接反应的影响。提出了对当前Baker碳生长模型的修改，以显示金属-催化剂相互作用，该模型考虑了这一信息（特别是在低于500°C的温度下）。
In recent years extensive studies on carbon nanotubes has led to the synthesis and characterization of other carbons with a wide range of morphologies. Current understanding is that the carbon reagents decompose in the presence of a catalyst to give C atoms that then combine or extrude into carbon nanotubes, fibers (or spheres). This mechanism does not indicate how the structure of the carbon source can impact on a material’s growth, in particular at low temperatures. In this paper we show that evidence exists to indicate that the structure of hydrocarbons (and other carbon reagents) has the ability to influence the carbon growth process. This can be achieved by catalyst–reactant effects (and subsequent catalyst reconstruction) that are influenced by both the production of carbon fragments and radicals produced in the gas phase or by direct reaction of the carbon source with the metal particle. A modification of the current Baker carbon growth model, to show the metal–catalyst interactions, that takes this information into account (particularly at temperatures lower than 500°C) is proposed.