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1.
A great amount of research on carbon nanotubes (CNTs) has been carried out since its observation in 19911. It has been predicted that CNTs can be novel materials of semiconductor, electric-field-induced electron emitters, quantum wire, catalysts etc2-5. Nowadays, CNTs can be synthesized by arc discharge6 laser ablation7, and pyrolysis of hydrocarbon gases8. In order to make CNTs of practical importance, the criteria for assessing any synthesis technique must include the feasibility and po…  相似文献   

2.
A technique has been developed to grow carbon nanotubes by flowing acetylene over pre‐reduced LaCoO3 catalyst in a fluidized‐bed catalytic reactor. Carbon nanotubes were characterized by means of SEM and TEM. The pre‐reduced LaCoO3 catalyst was found to be effective in producing carbon nanotubes with even diameter. The effects of reduction temperature of LaCoO3 on the growth of carbon nanotubes were investigated. This process can easily be scaled up.  相似文献   

3.
利用沸腾床反应器制备碳纳米管   总被引:7,自引:0,他引:7  
碳纳米管自1991年被日本NEC的Iijima发现以来,已经引起物理、化学和材料科学领域学者的广泛关注,并成为研究热点,理论和实验研究表明,碳纳米管具有独特的电学和力学性质,其导电性与管本身的直径和管的螺旋度有关,随着这些参数的变化,碳纳米管可表现出导体或半导体的性质。扬氏模量的测量表明,碳纳米管具有极高的强度,这些都预示着它具有广泛的应用前景。  相似文献   

4.
碳纳米管的纯化──电化学氧化法   总被引:13,自引:0,他引:13  
用电化学氧化法对碳纳米管进行纯化,从稳态极化曲线出发,对反应的可行性进行了分析,考察了支持电解质、电流密度、时间等因素对反应的影响,确定了最佳实验条件,同时对纯化机理进行了解释.  相似文献   

5.
脉冲激光溅射下固液界面生长的碳纳米管及其机理初探   总被引:1,自引:0,他引:1  
以脉冲激光束直接溅射浸在水中的单质碳样品,发现在固液界而也能产生碳纳米管.实验还发现碳纳米管的形成与样品的结构有密切的关联:石墨的层状结构越完整,碳纳米管的形成越容易,而且石墨层而相对于激光束的取向也会显著地影响碳纳米管的生成.通过对实验结果的分析,探讨了激光液相溅射产生碳纳米管的机理,认为激光溅射产生的碳蒸气被水束缚在固液的界而内,而完整的晶而使碳蒸气在界而内的分布具有准二维的性质,为碳纳米管的生长提供了较为理想的环境.  相似文献   

6.
脉冲激光溅射下固液界面生长的碳纳米管及其机理初探   总被引:3,自引:0,他引:3  
以脉冲激光束直接溅射浸在水中的单质碳样品,发现在固液界面也能产生的碳纳米管,实验还发现碳纳米管的形成与样品的结构有密切的关联:石墨的层状结构越完整,碳纳米管的形成越容易,而且石墨层面相对于激光束的取向也会显著地影响碳的生成。  相似文献   

7.
Carbon nanotubes were initially chemically modified with an H2SO4-HNO3 treatment, and subsequently activated with Pd-Sn catalytic nuclei via a one-step activation approach. These activated nanotubes were used as precursors for obtaining gold nanoparticles-attached nanotubes via simple electroless plating. This approach provides an efficient method for attachment of metal nanostructures to carbon nanotubes. Such novel hybrid nanostructures are attractive for many applications.  相似文献   

8.
碳纳米管的激光溅射产生   总被引:1,自引:0,他引:1  
碳纳米管的激光溅射产生程大典,余荣清,刘朝阳,张强,王育煌,黄荣彬,詹梦熊,郑兰荪(固体表面物理化学国家重点实验室,厦门大学化学系,厦门,361005)关键词碳纳米管,激光溅射,碳球Smalley等[1]曾以脉冲激光束在超声分子束喷口的喉道处蒸发石墨...  相似文献   

9.
Single and double layered MoS2-coated multiwalled carbon nanotubes (MWCNs) were successfully prepared by pyrolyzing (NH4)2MoS4-coated multiwalled carbon nanotubes in an H2 atmosphere at 900℃. MoS2-coated MWCNs would be expected to have different tribological and mechanical properties compared to MoS2, so it may have potential applications in many fields.  相似文献   

10.
张新胜  丁平 《电化学》1998,4(3):334-339
苯在固定电化学反应氧制备对苯二醌,阳极和阴极分别为多孔铅合金和铅粒。是解液是1mol/l硫酸水溶液,苯分散于电解液中。最佳电解条件:电解液流速u=0.19m.s^-1,反应器厚度L=10mm,电极电位E=1.6V,电流I=10A和苯含量CB=24%,电流效率CE是62.9%。  相似文献   

11.
碳纳米管负载铂催化剂的制备、结构及电化学加氢特性   总被引:6,自引:0,他引:6  
采用浸渍沉淀法制备Pt/CNTs和Pt/C催化剂,并对其结构及电催化性能进行比较,表征.实验表明,以碳纳米管作催化剂载体可使催化剂的负载量,载体上铂的分散度以及其活性中心大大提高.与Pt/C(JohnsonMatthey)催化剂相比,Pt/CNTs的电化学性能表现出更大的活性.碳纳米管作为阴极材料在质子交换膜燃料电池加氢反应器合成化学品中的作用十分明显.  相似文献   

