Multi-wall carbon nanotubes supported on carbon fiber paper synthesized by simple chemical vapor deposition

2014 ◽  
Vol 187 ◽  
pp. 113-119 ◽  
Author(s):  
Ya-hao Li ◽  
Hong-quan Gao ◽  
Jian-hong Yang ◽  
Wen-liang Gao ◽  
Jia Xiang ◽  
...  
Author(s):  
Kinghong Kwok ◽  
Wilson K. S. Chiu

An open-air laser-induced chemical vapor deposition technique has been successfully used to rapidly deposit pillars of carbon nanotube forest on a moving glass substrate. A CO2 laser is used to heat a traversing fused quartz rod covered with metal particles inside a hydrocarbon environment. Pyrolysis of hydrocarbon precursor gas occurs and subsequently gives rise to the growth of multi-wall carbon nanotubes on the substrate surface. The experimental results indicate that nanotube growth kinetics and microstructure are strongly dependent on the experimental parameters such as laser power. The typical deposition rate of carbon nanotubes achieved in this study is over 50 μm/s, which is relatively high compared to existing synthesis techniques. At high power laser irradiation, carbon fibers and carbon film are formed as a result of excessive formation of amorphous carbon on the substrate. High-resolution transmission and scanning electron microscopy, and x-ray energy-dispersive spectrometry are used to investigate the deposition rate, microstructure and chemical composition of the catalytic surface and the deposited carbon nanotubes.


1999 ◽  
Vol 593 ◽  
Author(s):  
H. Cui ◽  
D. Palmer ◽  
O. Zhou ◽  
B. R. Stoner

ABSTRACTAligned multi-wall carbon nanotubes have been grown on silicon substrates by microwave plasma enhanced chemical vapor deposition using methane/ammonia mixtures. The concentration ratio of methane/ammonia in addition to substrate temperature was varied. The morphology, structure and alignment of carbon nanotubes were studied by scanning electron microscopy and transmission electron microscopy. Both concentric hollow and bamboo-type multi-wall carbon nanotubes were observed. Growth rate, size distribution, alignment, morphology, and structure of carbon nanotubes changed with methane/ammonia ratio and growth temperature. Preliminary results on field emission properties are also presented.


2003 ◽  
Vol 788 ◽  
Author(s):  
K. G. Belay ◽  
J Jackson ◽  
Yan Xin

ABSTRACTBoth carbon nanotubes and carbon nanofibers were grown on a thick nickel substrate by means of microwave plasma enhanced chemical vapor deposition (MPECVD) process using 20% CH4 and 80% H2 at a temperature of 750°C and a pressure of 50 Torr. The substrate was pre-abraded with 1.0μm diamond powder and 15.0 μm diamond paste to increase the rate of nucleation. When the substrate is taken out of the reactor the film detaches itself completely from the nickel. Unusual outgrowth structures appear jutted on one section of the substrate in a symmetrical manner. These structures were very hard and, when analyzed using environmental scanning electron microscope (ESEM), Raman microscopy and transmission electron microscope (TEM), micro-trees and an abundance of multi wall carbon nanotubes (MWCNTs) and nanofibers were observed. An attempt to measure the hardness of the film using a nano-indenter was inconclusive due to the extreme hardness of the material produced.


2006 ◽  
Vol 326-328 ◽  
pp. 333-336
Author(s):  
Yun Young Bang ◽  
Tae Jin Je ◽  
Kyung Hyun Whang ◽  
Won Seok Chang

Chemical vapor deposition (CVD) is one of the various synthesis methods that have been employed for CNT growth. In particular, Ren et al reported that large areas of vertically aligned multi-wall carbon nanotubes could be grown using plasma enhanced chemical vapor deposition (PECVD). In the present study, we synthesized aligned CNT arrays using a direct current (dc) PECVD system. The synthesis of CNTs requires a metal catalyst layer, etchant gas, and a carbon source. In this study, the substrate consisted of Si wafers with 10, 30, and 50 nm Ni-sputtered film. Ammonia (NH3) and acetylene (C2H2) were used as the etchant gases and carbon source, respectively. NH3 pretreatment was processed using a flow rate of 180 sccm for 10 min. CNTs were grown on pretreated substrates at 30% C2H2:NH3 flow ratios for 10 min. Carbon nanotubes with diameters ranging from 60 to 80 nanometers and lengths of about 2.7 μm were obtained. Vertical alignment of the carbon nanotubes was observed by FE-SEM.


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