Structural reorganization of carbon nanoparticles into single-wall nanotubes

Larciprete, R.; Lizzit, Silvano; Botti, S.; Cepek, Cinzia; Goldoni, Andrea

doi:10.1103/physrevb.66.121402

Cited by 33 publications

(32 citation statements)

References 21 publications

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“…We interpret the C 1s line at 285.4 eV for Fe, 285.3 eV for Fe oxide, and 285.55 eV for Ni as being due to disordered C with partially increased sp 3 hybridization and possibly being hydrogenated. Such defect lines are often observed for CNTs, 44 graphite powder, 46 and nanocarbon samples. 44 We note that our previous C 1s data 4 for in situ deposited Fe exposed to ∼2 × 10 -7 mbar C 2 H 2 background pressure initially showed a peak at 282.6 eV, which we attributed to chemisorbed carbon, and then a carbide peak at 283.2 eV.…”

Section: +mentioning

confidence: 82%

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State of Transition Metal Catalysts During Carbon Nanotube Growth

et al. 2009

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We study catalyst-support and catalyst-carbon interactions during the chemical vapor deposition of singlewalled carbon nanotubes by combining environmental transmission microscopy and in situ, time-resolved X-ray photoelectron spectroscopy. We present direct evidence of what constitutes catalyst functionality by comparing the behavior of Ni, Fe, Pd, and Au model catalyst films on SiO 2 during preannealing in O 2 and NH 3 and during C 2 H 2 decomposition. The catalyst metal surface supplies sites to dissociate the hydrocarbon precursor and then guides the formation of a carbon lattice and the liftoff of a carbon cap. The catalysts are sharply distinguished by their reactivity toward activation of the hydrocarbon precursor, following trends known from heterogeneous catalysis. For Fe and Ni, the active state of the catalyst is a crystalline metallic nanoparticle. Graphitic networks do not form on oxidized Fe. Pd forms a silicide on SiO 2 under our reducing conditions. Pd (silicides) and Au nanocrystals are catalytically less efficient in terms of precursor dissociation, while the low adhesion of C on Au surfaces impedes nanotube nucleation.

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Section: +mentioning

confidence: 82%

“…43, 44 We assign the initial C 1s signatures to more disordered C-C bonding. 45 The later appearance of a C 1s CNT signature for Fe may be due to an initial screening by disordered carbon.…”

Section: +mentioning

confidence: 99%

State of Transition Metal Catalysts During Carbon Nanotube Growth

et al. 2009

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“…Previous photoemission and x-ray absorption studies of CNTs have been performed mainly on either aligned or randomly oriented multiwalled nanotubes, or on randomly oriented SWNT films. [3][4][5][6][7] In most of these, the electronic structure of the nanotubes was found to be largely similar to that of graphite. Valence band spectral features common to both graphite and nanotubes are easily identified, but are significantly broader for the nanotube spectra.…”

Section: Introductionmentioning

confidence: 92%

“…In x-ray absorption spectra, chemical vapor deposition ͑CVD͒-grown multiwalled nanotubes have broader * a͒ Electronic mail: lbflemin@unity.ncsu.edu and * peaks than graphite as a result of defects, while SWNTs show a stronger similarity. 6,7 There are some difficulties associated with measuring the electronic structure of bulk CNT samples. Multiwalled nanotubes are comprised of concentric shells, with the total density of states ͑DOS͒ approximately representing a sum over the DOS of the layers.…”

Section: Introductionmentioning

confidence: 99%

Near-edge absorption fine structure and UV photoemission spectroscopy studies of aligned single-walled carbon nanotubes on Si(100) substrates

Fleming

Ulrich

Efimenko

et al. 2004

Journal of Vacuum Science &Amp; Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena

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Articles you may be interested inCharacterization of molecular nitrogen in III-V compound semiconductors by near-edge x-ray absorption fine structure and photoemission spectroscopies J. Vac. Sci. Technol. A 26, 592 (2008); 10.1116/1.2929851 Core-level photoemission and near-edge x-ray absorption fine-structure studies of GaN surface under lowenergy ion bombardment J. Appl. Phys. 95, 5487 (2004); 10.1063/1.1707232Ultrafast carrier dynamics in single-walled carbon nanotubes probed by femtosecond spectroscopy Pendant group orientation of poly(2-vinylnaphthalene) thin film surface studied by near-edge x-ray absorption fine structure spectroscopy (NEXAFS) and angle-resolved ultraviolet photoelectron spectroscopy (ARUPS)

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“…Botti et al (2002) report a dense array of CNTs grown on silicon by spraying amorphous hydrogenated carbon nanoparticles on a Si substrate. Other similar approaches have been reported in the literature (Koshio et al, 2002;Larciprete et al, 2002;. Figure 1 shows transmission electron microscope images of carbon nanostructures deposited on a carbon implanted Ge nanoparticle sample.…”

Section: Catalyst Free Synthesis Of Cntsmentioning

confidence: 81%