Growth of Multi Walled CNX Nanotubes: The Role of Synthesis Methods

Abstract

Multi walled nitrogen doped nanotubes were synthesized using two different methods. The growth mechanism and nitrogen concentration of the nanotubes synthesized by both methods are discussed and studied. The morphology and nitrogen concentration of the nanotubes are seen to strongly depend on the synthesis methods. The results are based on detailed high resolution transmission electron microscopy (HRTEM) data coupled with electron energy loss spectroscopy (EELS).

Influence of Nitrogen Doping on Oxygen Reduction Electrocatalysis at Carbon Nanofiber Electrodes

“…The integrated signal intensity for nitrogen atoms for N-doped CNFs give a surface concentration of 4.0 at. %, consistent with that of Glerup for N-doped CNFs produced by a similar method. Several groups investigating nitrogen-doped graphitic carbons have proposed that the bands at 398 and 401 eV correspond to “pyridinic” and “pyrrolic” nitrogen incorporation, respectively. , The weak band near 405 eV may be attributable to nitrogen atoms substituted in the interior rather than periphery of the graphene sheets .…”

Nitrogen Configuration in Individual CNx-SWNTs Synthesized by Laser Vaporization Technique

“…17 Pyridinic N is generally considered to favor corrugation or buckling of the nanotube walls, leading to characteristic bamboo-shaped MWNTs. 11,15,18 The present CN x -SWNT look as straight as their pure carbon counterparts, which argues for the existence of a local structure preserving the graphitic network.…”

“…Different compound structures can be considered, such as nitrogen vacancies N x V y complexes , or C x N y V z structures such as the hypothetic graphitic C 3 N 4 structure involving pyridinic N atoms . Pyridinic N is generally considered to favor corrugation or buckling of the nanotube walls, leading to characteristic bamboo-shaped MWNTs. ,, The present CN x -SWNT look as straight as their pure carbon counterparts, which argues for the existence of a local structure preserving the graphitic network.…”

Effect of the Synthesis Method on the Distribution of C, B, and N Elements in Multiwall Nanotubes: A Spatially Resolved Electron Energy Loss Spectroscopy Study

“…30 route has been proven to be effective in the synthesis of highly doped CN x MWNTs. 31 The method consists of spraying liquid droplets of a mixture of metallic catalysts and liquid precursors in a furnace at 950 °C. The metal catalyst ([Fe(III)(acetylacetonate) 3 ]) is dissolved in a mixture of acetonitrile (CH 3 CN) and borane-pyridine complex (C 5 H 8 BN), which together both serve as a solvent for the aerosol and also as a source of carbon, nitrogen, and boron.…”

“…They exhibit a bamboolike structure with a very frequent and regular compartmentalized morphology which is typical of carbon nanotubes containing nitrogen. 31,40 The compartmentalization of the nanotubes is caused by caps closing nanotubes of 2-10 hexagonal planes across the inner core of the tubes. A statistical analysis carried out over 50 nanotubes In contrast to the samples produced by synthesis process 1, structural characterization by HRTEM of the samples synthesized by laser vaporization shows that, for this method, byproduct makes up a dominant fraction within the samples.…”