【作者】 陈林涛；

【导师】 莫育俊；

【作者基本信息】 河南大学 ， 光学， 2004， 硕士

【摘要】 碳纳米管是继C₆₀、C₇₀发现后碳族科学研究中的又一个惊喜。碳纳米管的发现具有十分深远的意义。首先，它是一种人工合成的准一维量子线，为开展低维材料的基础研究打开了方便之门。它不仅丰富了人们对自然界中这一最为寻常的元素的认识，并且由于它所具有的奇异结构、力学及电学性质，使它正逐步被应用于纳米电子器件、功能材料、燃料电池等领域。可以推测，随着人们对碳纳米管认识和应用的不断深入，它有可能对人类未来的生活产生深刻的影响。因此碳纳米管的发现被认为是二十世纪末最重要的发现之一，从而引起了世界各国政府、研究机构和工商界的广泛关注和浓厚兴趣。目前这一领域的研究已成为材料科学、凝聚态物理和化学界研究的前沿和热点。 拉曼散射是研究碳纳米管的有力手段之一，对于了解碳纳米管的结构及其物理内涵具有重要的作用。尤其是表面增强拉曼光谱具有很高的灵敏度，使我们能够得到更多的信息，对于揭示碳纳米管的内在性质和结构提供了正常拉曼光谱所不能提供的信息。 本论文有以下六部分组成： 一：介绍了碳纳米管的发现、结构及相关的制备方法。碳纳米管由于其纳米尺寸和独特的成键结构，使得它具有许多优异的性能。这些优异的性能主要体现在五个方面：碳纳米管的力学性能、电学性能、场发射性能、氢存贮、以及碳纳米管的电化学性能。 二：介绍了拉曼散射的基本概念、基本特征和拉曼散射中涉及到的一些基本参量。说明了拉曼散射技术在表征物质结构中的重要应用。另外还叙述了表面增强拉曼散射的发展历史、增强机制及应用。河南大学光学专业2001硕士论文 三.研究了在两种不同激发波长下的单壁碳纳米管的拉曼光谱，用457.5nm和632.8nrn两种不同的激发光分别测得了单壁碳纳米管的正常拉曼光谱和共振拉曼光谱。通过理论分析，得到了单壁碳纳米管的直径分布和进一步推测了其类型及结构参数。对单壁碳纳米管的正切拉伸模的成分进行了归属，在632.8nm激发波长下得到了IG/Io值的随激光功率变化曲线。重新对D模的振动进行了归属。在用457.5lun波长激发的单壁碳纳米管的拉曼谱中首次发现了1421cm一’的新峰。四.在单壁碳纳米管的低温拉曼光谱测量过程中，发现RBM和GM的拉曼频移在低温下的温度效应和在高温时的温度效应存在着很大的区别，且特征峰的强度的变化是不可逆的。五.研究了单壁碳纳米管沉积在不同增强衬底上面的表面增强共振拉曼光谱，在常温下，拉曼信号的强度主要来自于电磁增强效应的贡献。但是，通过单壁碳纳米管分子和金属衬底之间的相互作用也有一部分拉曼信号来自于所谓的化学增强的贡献。六.对单壁碳纳米管的纯化工作进行了讨论，我们采用了物理和化学方法相结合的方式来纯化单壁碳纳米管。并用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，说明了此方法的纯化效果。用6犯.stun波长的激发光测得了纯化前后的单壁碳纳米管的拉曼光谱，通过比较谱峰的频移及形状，分析了纯化对单壁碳纳米管结构的影响。更多还原

【Abstract】 Carbon nanotubes are another gratifying discovery succeeding C60 and C70 in carbon group scientific research, which is of profound significance. Firstly, it is a kind of man-synthesized quasi-one-dimensional quantum wires and facilitates the basic research of low dimensional materials. Not only does it enrich people’s perception of this common element in nature, but also it is gradually applied in the fields of nano-electronic device, function materials, fuel cell, etc due to its special structure, mechanics and electrics properties. It can be conjectured that with the perception and application of carbon nanotubes deepening, it will probably have great impact on human being’s future. Therefore, carbon nanotubes are regarded as one of the greatest discoveries at the end of twentieth century, and arouses wide attention and interest in all countries’governments, research bodies and industrial commercial world. So far researches in this field have become the front edge and hot spot of material science, condensed matter physics, chemistry.Raman scattering is one of powerful means to investigate carbon nanotubes and plays an important role in understanding their structure and physical meaning. Especially, The strong enhancement of the Raman signal by SERS opens up exciting opportunities for studying the Raman spectrum of a small number of nanotubes, and, maybe, even single nanotube, which provides the information that normal Raman spectrum can not supply to retrieve the intrinsic properties and structures of carbon nanotubes.The paper consists of the following six parts:I . In Part one , the discovery, structure and making method of carbon nanotubes are introduced. Due to its nanosize and unique bonding structure, carbon nanotubes have many outstanding properties which are reflected in the following five aspects: mechanics properties, electrics properties, field emission ,hydrogen storage and electrochemistry properties of carbon nanotubes.II . In Part two, the basic notion, properties of Raman scattering and the parameters involved in Raman scattering are introduced, and the important application of Raman scattering in characterization of material structure is also expounded. The history, enhancement mechanism and application of SERS are recounted as well.III. In part three, the normal Raman and resonant Raman scattering spectra of Single-walled carbon nanotubes are measured at 457.5nm and 632.8nm laser excitation wavelength. By theoretical analysis, the diameter distributions of SWNTs were obtained, style and configuration parameter were speculated furtherly. The components of the tangential stretch mode of SWTNs are assigned, the variational curve of the value of Ig / Id changed with laser power is obtained at 632.8nm excitation, the vibration of D mode is assigned renewedly. In the Raman scattering spectra of SWNTs which was measured using 457.5nm excitation, the new Raman peak at 1421cm’1 is discoveried for the first time.IV. In part four, the results of cryogenic raman spectra investigation show temperature dependence of RBM and GM at low temperature is greatly different from at high temperature, and the intensity of most feature is not reversible at low temperature.V. In part five, the SERRS spectra of SWNTs adsorbed on different metal substrates are studied, Under the normal temperature, the dominant contribution to the enhancement of the Raman single comes from strongly enhanced optical fields in thevicinity of the metallic nanostructures(electromagnetic SERRS enhancement). In general, the SERRS enhancement can also get a contribution from a so-called "chemical" SERS enhancement mechanism, which is based on the specific interaction between the target molecule and the metal substrate.VI . In part six, the purification of SWNTs is discussed and physics-chemistry-connected methods to purify SWNTs are put forward, the surface shapes of SWNTs before and after purification using scanning electron microscopy(SEM) is analyzed and the the purifying effe更多还原