碳纳米团簇向碳纳米纤维相转变机理研究

Phase transformation mechanism of carbon cluster to fiber

为了能够快速且大面积生长碳纳米纤维,研究碳纳米纤维的形成、转变及在各种物理、化学环境下的反应机理,应用等离子化学气相沉积(PECVD)方法,以CH4为反应气体,FeCl2为催化剂在玻璃衬底上生长碳纳米薄膜.应用扫描电镜(SEM)观察了碳纳米纤维薄膜的表面形貌,拉曼(Raman)光谱分析了碳纳米纤维的结构组成.结果表明,无催化剂时薄膜主要由纳米团簇构成,而催化作用下薄膜呈纤维状生长,纳米纤维为典型的碳纳米管石墨特征峰.在温度,气压,催化剂等反应条件中,FeCl2催化剂对碳纳米薄膜的取向生长起决定性作用,通过调节催化剂的浓度与分布,可有效改变碳纳米纤维的密度与分布.

To rapidly grow carbon nanometer fiber in large area, the formation, transformation and the physical and chemical reactive mechanism of carbon nanometer fiber were investigated. Carbon nanofiber films were deposited on glass substrates by the method of plasma-enhanced chemical vapor deposition （PECVD） using CH4 as reactive gas and FeCl2 as catalyst. The surface morphology of the carbon nanometer films was observed by scanning electron microscopy （SEM） , and the structure composition was analyzed by Raman spectra. The results show that without catalyst the film consists of carbon nanometer clusters, but it presents fiber-like growth when the substrate is coated with catalyst. The fibers are characteristics of the structure of graphite. Among the growth conditions of temperature, pressure and catalyst, catalyst plays a key role in the orientation growth of carbon fiber. Adjusting the concentration and distribution of the catalysts can effectively change the density and distribution of the fibers