12.
碳纳米管在电分析中的应用   总被引:10,自引:0,他引:10  
碳纳米管因其独特的特性,自发现以来得到了广泛的关注与应用;本文着重对碳纳米管在电分析中的应用作了综述。  相似文献   

13.
纳米碳管的制备   总被引:6,自引:0,他引:6  
纳米碳管是一种新型的纳米材料和碳分子,其独特的分子结构和性能引起了人们的广泛关注。本文综述了纳米碳管的几种制备方法和相关的生长机理。  相似文献   

14.
This work reports the advantages of using glassy carbon electrodes modified with multiwall carbon nanotubes (MWCNT) dispersed in polyethylenimine (PEI). The presence of MWCNTs wrapped by PEI largely facilitated the strong adsorption of uric acid (UA) and allowed its highly sensitive and selective quantification even in the presence of high excess of ascorbic acid. The selected conditions for the electrochemical sensing were 5 s accumulation at ?0.300 V under stirring and quantification in a 0.050 M phosphate buffer solution pH 7.40 by differential pulse voltammetry adsorptive‐stripping after medium exchange. The platform allowed the successful application in the quantification of UA in urine.  相似文献   

15.
甲烷在流态化催化剂床裂解生长多壁碳纳米管;多壁碳纳米管;Ni-Mg-O催化剂;甲烷;流化床;催化化学蒸汽沉积法  相似文献   

16.
Interest in carbon nanotubes (CNT) has grown at a very rapid rate in the last decade. Their interesting physical and chemical properties open attractive possibilities in many application areas. These properties depend on the process conditions during synthesis and on subsequent purification steps. Recent studies have demonstrated that CNT can promote the electron transfer of biomolecules. These exceptional properties make them attractive for use in electrochemical biosensors. Multi walled nanotubes have been synthesized by the Chemical Vapor Deposition (CVD) method using methane as a carbon source and Ni–Al2O3–SiO2 as the catalyst. The influence of the variation of certain reaction parameters such as feed gas composition, catalyst mass, temperature and reaction time in the yield of the CVD process has been established. In addition, the structural and chemical characteristics of the CNTs have been studied and a purification process to eliminate the catalyst and amorphous carbon has been developed that involves a gaseous oxidative process and acid treatment. The efficiency of the purification step has been determined by analytical techniques. Atomic force microscopy, Raman scattering, thermogravimetric analysis, inductively coupled plasma atomic spectroscopy are the characterization techniques employed in this work.  相似文献   

17.
Carbon nanotubes, which was discovered by Iijima1 in 1991, is the most typical one-dimensional nano-material with the micrometers order in length and nanometers order in diameter. CNTs are composed of graphitic sheets rolled into closed concentric cylinders, and classed into single wall nanotubes and multi-wall nanotubes. CNTs can offer many significant advantages over most existing materials. Since its discovery, unprecedented interest has been stimulated because of its significance both in…  相似文献   

18.
模拟移动床色谱技术及其应用   总被引:9,自引:0,他引:9  
详细地介绍了一种现代化分离技术模拟移动床色谱技术的发展历史及其工作原理,同时介绍了模拟移动床色谱在石油化工、糖醇分离、手性化合物及其他方面的主要应用。  相似文献   

19.
碳纳米管贮氢研究进展   总被引:4,自引:0,他引:4  
唐水花  张良辅  于作龙 《化学通报》2003,66(10):687-695
综述了碳纳米管在实验和理论方面的贮氢研究工作。不同科研工作者得到的实验结果很不一致,重量百分比分布在67%~0.01%之间。理论模拟结果差别相对小一些。碳纳米管中的氢吸附受有效表面积和孔体积的强烈影响,单壁碳纳米管堆积的几何形状在氢吸附中也起着重要作用。不少研究者认为碳纳米管并不是适合的贮氢材料。其贮氢量在1(wt)%以下。  相似文献   

20.
Single-Walled Carbon Nanotubes (SWCNTs) possess a wealth of exceptional structural, mechanical and electronic properties. These have made them potentially useful for applications in nanotube-reinforced materials, nanoelectronic devices, field emitters, probe tips for SPM, as well as for sensors, biosensors, and actuators. However, manipulation and processing of SWCNTs has been limited by their insolubility in most common solvents, although some dissolution has recently been obtained. Their chemical modification might pave the way to many useful applications, including the preparation of composite materials or the immobilization of biological molecules as enzymes (i.e., for biosensors and electrochemical sensors). Attachment of oxygen-containing functional groups (i.e., carboxy groups, carbonyl groups, hydroxy groups, etc.) on the surface of the carbon nanotubes could be achieved using different pretreatments of the nanostructured material. These involved (a) chemical and physical procedures; and (b) electrochemical functionalization. Different attempts at sidewall modification have been hampered by the presence of significant contaminants as graphitic and amorphous carbon or have required solubilization via chemical reactions on the ends of cut nanotubes. A more accommodating and direct approach to functionalize nanotubes is therefore required. We report here the sidewall functionalization of purified SWCNTs, obtained by different approaches and finally, we can discuss possible applications of functionalized SWCNTs in the sensing area.  相似文献   

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