【作者】 张红瑞；

【导师】 姚建铨； 梁二军；

【作者基本信息】 郑州大学 ， 凝聚态物理， 2003， 博士

【摘要】 轻元素B、C和N原子之间可以通过共价键结合形成稳定的化合物，具有丰富多变的成分配比、结构和物理性质，近年来开辟了材料科学中的一个极为活跃的领域。本文工作主要围绕纳米管制备及工艺参数优化，包括研究多壁碳纳米管、定向多壁碳纳米管、CN_X纳米管、BCN纳米管。在对碳纳米管制备的基础上，全面系统地研究了碳纳米管的影响因素，对热解法制备碳纳米管确定了可供参考的制备工艺参数，在些基础上，首次成功地直接在反应炉内石英管壁上直接生长分层生长的定向碳纳米管，为纳米管的性质的测量提供了一定的基础，而且为定向碳纳米管在微电子学领域的应用提供可能性，能成功地实现定向纳米管的固定长度生长。成功地以乙二胺为氮源制备出了CN_X纳米管和BCN纳米管，确定了两种纳米管生长的最佳工艺参数，同时指出拉曼光谱中可以同时用I_D／I_G、I_D^*／I_G和D带、G带、D^*带的半高宽度来定性地表征掺杂纳米管的缺陷。最后指出N原子的掺杂能有效地改善C纳米管的场发射性能，但BCN纳米管场发射性能较差。本文论文主要包括以下内容： 1．无序多壁碳纳米管的研究：在以二甲苯为碳源，以Ar（或N₂）和H₂为保护气体，采用单级加热的方法制备碳纳米管的基础上，着重优化了热解法制备碳纳米管时的工艺参数。结合透射电镜、扫描电镜及拉曼光谱，系统地研究了以钴／二茂铁为催化剂时不同温度下、以及在860℃时，分别以钴／二茂铁、镍／二茂铁、钴、镍／钴不同催化剂、不同保护气体对高温热解法制备的多壁碳纳米管结构、产率等的影响，对产物的形态、结构进行分析。得出制备温度为820℃～860℃，以钴／二茂铁为催化剂时所制备的碳纳米管的质量最好，而且并率最高；保护气体的种类（N₂或Ar）对碳纳米管的质量无明显的影响，但与H₂有一定的关系。与根据碳纳米管的物理、化学性质，提出了一种全新的碳纳米管纯化方法：先对制备的碳纳米管于500℃在空气中氧化30分钟，然后用18％的盐酸煮20分钟，最后将样品稀释，过滤，再用去离子水过滤3次，烘干，便可得到纯的碳纳米管。通过上述的分析，进一步研究在碳源高温热解环境下不同金属催化剂的性能及机理，并对不同条件下生成的碳纳米管的拉曼光谱进行了分析。 2．定向多壁碳纳米管阵列的研究：首次直接在加热炉内石英管内壁上成功的生成了分层生长的定向多壁碳纳米管阵列。为了优化定向碳纳米管阵列的制备，对生长温度及生长时间进行了研究。试验表明，反应温度对定向碳纳米管的形成具有决定性的影响，较适合定向碳纳米管生长的温度区域为800℃～900℃，随反应温度的升高，碳纳米管的直径略有加大。与生长温度相比，反应时间对所生成的纳米管的直径没有明显的影响，但是对定向纳米管的长度有决定性的作用，在碳纳米管生长开始时生长较慢，前40分钟内生长速率较大，而后随生长时间的增加，生长速率变缓，这可能是当定向纳米管的高度增大时，Co催化剂的挥发性减小，而且此时碳不能与铁催化剂充分接触所引起的。值得注意的是所有制备出的纳米管阵列都由许多独立的层组成，不同层之间由催化剂层隔开，这种结构可能是由前驱液注入不均匀引起。这说明通过合理控制生长的条件，可以实现定向碳纳米管的分层生长，而且可以控制前驱液注入的量来控制不同层的厚度决定定向碳纳米管不同层的长度。 3.CN、纳米管的热解法制备:利用与碳纳米管制备相同的工艺，.在对以氯化胺和乙二胺为氮源进行对比后，得出乙二胺为氮源时所制备出的CN、纳米管的“竹节状”结构更明显。然后，以NZ和玩为辅气，系统地研究了不同的催化剂、不同的温度等实验条件对CN、纳米管制备的影响。根据透射电子显微镜和扫描电子显微镜观察，分析了CN、纳米管的微观结构。得出当温度逐渐升高时，CN、纳米管的结构由“纳米铃”结构变为“竹节状”结构，得出在780℃时N掺杂量最高。二茂铁在纳米管的生长过程中有重要的作用，以催化剂钻和二茂铁配合作催化剂时催化效果最好。对所制备出的BCN纳米管进行了拉曼光谱分析，得出除D带以外，G带和D*带均与缺陷有关，指出可以用I汉Io、Io./IG和三个峰的半高宽度来表征纳米管的缺陷程度，但当纳米管中的N掺杂量太小时，Io边G的变化规律不太明显。 4.BCN纳米管的热解法制备:与CNx纳米管制备相同，首次以乙二胺、二茂铁和硼氢化钠为原料，以NZ和H:为辅气，制备出了具有竹节状结构的BCN纳米管。根据透射电子显微镜和扫描电子显微镜观察，分析了BCN纳米管的微观结构，扫描俄歇微探针分析表明，860℃时，以钻/二茂铁为催化剂时生成的BCN纳米管中B、C和N的原子比例为1 .7:%.8:1.5。系统地研究了制备温度、催化剂、不同催化剂配比时最佳制备温度、钻与二茂铁的催化活性比较、NZ及玩对制备BCN纳米管的影响。指出在温度为860℃附近，以钻/二茂铁或镍/二茂铁为催化剂，NZ的流量为120²0Osccm，HZ的流量为40sccm附近时制备的BCN纳米管的质量最好，产率也较高。在实验开始时，钻的催化性能相对来说小于二茂铁的催化性能。利用CN、纳米管中关于拉曼光谱的分析方法对其拉曼光谱进行了分?更多还原

