铁纤维对气相沉积碳材料生长和形貌的影响

Effect of iron fibers on growth and morphology of carbon materials synthesized by chemical vapor deposition

化学气相沉积法制备的纳米碳材料(碳纳米管,碳纤维)的生长和形貌取决于其制备工艺条件,包括催化剂的组成,制备温度,碳源的种类等。以铁纤维为催化剂、甲烷为碳源气体、在不锈钢基底上制备碳材料后,通过扫描电子显微镜分析和考察铁纤维对产物的生长和形貌的影响。研究发现:在有铁纤维的位置,甲烷裂解生成的活性碳原子移动形成的碳层成为生长内核,生成直径为100～300nm的碳纳米管;在没有铁纤维的位置,含有硅元素的小质点成为形核点,生成直径为1～2μm的碳纤维。

The growth and morphology of carbon materials （carbon nanotubes, carbon fibers） synthesized by chemical vapor deposition depend upon the preparation conditions including the catalyst composition and structure, synthesis temperature, composition of carbon feedstock, etc. Carbon materials have been synthesized on stainless steel substrate deposited with iron fibers using chemical vapor deposition method, using CH4 as reaction gases. The growth and structure of carbon materials were investigated by scanning electron microscopy. The results show that iron fibers greatly affect the growth and structure of carbon materials. At the position where the iron fibers existed, the carbon layers are behaved as the inner cores of vapor-grown carbon nanotubes, which are formed by the migration of active carbon atoms decomposed by CHa, carbon nanotubes whose diameter are 100-300 nm can be obtained; but where without iron fibers, the material points containing silicon are behaved as nucleating centre, carbon fibers whose diameter are 1 -2 μm can be obtained.