Thin-film metal catalyst for the production of multi-wall and single-wall carbon nanotubes

Lacerda, R. G.; Teo, K. B. K.; Teh, A. S.; Yang, MinHo; Dalal, S. H.; Jefferson, D. A.; Durrell, John; Rupesinghe, N. L.; Roy, Debdulal; Amaratunga, G. A. J.; Milne, W. I.; Wyczisk, F.; Legagneux, Pierre; Chhowalla, Manishkumar

doi:10.1063/1.1794359

Cited by 39 publications

(23 citation statements)

References 28 publications

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“…Transition metals (Fe, Co, Ni) with an addition of Al under-layer have been demonstrated an efficient way to grow SWNTs by thermal CVD at high temperature. [25][26][27][28][29] The partially-oxidized Al under-layer (i.e., Al x O y ) provides both large support areas and high surface roughness to prevent the nanoparticles from forming large size particles at high temperatures, thus enhancing the yields of SWNTs growth. [25][26][27][28][29] For the bi-layered thin-film catalysts used in this study, we have also confirmed the formation of Al x O y after the preannealing process by characterization tools such as X-ray photoelectron spectroscopy (XPS, data not shown).…”

Section: The Dry Catalyst Systemsmentioning

confidence: 99%

Low Temperature Synthesis of Single-Walled Carbon Nanotubes in an Inductively Coupled Plasma Chemical Vapor Deposition System

Weng

Yang²,

Lin³

et al. 2008

j nanosci nanotechnol

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In this work, we present a parametric study on the low temperature synthesis of single-walled carbon nanotubes (SWNTs) in an inductively coupled plasma (ICP) CVD system using dry bi-layered catalytic thin-films (Fe/Al and Ni/Al, deposited by electron-beam evaporation method) as the catalysts. With a low substrate temperature of 550 degrees C and above, SWNTs were successfully synthesized on both catalysts, as revealed from the characteristic peaks of SWNTs in the micro-Raman spectra. By the reduction of plasma power and the shortening of the process times, the lowest synthesis temperature of SWNTs achieved in our system was approached to 500 degrees C on Ni/Al catalysts; on the other hands, the lowest temperature for Fe/Al catalysts was 550 degrees C. Our results suggest that as compared with Fe/Al, Ni/Al is more favorable for plasma-enhanced CVD (PECVD) synthesis of SWNTs at low temperatures. This work can be used for further improvements and better understanding on the production processes of SWNTs by PECVD methods.

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Section: The Dry Catalyst Systemsmentioning

confidence: 99%

Low Temperature Synthesis of Single-Walled Carbon Nanotubes in an Inductively Coupled Plasma Chemical Vapor Deposition System

Weng

Yang²,

Lin³

et al. 2008

j nanosci nanotechnol

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“…[9][10][11][12][13] The catalysts for synthesis of VACNTs are commonly prepared by sputtering or evaporating a thin metal film onto a substrate, [14,15] which dewets to form catalyst nanoparticles at an elevated temperature prior to growth. [16][17][18] While these catalysts are easily prepared and patterned by shadow masking or lithography, [7,14] these approaches are not easily able to create nanocluster catalysts that have monodisperse diameters and quantifiable areal densities. In thin metal films, both the nanocluster size and areal density are coupled to the film thickness, and the annealing procedure affects the size, density, and the chemical state of the nanoclusters.…”

mentioning

confidence: 99%

Controlling the Morphology of Carbon Nanotube Films by Varying the Areal Density of Catalyst Nanoclusters Using Block‐Copolymer Micellar Thin Films

