Fabrication of Carbon Nanoparticle Strand under Pulsed Arc Discharge (original) (raw)
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Carbon nanotubes (CNTs) were grown using a DC arc discharge process in an air atmosphere and relevant process parameters were investigated. Without using an inert gas, multi walled carbon nanotubes could be synthesized in the deposit area of the cathode even in an air atmosphere, but single walled carbon nanotubes were not detected in the soot area despite using the same process conditions as in the inert gas. The air pressure for the highest yield of multi walled CNTs was 300 Torr. In addition, the quantity of amorphous carbon and other nanoparticles in the process chamber was remarkably reduced by this technique, showing that an efficient, feasible method of large scale CNT fabrication could be achieved by the arc discharge process.
Characterization of carbon nanotubes produced by arc discharge: Effect of the background pressure
Journal of Applied Physics, 2004
Single walled carbon nanotubes ͑SWNT͒ produced by the anodic arc discharge over a range of constant background pressures of helium ͑100-1000 Torr͒ were examined under a high-resolution transmission electron microscope, and a Raman spectrometer. It was found that the average SWNT diameter is about 2 nm and fairly independent of the background pressure. Analysis of the relative purity of SWNTs samples suggests that highest SWNT relative concentration can be obtained at background pressure of about 200-300 Torr. Measured anode ablation rate increases linearly with background pressure. The model of the anodic arc discharge was developed. It was found that the predicted anode ablation rate agrees well with experiment suggesting that electron temperature in the anodic arc is about 0.5 eV.
Journal of Nanoparticle Research, 2015
Three kinds of carbon nanostructures, i.e., graphene nanoflakes (GNFs), multi walled carbon nanotubes (MWCNTs), and spherical carbon nanoparticles (SCNPs) were comparatively investigated in one run experiment. These carbon nanostructures are located at specific location inside the direct current plasma-assisted arc discharge chamber. These carbon nanomaterials have been successfully synthesized using graphite as arcing electrodes at 400 torr in helium (He) atmosphere. The SCNPs were found in the deposits formed on the cathode holder, in which highly curled graphitic structure are found in majority. The diameter varies from 20 to 60 nm and it also appears that these particles are self-assembled to each other. The MWCNTs with the diameter of 10-30 nm were obtained which were present inside the swelling portion of cathode deposited. These MWCNTs have 14-18 graphitic layers with 3.59 Å interlayer spacing.
Investigation on preparation of multiwalled carbon nanotubes by DC arc discharge under N2 atmosphere
Carbon, 2004
MWCNTs and SWCNT bands were prepared and carbon nanostructures were formed by DC arc discharge under N 2 atmosphere. The effects of nitrogen pressure and flow rate on the yield and morphology of CNTs, and morphology of carbon nanostructures were investigated separately. SEM, HR-TEM, EDX in SEM and TEM, and XRD were performed to characterize the products. It was found that MWCNTs and SWCNTs bands exist in the inner core of the cathode deposit, but the former one is the main product. The suitable N 2 atmosphere should be in the region of 200-300 Torr, and the N 2 flow rate should be smaller than 350 mL/min. The inner diameter and the length of growth of MWCNTs obviously increases with the increase of the N 2 pressure from 0 to 900 Torr, but the change of outside diameter of MWCNTs does not show a good regularity. Both the inner and outside diameters of MWCNTs slightly decrease with the increase of the N 2 flow rate from 0 to 1000 mL/min. Right angle structure of SWCNT band and graphite layers in MWCNT was observed. It is very possible that a little amount of nitrogen atoms has doped into MWCNTs. Several different carbon nanostructures were observed in the products collected from the different parts in the DC arc discharge apparatus.
On the conditions of carbon nanotube growth in the arc discharge
Nanotechnology, 2004
The conditions for single wall carbon nanotube formation in the arc discharge method of nanotube production are described. Carbon nanotube seed formation and charging in the interelectrode gap are found to be very important effects that may alter carbon nanotube formation on the cathode surface. The model predicts that the long carbon nanotubes formed in the relatively dense plasma region can be deposited on the cathode surface. The nanotubes in the cathode deposit are primarily oriented in the cathode surface plane and not along the electric field. This prediction is qualitatively confirmed by an SEM analysis of the cathode deposit.
A comparative study of arc discharge and chemical vapor deposition synthesized carbon nanotubes
Fuel and Energy Abstracts
A comparative study on carbon nanotubes (CNTs) synthesized by arc discharge and chemical vapor deposition (CVD) techniques have been performed to use CNTs as an application for hydrogen storage. Synthesized CNTs have been characterized by using X-ray diffraction (XRD), Raman spectroscopy, FT-IR spectroscopy and Scanning electron microscopy (SEM) measurements. X-ray diffraction confirms the structure and diameter distribution of CNTs. It is observed from Raman spectroscopy that D-band (1345 cm−1) for CNTs synthesized by arc discharge is broad, while CNTs synthesized by CVD it is almost negligible due to nested layers of carbon. The G band (1707 cm−1) in CVD synthesized CNTs is sharp than the CNTs synthesized by arc discharge. FT-IR spectroscopy confirms the stretching of bonds (C▶ In this study we synthesized CNTs by two methods. ▶ MWNTs were obtained by CVD and SWNTs by arc discharge. ▶ Raman spectroscopy confirms the types of CNTs. ▶ Obtained CNTs have been suggested as a good hydrogen storage media.
Diamond and Related Materials, 2007
The effect of discharge current on the synthesis of single-walled carbon nanotubes (SWCNTs) was studied under controlled atmosphere at 500°C by electric arc discharge. It was shown that the production rate of collected soot was increased but the purity of SWCNTs decreased with increasing discharge current. With a current of 100 A, the SWCNT was very uniform in diameter and a high purity rate of 55% was achieved, as shown by TEM and Raman spectra. Then the influence of electric force, discharge current and catalyst distribution on the formation of SWCNTs was also discussed.