变径反应器浮游催化裂解法制备双壁碳纳米管  

Synthesis of double-walled carbon nanotubes by floating chemical vapor deposition method in a reactor with varied diameter

作　　者：张磊[1] 肖南[1] 于畅[1] 赵宗彬[1] 邱介山[1,2] 

机构地区：[1]大连理工大学精细化工国家重点实验室炭素材料研究室,辽宁大连116012 [2]大连理工大学辽宁省微纳米技术及系统重点实验室,辽宁大连116023

出　　处：《中国科技论文在线》2010年第12期972-978,共7页

基　　金：国家自然科学基金资助项目(20725619;20836002;50772017)

摘　　要：使用改进的变径管式反应器,以二茂铁为催化剂前驱体,二甲苯为碳源,硫磺为助剂,采用浮游催化裂解法,制备得到高质量的丝状双壁碳纳米管。系统优化了变径反应器制备双壁碳纳米管的工艺条件,并对不同参数条件下的产物进行了扫描电子显微镜、透射电子显微镜、拉曼光谱和热重表征。结果表明:由2个不同管径石英管无缝连接组成的变径反应器,可有效调节反应器内不同位置的气流流速,控制浮游催化剂纳米颗粒的粒径大小和气体碳源的停留时间,从而调控催化剂的催化活性以及提高碳源利用效率,促进双壁碳纳米管的生成;助剂硫磺的添加量以及气流流量对产物的种类、形貌和纯度有重要的影响。分析探讨了产物在变径反应器内区域选择性生长的原因以及变径结构对产物生长过程的影响。变径结构反应器技术为双壁碳纳米管的大规模连续化生产设备的研制提供了一种新的思路。Double-walled carbon nanotubes （DWCNTs） have been synthesized by a floating catalytic chemical vapor deposition method with ferrocene as catalyst precursor,xylene as carbon sources and sulfur as additive,which was conducted in a reactor with varied diameter. The as-grown products were characterized by scanning electron microscope （SEM）,transmission electron microscope （TEM）,Raman spectrometer,thermo gravimetry-differential thermal analysis （TGA-DTA）. The results showed that the carrier gas velocity in different parts of the reactor can be adjusted effectively,by making use of a diameter-varied reactor made of two quartz tubes with different diameters. Under the optimized conditions,the pyrolysis efficiency of carbon sources and the synthesis of DWCNTs have been improved. It is also found that the S/Fe ratio and the flow rate have a significant influence on the morphology and purity of the carbon nanotubes. The reason for the zone selectivity at different flow rate and the influence of the diameter-changed structure on the growth of DWCNTs were discussed as well. It is believed that the diameter-varied reactor may become a feasible route to the mass and continuous production of DWCNTs.

关 键 词：双壁碳纳米管 化学气相沉积 变径反应器 

分 类 号：TB383.1[一般工业技术—材料科学与工程]