2006

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In spite of much research progress in the science and synthesis of carbon nanotubes (CNTs), [1] control over the location and orientation of CNTs on substrates remains a major challenge. A key breakthrough was the synthesis of vertically aligned CNT (VA-CNT) arrays using thermal chemical vapor deposition (CVD) [2][3][4][5][6][7] and plasma-enhanced CVD, [8] where the CNTs self-orient perpendicular to the substrate surface due to initial crowding and continue to grow upward in this direction. These CNT arrays have wide-ranging applications, including membranes, heat dissipation, electrical interconnects, and nanoelectronics. [9][10][11][12][13] The catalysts for synthesis of VACNTs are commonly prepared by sputtering or evaporating a thin metal film onto a substrate, [14,15] which dewets to form catalyst nanoparticles at an elevated temperature prior to growth. [16][17][18] While these catalysts are easily prepared and patterned by shadow masking or lithography, [7,14] these approaches are not easily able to create nanocluster catalysts that have monodisperse diameters and quantifiable areal densities. In thin metal films, both the nanocluster size and areal density are coupled to the film thickness, and the annealing procedure affects the size, density, and the chemical state of the nanoclusters. Recently, Huh et al. [19] demonstrated a route for controlling the density of CNT growth using varying densities of colloidal cobalt nanoparticles; however, due to nanoparticle coalescence their route does not enable precise quantification of nanocluster areal density and leads to a broad distribution of CNT diameters. Zhang et al. [20] also recently demonstrated the control of CNT growth by varying the density of Co-Mo nanoparticles, although their route is unable to independently vary the diameter and the areal density of nanoparticles.We employ a methodology for synthesizing iron oxide nanoclusters that utilizes micelles formed by the amphiphilic block copolymer, polystyrene-b-poly(acrylic acid) (PS-b-PAA). [21,22] This catalyst system has significant value because it enables the creation of nanocluster arrays of a chosen metal species, with independent control of the nanocluster diameter and areal density. [22] In previous work, nanocluster diameters were varied between 5 and 16 nm and the areal density was varied from 6.0 × 10 10 to 1 × 10 9 cm -2 , although variation outside of these ranges is easily accessible. At higher areal densities the nanoclusters are hexagonally ordered. Further, as we have presented separately, the nanocluster arrays can be patterned on the micrometer length scale using microcontact printing.[23]Here, we utilize this system to create arrays of uniform-diameter iron oxide nanoclusters, with quantifiable areal densities that can be varied over more than an order of magnitude. We achieve vertical CNT growth from our catalyst system through appropriate selection of the substrate, catalyst preparation procedure, and reaction conditions. To the best of our knowledge, our work is the first exampl...

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“…The Fe and Mo layers were transformed into nanoparticles which were dispersed on the A1203 rough surface. Our model is similar to these proposed by Zhang et al [9] and Lacerda et al [16]. A1203 underlayer is the most critical for the formation of SWNTs, because it plays the key role of providing the proper stable support for the Fe nanoparticles and prevents the Fe nanoparticles to aggregate.…”

Section: Introductionsupporting

confidence: 61%

On the roles of multilayered metal catalysts in the synthesis of high-quality single-walled carbon nanotubes

Shin²,

Leou³

et al.

2006 IEEE Conference on Emerging Technologies - Nanoelectronics

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In this paper, high quality single-walled carbon nanotubes (SWNTs) were synthesized by multilayered metal catalysts on silicon or silicon oxide substrate using thermal chemical vapor deposition method. The roles of multilayered metal catalyst were investigated by systematically varying the combinations of multilayered structure. Scanning electron microscopy, Atomic force microscopy, Auger electron spectroscopy, and X-ray photoelectron spectroscopy were used to examine the evolution of the morphology and the oxidation state of each constituent of the multilayered structure in the thermal processes and their roles in controlling the formation of SWNTs.

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Thin-film metal catalyst for the production of multi-wall and single-wall carbon nanotubes

Abstract: Articles you may be interested inElectron beam induced deposition of cobalt for use as single-and multiwalled carbon nanotube growth catalyst

Cited by 39 publications

References 28 publications

Low Temperature Synthesis of Single-Walled Carbon Nanotubes in an Inductively Coupled Plasma Chemical Vapor Deposition System

Low Temperature Synthesis of Single-Walled Carbon Nanotubes in an Inductively Coupled Plasma Chemical Vapor Deposition System

Controlling the Morphology of Carbon Nanotube Films by Varying the Areal Density of Catalyst Nanoclusters Using Block‐Copolymer Micellar Thin Films

On the roles of multilayered metal catalysts in the synthesis of high-quality single-walled carbon nanotubes

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