Growth of carbon nanofilaments on coal foams
Growth of carbon nanofilaments on coal foams
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DOI：
10.1016/j.fuel.2008.07.026
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发表时间：
2009
期刊：
影响因子：
7.4
通讯作者：
M. Calvo;A. Arenillas;Roberto García;S. R. Moinelo
中科院分区：
文献类型：
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作者：
M. Calvo;A. Arenillas;Roberto García;S. R. Moinelo
通过催化化学气相沉积（CVD），使用乙烯/氢气混合物在Ni上的分解，在碳泡沫上生长纳米丝状碳。通过两阶段热处理从煤获得碳泡沫，其中第一阶段在前体煤的塑性区域内的温度下进行。泡沫的孔隙度和孔径主要受第一阶段反应器中达到的压力的影响。在CVD工艺中，700°C是获得良好的纳米丝产率的最佳温度。反应气体中的低乙烯/氢气比（1/4）产生几乎仅短且薄的碳纳米结构。较高比例的C2 H4（4/1，C2 H4/H2）得到更好的纳米丝产率，具有较长和较大直径（高达约0.5 μm）结构的良好比例。在所产生的碳形式中，透射电子显微镜显示鱼骨型纳米纤维占主导地位，还观察到一些竹状纳米管。
Nanofilamentous carbon was grown on a carbon foam by catalytic chemical vapour deposition (CVD) using the decomposition of ethylene/hydrogen mixtures over Ni. The carbon foam was obtained from a coal by a two-stage thermal process, with the first stage taking place at a temperature within the plastic region of the precursor coal. The extent of porosity and the pore size of the foam were mainly influenced by the pressure reached in the reactor during the first stage. In the CVD process, 700°C was the optimum temperature for obtaining good yields of nanofilaments. A low ethylene/hydrogen ratio (1/4) in the reactive gas gave rise to almost only short and thin carbon nanostructures. A higher proportion of C2H4 (4/1, C2H4/H2) gave better yields of nanofilaments, with good proportions of higher-length and higher-diameter (up to around 0.5 μm) structures. Among the carbon forms produced, transmission electron microscopy revealed the predominance of fishbone-type nanofibres, with some bamboo-like nanotubes being also observed.