Catalytic activity of K10 montmorillonite in the chemical vapor deposition of multi-wall carbon nanotubes from methane

2021 ◽  
Vol 211 ◽  
pp. 106178
Author(s):  
Maciej Gubernat ◽  
Marcel Zambrzycki
Keyword(s):  
Carbon Nanotubes ◽  
Catalytic Activity ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Multi Wall Carbon Nanotubes

Synthesis of Carbon Nanotubes on a Moving Substrate by Laser-Induced Chemical Vapor Deposition

2005 ◽  
Author(s):  
Kinghong Kwok ◽  
Wilson K. S. Chiu
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Deposition Rate ◽  
Vapor Deposition ◽  
Substrate Surface ◽  
Carbon Film ◽  
Chemical Vapor ◽  
Multi Wall Carbon Nanotubes ◽  
Vapor Deposition Technique ◽  
Synthesis Of Carbon Nanotubes

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.

scholarly journals Synthesis of Carbon Nanotubes by Plasma-Enhanced Chemical Vapor Deposition Using Fe1−xMnxO Nanoparticles as Catalysts: How Does the Catalytic Activity of Graphitization Affect the Yields and Morphology?

2019 ◽  
Vol 5 (3) ◽  
pp. 46 ◽  
Author(s):  
Takashi Yanase ◽  
Takuya Miura ◽  
Tatsuya Shiratori ◽  
Mengting Weng ◽  
Taro Nagahama ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Catalytic Activity ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Thermal Cvd ◽  
Catalytic Function ◽  
Yield And Quality ◽  
Synthesis Of Carbon Nanotubes

The choice of a catalyst for carbon nanotube (CNT) growth is critical to controlling the morphology and chirality of the final product. Plasma-enhanced chemical vapor deposition (PECVD) can alleviate the requirements of the catalyst, i.e., they must be active for both the decomposition of the source gas and graphitization in the conventional thermal CVD. However, it is still not well understood how the catalytic activity of the graphitization affects the yield and quality of CNTs. In this paper, we systematically investigated the influence of the catalytic activity of graphitization by tuning the composition of Fe1−xMnxO (x = 0–1) nanoparticles as catalysts. As the Mn component increased, the number of CNTs decreased because Mn has no catalytic function of the graphitization. The quality of CNTs also affected by the inclusion of the Mn component. Our study may provide useful information to develop a new catalyst for CNT growth in PECVD.

Aligned Carbon Nanotubes Via Microwave Plasma Enhanced Chemical Vapor Deposition

1999 ◽  
Vol 593 ◽  
Author(s):  
H. Cui ◽  
D. Palmer ◽  
O. Zhou ◽  
B. R. Stoner
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Silicon Substrates ◽  
Multi Wall Carbon Nanotubes ◽  
Field Emission Properties ◽  
Transmission Electron

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.

Carbon Nanotubes and Nanofibers Grown by Microwave Plasma Enhanced Chemical Vapor Deposition on a Nickel Substrate

2003 ◽  
Vol 788 ◽  
Author(s):  
K. G. Belay ◽  
J Jackson ◽  
Yan Xin
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Electron Microscope ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Diamond Powder ◽  
Environmental Scanning ◽  
Nickel Substrate ◽  
Multi Wall Carbon Nanotubes

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.

Synthesis of Vertically Aligned Carbon Nanotubes by dc PECVD

2006 ◽  
Vol 326-328 ◽  
pp. 333-336
Author(s):  
Yun Young Bang ◽  
Tae Jin Je ◽  
Kyung Hyun Whang ◽  
Won Seok Chang
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Carbon Source ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Catalyst Layer ◽  
Metal Catalyst ◽  
Synthesis Methods ◽  
Multi Wall Carbon Nanotubes ◽  
Vertically Aligned

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.

In-situ Plasma Diagnosis of Chemical Species in Microwave Plasma-assisted Chemical Vapor Deposition for the Growth of Carbon Nanotubes Using CH4/H2/NH3 Gases

2000 ◽  
Vol 621 ◽  
Author(s):  
Y.S. Woo ◽  
I.T. Han ◽  
N.S. Lee ◽  
J.E. Jung ◽  
D.Y. Jeon ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Low Temperature ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Carbon Sources ◽  
Chemical Species ◽  
Chemical Vapor ◽  
Optical Emission ◽  
Multi Wall Carbon Nanotubes

ABSTRACTSynthesis of multi-wall carbon nanotubes (MWNTs) was attempted by microwave plasma enhanced chemical vapor deposition using CH4/H2/NH3 gases on Ni/Cr-coated glass at low temperature. The synthesis was investigated by optical emission spectroscopy and quadrupole mass spectroscopy. It was observed that MWNTs could be grown within a very restrictive range of gas compositions. An addition of a small amount of NH3 resulted in a decrease of C2H2, which can be used to estimate the amount of carbon sources in plasma for the growth of MWNTs, and an increase of CN and Hα radicals acting as etching species of carbon phases. These results show that carbon nanotubes can be grown only under an appropriate condition that the growing process surpasses the etching process. The optimum C2H2 /Hα ratio in a gas mixture was found to be between 1 and 3 for the MWNT growth at low temperature.

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