The invention relates to the technical field of controlled preparation of carbon nanotubes, in particular to a floating catalyst chemical vapor deposition method for single-walled carbon nanotubes. With hydrogen as carrier gas, transition metal as catalyst and sulfur as growth promoter, trace water vapor was introduced into the reaction system to improve the catalytic efficiency of metal particle catalysts in the growth zone and prolong the lifetime of catalysts, so as to achieve high-purity and high-crystallinity growth of single-walled carbon nanotubes. Under the optimum conditions, the conversion efficiency of carbon source is very high, up to 25%; the diameter of carbon nanotubes is uniform, the crystallinity is high, the maximum concentration oxidation temperature is 816 C; the residual catalyst impurities are very few, and the content of catalyst is less than 1.1wt%. The method of the invention has both high efficiency of the preparation process and high quality of the product, provides an effective way for the large-scale preparation and industrialization development of high-quality single-walled carbon nanotubes, and has great significance for the large-scale application of high-quality single-walled carbon nanotubes.
【技术实现步骤摘要】
一种单壁碳纳米管的浮动催化剂化学气相沉积方法
本专利技术涉及碳纳米管的控制制备
,具体为一种高转化率生长高纯度、高结晶度单壁碳纳米管的浮动催化剂化学气相沉积方法。
技术介绍
单壁碳纳米管可看作是由单层石墨烯沿一定方向卷曲而成的无缝中空管状结构。这种结构的独特性使得单壁碳纳米管具有优异的力学性能、手性依赖的导电属性、弹道输运特性、优异的柔韧性及高化学稳定性等,可望在航空、航天、纳电子器件等高
获得广泛应用。然而,要实现单壁碳纳米管在以上领域的应用,首先需要解决的瓶颈问题是高纯度、高质量的单壁碳纳米管的宏量、低成本制备。化学气相沉积技术因工艺和设备简单、成本低廉、结构可控等优势,已成为目前制备单壁碳纳米管的主流方法。化学气相沉积法控制制备宏量单壁碳纳米管的工艺主要分为两大类,即担载法和浮动催化剂化学气相沉积法。已商业化生产的碳纳米管的制备主要采用担载法,即将催化剂浸渍/涂覆于某种基体上,如:多孔沸石、MgO、硅基片等,在适当的温度和碳源供给条件下,碳纳米管可从基体担载的催化剂上生长。采用这种方法制得的碳纳米管通常为粉末样品,其长度较短、多呈弯曲状、质量较低、需要后续处理去除担载催化剂的载体(文献1:ZhaoMQ,ZhangQ,HuangJQ,NieJQ,WeiF.Layereddoublehydroxidesascatalystsfortheefficientgrowthofhighqualitysingle-walledcarbonnanotubesinafluidizedbedreactor.Carbon,2010,48:3260–3270。文 ...
【技术保护点】
1.一种单壁碳纳米管的浮动催化剂化学气相沉积方法,其特征在于,以氢气为载气,甲苯和乙烯为碳源,金属茂化物和噻吩分别作为催化剂和生长促进剂的前驱体,将金属茂化物和噻吩溶于甲苯中形成混合溶液,将混合溶液匀速注入反应腔体,并在氢气为载气的携带下进入反应区,同时通入乙烯和痕量水蒸气,进行碳纳米管的生长。
【技术特征摘要】
1.一种单壁碳纳米管的浮动催化剂化学气相沉积方法,其特征在于,以氢气为载气,甲苯和乙烯为碳源,金属茂化物和噻吩分别作为催化剂和生长促进剂的前驱体,将金属茂化物和噻吩溶于甲苯中形成混合溶液,将混合溶液匀速注入反应腔体,并在氢气为载气的携带下进入反应区,同时通入乙烯和痕量水蒸气,进行碳纳米管的生长。2.按照权利要求1所述的单壁碳纳米管的浮动催化剂化学气相沉积方法,其特征在于,氢气流量为3000~5000sccm,甲苯、金属茂化物、噻吩混合溶液中,三者质量比为100:3~8:1.2~1.8,混合溶液注入反应腔体的速率为0.7~1.1ml/h,乙烯流量为5~20sccm,水蒸气在反应区中的浓度为0.1~10ppm,反应区温度为1100~1500℃。3.按照权利要求2所述的单壁碳纳米管的浮动催化剂化学气相沉积方法,其特征在于,优选的,水蒸气在反应区中的浓度为0.5~3.5ppm。4.按照权利要求1所...
【专利技术属性】
技术研发人员:刘畅,石超,侯鹏翔,成会明,
申请(专利权)人:中国科学院金属研究所,
类型:发明
国别省市:辽宁,21
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