Self-assembling of multi-walled carbon nanotubes on a porous carbon surface by catalyst-free chemical vapor deposition

Lin, Jarrn-Horng; Chen, Ching-Shiun; Ma, Hongchao; Chang, C. M.; Hsu, Chen-Yin; Chen, Hsiu-Wei

doi:10.1016/j.carbon.2008.06.050

Cited by 43 publications

(17 citation statements)

References 15 publications

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“…The shell created by the segregation of the R S species to the surface periphery from the bulk of them was amorphous, which led to nanotube growth. That carbon black substrate, like a FECA that exhibits amorphous (semi-amorphous, amorphous-like) surface periphery, mediates nanotube growth is evident from an experiment by Lin et al [48] Figure 2(b) by these authors shows the creation of shells prior to the growth of MWCNTs at 800 °C from them (e.g., the shells) and from the dissociation of diluted ethylene on carbon black substrate. These shells are obviously amorphous, as carbon black itself is amorphous.…”

Section: Communicationmentioning

confidence: 79%

Thermodynamic Imbalance, Surface Energy, and Segregation Reveal the True Origin of Nanotube Synthesis

Mohammad¹

2012

Advanced Materials

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Extensive analyses of thermodynamic imbalance, surface energy, and segregation of nanotubes on nanoparticle surfaces are performed. A model for surface energy i developed. In addition, nanotube growth both by vapor-phase and solid-phase mechanisms is described. Segregation of the nanotube species to the periphery of the nanoparticle, the creation of an amorphous shell at this periphery, a droplet created in this shell, and the mediation of this droplet for supersaturation and nucleation of the nanotube species may be the true causes of nanotube growth.

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Section: Communicationmentioning

confidence: 79%

Thermodynamic Imbalance, Surface Energy, and Segregation Reveal the True Origin of Nanotube Synthesis

Mohammad¹

2012

Advanced Materials

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“…This breakthrough opens a new insight into the growth mechanisms of CNTs: the explanation of CNTs growth over metal catalysts with lower carbon solubility needs to be studied intensively. Moreover, the growth of CNTs can also be achieved through metal-free routes on different substrates, such as porous carbon, 11 SiO 2 nanoparticles (NPs), 12,13 and nano diamond. 14,15 A vapor-solid surface-solid (VSSS) model is proposed for the growth of single-walled CNTs (SWNTs).…”

Section: Introductionmentioning

confidence: 99%

Self-assembly formation of multi-walled carbon nanotubes on gold surfaces

et al. 2010

Self Cite

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We report on the observation of self-assembled carbon nanostructures on a standard transmission electron microscopy (TEM) Au substrate formed via thermal chemical vapor deposition. Multi-walled carbon nanotubes (MWNTs) and other carbon nanostructures (CNs), such as carbon nanofibers and carbon nanoparticles (NPs), could be fabricated through structural transformation of metastable carbon layers on the Au surface during 800-850 °C with the thermal decomposition of ethylene. At these temperatures, we found that Au NPs will form immediately through the structural transformation of the Au grid surface in helium atmosphere. The Au NPs work as active centers to trigger the decomposition of ethylene into carbon atoms, which form metastable carbon layers or amorphous carbon nanobugs, and then form CNs via self-assembling. The growth of CNs was characterized by field-emission scanning electron microscopy (SEM), high-resolution TEM and RAMAN spectroscopy. The transformation of amorphous carbon nanobugs by electron beam irradiation is also recorded by in situ monitoring of TEM.

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“…An alternative possibility for non‐catalytic MWCNT formation, as a result of epitaxial growth on the inner surfaces of the pores in a solid carbon material, has been reported previously . This growth model implies that the nanometer‐scale curvature of the inner surfaces of the pores plays a key role in the nanotube formation.…”

Section: Discussionmentioning

confidence: 92%

“…Alternative methods for CNT synthesis without metal catalyst should be developed to meet these practical demands. Recently, a few techniques of catalyst‐free CNT synthesis have been reported . These methods suffer from several disadvantages; a dramatically low synthesis yield, a high (above 1400 °C) synthesis temperature, and the requirement of expensive SiC substrates …”

Section: Introductionmentioning

confidence: 99%

Growth of a Carbon Nanotube Forest on Silicon using Remote Plasma CVD

Исмагилов

Shvets

Zolotukhin

2013

Chemical Vapor Deposition

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CVD enhanced by remote plasma is applied to produce carbon film material on silicon substrates. The layers of aligned multiwall carbon nanotubes (MWCNT) are obtained without a metal catalyst by deposition from a methane/hydrogen gas mixture activated by a direct current (DC) discharge. The individual MWCNTs in the films consist of 4-7 concentric carbon shells with a spacing of 0.34 nm. An absence of metallic impurities in the MWCNT film material is confirmed using energy dispersive X-ray (EDX) and electron energy loss spectroscopy (EELS) analyses. A proposed model explains the formation of the cylindrical seeds of the MWCNTs via condensation of carbon atoms from the activated gaseous environment on the inner surfaces of pores, created in the substrate material as a result of silicon etching by ionized hydrogen, generated in the DC discharge plasma. Further growth of these seeds during the CVD process leads to the formation of MWCNT forests.

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Self-assembling of multi-walled carbon nanotubes on a porous carbon surface by catalyst-free chemical vapor deposition

Cited by 43 publications

References 15 publications

Thermodynamic Imbalance, Surface Energy, and Segregation Reveal the True Origin of Nanotube Synthesis

Thermodynamic Imbalance, Surface Energy, and Segregation Reveal the True Origin of Nanotube Synthesis

Self-assembly formation of multi-walled carbon nanotubes on gold surfaces

Growth of a Carbon Nanotube Forest on Silicon using Remote Plasma CVD

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