Vapor deposition carbon nanotubes

Multiwall carbon nanotubes (MWCNTs) have been synthesized by catalytic chemical vapor deposition (CCVD) of ethylene on several mesoporous aluminosilicates impregnated with iron. The aluminosilicates were synthesized by sol-gel method optimizing the Si/Al ratios from 6 to 80. The catalysts are characterized by nitrogen adsorption, X-ray diffraction, 27A1 NMR, thermogravimetric analysis (TGA) and infrared. The MWCNTs are characterized by TGA and transmission and scanning electron microscope. 

P. Coquay, E. Flahaut, E. de Grave, A. Peigney, R.E. Vandenberghe, and C. Laurent, Fe/Co alloys for the catalytic chemical vapor deposition synthesis of single- and double-walled carbon nanotubes (CNTs). 2. The CNT-Fe/Co-MgAl204 system. J. Phys. Chem. B 109, 17825-17830 (2005). 

The multiwalled nanotubes as well as the herringbone type carbon nanofibers were synthesized in-house in a quartz glass fluidized bed reactor via chemical vapor deposition (CVD). The method is described in detail elsewhere.19 The platelet nanofibers, in contrast, were purchased from the company FutureCarbon GmbH (Bayreuth, Germany). 

The approaches used for preparation of inorganic nanomaterials can be divided into two broad categories solution-phase colloidal synthesis and gas-phase synthesis. Metal and semiconductor nanoparticles are usually synthesized via solution-phase colloidal techniques,4,913 whereas high-temperature gas-phase processes like chemical vapor deposition (CVD), pulsed laser deposition (PLD), and vapor transfer are widely used for synthesis of high-quality semiconductor nanowires and carbon nanotubes.6,7 Such division reflects only the current research bias, as promising routes to metallic nanoparticles are also available based on vapor condensation14 and colloidal syntheses of high-quality semiconductor nanowires.15... 

Kouklin N, Tzolov M, Straus D, Yin A, Xu JM (2004) Infrared absorption properties of carbon nanotubes synthesized by chemical vapor deposition. Applied Physics Letters 85 4463 1465. 

Liu J, Czerw R, Carroll DL (2005a) Large-scale synthesis of highly aligned nitrogen doped carbon nanotubes by injection chemical vapor deposition methods. Journal of Materials Research 20 538-543. 

J. Campos-Delgado, I. 0. Maciel, D. A. Cuiien, D.J. Smith, A. Jorio, M. A. Pimenta, H. Terrones, M. Terrones, Chemical vapor deposition synthesis of N-, P-, and Si-doped singie-waiied carbon nanotubes, ACS Nano, vol. 4, pp. 1696-1702, 2010. 

Li, Y.-L., I.A. Kinloch, and A.H. Windle, Direct Spinning of Carbon Nanotube Fibers from Chemical Vapor Deposition Synthesis. Science, 2004. 304(5668) p. 276-278. 

The field emission properties of carbon nanotube forests and single nanotubes are described. Controlled emission is possible for aligned CNT arrays where the spacing is twice the CNT height, as grown by plasma enhanced chemical vapor deposition. This leads to the maximum field enhancement factor. For random forests, the field enhancement obeys an exponential distribution, leading to a lower emission site density and imperfect current sharing. Ballast resistors can help alleviate this problem. Random nanocarbons perform less well than CNTs. Some applications are covered. Elec-... 

Recently, the efficacy of LDHs as catalyst precursors for the synthesis of carbon nanotubes via catalytic chemical vapor deposition of acetylene has been reported by Duan et al. [72]. Nanometer-sized cobalt particles were prepared by calcination and subsequent reduction of a single LDH precursor containing cobalt(II) and aluminum ions homogeneously dispersed at the atomic level. Multi-walled carbon nanotubes with uniform diameters were obtained. 

Figure 3.16 Different steps in the fabrication of MWNT nanoelectrode arrays, (a) metal film deposition, (b) catalyst deposition, (c) plasma-enhanced chemical vapor deposition for CNT growth, (d) dielectric encapsulation with Si02, (e) planarization with a chemical mechanical polishing to expose the ends of the carbon nanotubes, (f) electrochemical characterization. Readapted from Ref [6].

Matlhoko L, Pillai SK, Moodley M et al (2009) A comparison of purification procedures for multi-walled carbon nanotubes produced by chemical vapor deposition. J Nanosci Nanotechnol 9 5431-5435... 

Generally, a carbon nanotube FET device is constructed by a substrate (gate), two microelectrodes (source and drain), and bridging material between the electrodes, which is typically an individual SWNT or a SWNT network. A SWNT FET is usually fabricated by casting a dispersion of bulk SWNTs or directly growing nanotubes on the substrate by chemical vapor deposition (C VD) either before or after the electrodes are patterned.64 Due to the diffusive electron transport properties of semiconducting SWNTs, the current flow in SWNT FET is extremely sensitive to the substance adsorption or other related events on which the sensing is based. 

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