Purification of single-walled carbon nanotubes synthesized by the catalytic decomposition of hydrocarbons

Li, F.; Cheng, Hui‐Ming; Xing, Yajuan; Tan, Ping‐Heng; Su, Ge

doi:10.1016/s0008-6223(00)00061-0

Cited by 69 publications

(25 citation statements)

References 9 publications

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“…[50][51][52] Among the abundant purification methods, refluxing in a concentrated acid was considered for the removal of impurities from MWCNTs with little destruction of tube walls. 53 SEM images of raw MWCNTs-Raw-10 and MWCNTs-O-10 samples are shown in Fig.…”

Section: Deposition and Decomposition Of The Cobalt Precursor On Carbmentioning

confidence: 99%

The nature of cobalt species in carbon nanotubes and their catalytic performance in Fischer–Tropsch reaction

et al. 2009

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The nature of cobalt species in the catalysts supported by multi-wall carbon nanotubes and their catalytic performance in Fischer-Tropsch synthesis were investigated using nitrogen adsorption, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, high resolution transmission electron microscopy, in situ magnetic method, X-ray absorption and temperature programmed reduction. The catalysts were prepared by incipient wetness impregnation using solutions of cobalt nitrate assisted by sonochemical process followed by calcination in nitrogen. The characterization techniques uncovered that acid pretreatment oxidized the carbon nanotube surface and removed impurities. Small cobalt oxide particles of 8-10 nm diameter and irregular shape anchored to the outer surface of carbon nanotubes were detected in the calcined samples by several characterization techniques. The catalysts displayed high cobalt reducibility, which was slightly affected by the pretreatment with nitric acid and nanotube outer diameter. Cobalt catalysts supported on carbon nanotubes exhibited high catalytic activity in Fischer-Tropsch synthesis. Pretreatment with nitric acid leads to a 25% increase in hydrocarbon yield, while carbon nanotube diameter does not seem to significantly affect the Fischer-Tropsch performance of the resulting catalysts.

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Section: Deposition and Decomposition Of The Cobalt Precursor On Carbmentioning

confidence: 99%

The nature of cobalt species in carbon nanotubes and their catalytic performance in Fischer–Tropsch reaction

et al. 2009

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“…The MWNT samples were obtained at 800 • C for 1 h. The pressure was maintained under 0.032 Torr for the whole process. The as-grown MWNT samples were purified by soaking in benzene solution for 24 h to eliminate carbonaceous impurities, and then treating by ultrasound for 1 h in 37 wt% HCl followed by the acid dissolution of catalyst particles for 6 h under stirring [44]. One commercial MWNT sample (Conyuan Biochemical Technology, Taiwan) was also obtained for comparison.…”

Section: Synthesis Of Mwntsmentioning

confidence: 99%

Adsorption equilibrium of sulfur hexafluoride on multi-walled carbon nanotubes

Chiang

2010

Journal of Hazardous Materials

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“…There has also been impressive progress in purifying as-produced material to remove unwanted catalyst particles and amorphous carbon material. [3][4][5][6][7][8][9] With the increasing availability of relatively pure product, it is becoming feasible to pursue geometry-selective separations of carbon nanotubes.…”

Section: Introductionmentioning

confidence: 99%

Capillary Electrophoresis Separations of Bundled and Individual Carbon Nanotubes

et al. 2003

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Capillary electrophoresis (CE) has been performed on polymer-stabilized bundles and sodium dodecyl sulfate (SDS) suspensions of high-pressure carbon monoxide (HiPco)-produced single-walled carbon nanotubes. Realtime Raman spectroscopy has been used for detection and characterization of the separation process. Radialbreathing-mode vibrational frequencies are sensitive to nanotube diameter. Monitoring of these modes demonstrates the separation of poly(vinylpyrrolidone) (PVP)-stabilized tubes into fractions of differing bundle composition. Separations on SDS suspensions indicate that CE is capable of separating bundled nanotubes from isolated individuals on the basis of differences in nanotube mobility, depending on changes in diameter or bundle size.

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Purification of single-walled carbon nanotubes synthesized by the catalytic decomposition of hydrocarbons

Cited by 69 publications

References 9 publications

The nature of cobalt species in carbon nanotubes and their catalytic performance in Fischer–Tropsch reaction

The nature of cobalt species in carbon nanotubes and their catalytic performance in Fischer–Tropsch reaction

Adsorption equilibrium of sulfur hexafluoride on multi-walled carbon nanotubes

Capillary Electrophoresis Separations of Bundled and Individual Carbon Nanotubes

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