Nitric acid oxidation of vapor grown carbon nanofibers

Lakshminarayanan, Priya V.; Toghiani, Hossein; Pittman, Charles U.

doi:10.1016/j.carbon.2004.04.040

Cited by 292 publications

(182 citation statements)

References 25 publications

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“…catalysis and a standard definition should be unambiguous on this. For example, carbon materials from Pyrograf Products that are known to be vapor-grown carbon nanofibers (VGCNFs) [35,[58][59][60][61] are also sometimes referred to as multiwall carbon nanotubes in the literature due to their quasi-parallel outer walls and large internal channel [62][63][64][65]. In order to avoid any ambiguity in the present work, and in the literature in general, we suggest to generalize the definition used by Dresselhaus and Endo [57].…”

Section: Cnt and Cnf Definitionsmentioning

confidence: 99%

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Analysis of the structure and chemical properties of some commercial carbon nanostructures

Tessonnier

Rosenthal

Hansen

et al. 2009

Carbon

316

256

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For many years the scientific community has believed in a promising future for carbon nanotubes for various applications in such diverse fields as polymer reinforcement, adsorption, catalysis, electronics and medicine. Industrial production of carbon nanotubes and -fibers and the subsequent availability and decrease of price, have rendered this vision feasible. In the last years, several carbon nanomaterial products have been marketed by major chemical companies. In this work, we present an extensive characterization of a representative set of commercially available carbon nanomaterials. Special focus has been put on their quality, i.e. presence of metal or carbonaceous impurities but also homogeneity and structural integrity. The observations are of importance for subsequent use in catalysis where the presence of impurities or defects in the nanostructure can dramatically modify the activity of the catalytic material..

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Section: Cnt and Cnf Definitionsmentioning

confidence: 99%

“…Details about Pyrograf products, Baytubes and NC 3100 synthesis can be found in previous reports and patents [35,[58][59][60][61][66][67][68][69][70]. Briefly, Pyrograf VGCNFs are synthesized by feeding a mixture of CH 4 , NH 3 , Air, H 2 S, Fe(CO) 5 in a horizontal reactor maintained at 1100°C.…”

Section: Synthesis Of the Studied Carbon Nanostructuresmentioning

confidence: 99%

Analysis of the structure and chemical properties of some commercial carbon nanostructures

Tessonnier

Rosenthal

Hansen

et al. 2009

Carbon

316

256

View full text Add to dashboard Cite

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“…These authors indicate that various functional groups can be introduced to the tubes surfaces when the SWNTs are treated with different oxidizing agents. Dilute nitric acid has shown to generate carboxylic acid groups on defect sites already present within nanotubes, whereas a mixture of concentrated sulfuric and nitric acids generates carboxylic acid groups on newly created defective sites [23,24]. Potassium permanganate introduces different amounts of hydroxyl, carbonyl and carboxylic groups within the nanotubes surface [35].…”

Section: Introductionmentioning

confidence: 99%

An efficient method for the carboxylation of few-wall carbon nanotubes with little damage to their sidewalls

Martín

Gutiérrez

Maroto-Valiente

et al. 2013

Materials Chemistry and Physics

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“…Thermogravimetric studies indicate that the shell of VGCFs is less ordered compared to the core. The shell is grown by pyrolysis of carbon, whereas the core originates from catalytic growth [13,14]. Although the growth of VGCFs has been intensively studied, little is known about the bulk and surface structure of the presumably disordered shell of the VGCFs.…”

Section: Introductionmentioning

confidence: 99%

Iron impregnation on the amorphous shell of vapor grown carbon fibers and the catalytic growth of secondary nanofibers

Xia

Bitter

et al. 2009

Diamond and Related Materials

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Vapor grown carbon fibers (VGCFs) with diameters of several microns were synthesized and investigated by high resolution transmission electron microscopy. It was found that the shell of the VGCFs consisted of densely-packed domains embedded in loosely-packed matrix, and both were highly amorphous. Regular edge planes as observed on the surface of fishbone nanofibers do not exist on VGCFs. Hence, surface treatment is more important for the deposition of catalysts. Ammonium ferric citrate (AFC) was employed for the impregnation of iron, where the high viscosity of the aqueous solution of AFC is beneficial. Calcination was found to be a key step to improve the dispersion of the iron particles, which can be attributed to enhanced interactions between iron and carbon due to the gasification of carbon occurring at the iron-carbon interface. Quantitative analysis by X-ray photoelectron spectroscopy showed that the calcination of the supported AFC led to a higher atomic concentration of iron on the surface, indicating smaller particle size and higher dispersion. Secondary carbon nanofibers were grown subsequently on the VGCFs from cyclohexane. The specific surface area was enhanced considerably, from less than 1 m 2 g -1 to 106 m 2 g -1 after the growth of the secondary nanofibers. The obtained composites are promising materials as structured support in heterogeneous catalysis.

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Nitric acid oxidation of vapor grown carbon nanofibers

Cited by 292 publications

References 25 publications

Analysis of the structure and chemical properties of some commercial carbon nanostructures

Analysis of the structure and chemical properties of some commercial carbon nanostructures

An efficient method for the carboxylation of few-wall carbon nanotubes with little damage to their sidewalls

Iron impregnation on the amorphous shell of vapor grown carbon fibers and the catalytic growth of secondary nanofibers

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