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化学气相沉积法制备的纳米碳纤维(CNF)的形貌和结构取决于其制备工艺条件,包括催化剂的组成,制备温度和碳源的组成等。本文以纳米级的Fe3O4粉末为催化剂,CO为碳源,制备CNF,通过高分辨率透射电镜、N2吸附及热重分析考察制备工艺条件对CNF形貌和结构的影响。研究发现,生长温度越高,CNF的表面积和孔容逐渐减小,但仍属于板式纳米碳纤维。还原温度和H2浓度对CNF的形貌和微观结构影响较大,过低的还原温度会导致螺旋状CNF生成。
The morphology and structure of carbon nanofibers (CNF) prepared by chemical vapor deposition depend on the preparation conditions, including the composition of the catalyst, the preparation temperature and the composition of the carbon source. In this paper, nano-scale Fe3O4 powder as a catalyst, CO as a carbon source, CNF prepared by high-resolution transmission electron microscopy, N2 adsorption and thermal gravimetric analysis of preparation conditions on CNF morphology and structure. It was found that the higher the growth temperature, the smaller the surface area and pore volume of CNF, but still belongs to the plate-type carbon nanofibers. The reduction temperature and H2 concentration have a great influence on the morphology and microstructure of CNF. Too low a reduction temperature leads to the formation of spiral CNFs.