单壁碳纳米管的纯化工艺及其对材料结构的影响

Purification of Single Walled Carbon Nanotubes and its Effect on the Structure of Carbon Nanotubes

碳纳米管的纯化对于获得纯净的碳纳米管及其应用具有重要的意义.但是,传统的纯化方法主要是单纯的物理或化学方法.本研究采用了物理和化学方法相结合的方法来纯化单壁碳纳米管,主要过程包括酸化、离心、过滤等过程.通过扫描电子显微镜分析了纯化前后单壁碳纳米管的表面形态,在其表面的大部分杂质被除去,说明了此方法的纯化效果.用632.8nm波长的激发光测得了纯化前后单壁碳纳米管的拉曼光谱,纯化前后G模和D模拉曼谱的频移和半高宽发生了很大的变化.认为这是由于长时间的酸化改变了单壁碳纳米管的结构,甚至改变了单壁碳纳米管的类型.对D模的峰进行了归属指认,解释了此拉曼峰的起源.

The purification of carbon nanotubes is of great significance to obtain pure carbon nanotubes and their applications.However,the purification methods used are mainly pure physical or chemical methods.In this study,a combination of physical and chemical methods was used to purify single-walled carbon nanotubes.The main processes included acidification,centrifugation and filtration.Scanning electron microscopy(SEM)was used to analyze the surface morphology of single-walled carbon nanotubes before and after purification.The Raman spectra of single-walled CNTS were measured by excitation light of 632.8nm.The frequency shift and half-width of G-mode and D-mode Raman spectra changed greatly before and after purification.This is believed to be due to the long time of acidification changing the structure and even the type of single-walled CNTS.The attribution of D-mode peak is identified and the origin of the Raman peak is explained.