【Abstract】 Study on the light element materials becomes a sparkling topic material research in recent years, because light element atoms can be covalently bounded to each other and form stable compounds, which have variable contents, structures, and physical properties. In this thesis, we will focus on the nanotube structure and synthesis, including disorder multi-wall carbon nanotube, aligned multi-wall carbon nanotube array, CNX nanotube, and BCN nanotube. The effects of growth parameters, which provide scientific basis for pyrolysis of carbon nanotube, were studied systematically. Furthermore, layered aligned multi-wall carbon nanotube arrays separate by catalyst particles were synthesized on the surrounding of reaction quartz tube by injection of xylene-ferrocene for the first time, which provided a chance for the accurate measure and potential use of carbon nanotubes. Layered carbon nanotube with special length could be synthesized with this method. CNX nanotube and BCN nanotube were obtained with ethylenediamine as nitrogen source, and the growth parameters were screened at the same time. We found that the value of ID/IG, ID*/IG and FWMH of three bands could be used to estimate the degree of disorder. The field emission property of carbon nanotubes could be increased by substitution of nitrogen for some of carbon, however, however, that of BCN nanotubes was poor.1. Study of disordered multi-wall carbon nanotubeCarbon nanotubes with different diameter distributions have been produced by thermal decomposition of a ferrocene-xylene mixture under different temperatures and different catalysts in an Ar (or N2)/H2 atmosphere. The effect of the growth temperature, catalyst, and’ the protection gases on the growth of carbon nanotubes were mainly studied with th help of TEM, SEM, and Raman spectroscopy. Carbon nanotubes with better quality and higher yield were synthesized at an appropriate temperature of 820C~860C and a catalyst of cobalt/ferrocene. There was no significant relation between the quality of carbon nanotube and protection gas. A new purified method for carbon nanotube was put forward.2. study of aligned multi-wall carbon nanotubeLayered multi-wall carbon nanotube arrays were synthesized firstly directly on the surrounding of the reaction quartz tube, in a Ar/H2 atmosphere by pyrolysis of ferrocene in xylene into a suitable reaction furnace with cobalt powder in. The effects of the growth temperature and duration on the growth of aligned carbon nanotube array were studied with the help of SEM and TEM. The experiments show that the reaction temperature significantly influenced the alignment of the MWNTs, and an appropriate reaction temperature for growth was 800C~900C. The diameter of the carbon nanotube increased a little with the growth temperature. Besides temperature, the reaction duration influenced the length of the well-aligned carbon nanotubes. There was no significant relation between the growth time and the diameter of the carbon nanotubes in the array. All of obtained array composed of many layers separated by catalyst particles. Those phenomenon may be due to non-uniform injection of feed. At last, a model of aligned carbon nanotube array were proposed.3. study of CNX nanotubeCNX nanotube were synthesis by thermal decomposition of ammonium chloride and ethylenediamine in an Na/Hfo atmosphere, respectively. We found that there is more "bamboo-shaped" in CNX nanotube made with ethylenediamine. The effect of growth temperature, catalyst, and content of ferrocene were studied systematically with the help of TEM. The "nanobelt" nanotube became to "bamboo-shaped" nanotube with the increase of growth temperature. CNX nanotube with higher concentration of nitrogen was obtained at 780C. The capability of catalyst following the sequence of Fe, Ni and Co. Ferrocene has key important role in the growth of CNX nanotube, especially with the help of cobalt. At the same time, Raman spectroscopy was used to studied the as-grown CNX nanotube. Besides the D band, both G band and D* band depend on更多还原