TY  - JOUR
N2  - This study aimed at investigating the effect of the fluidized bed chemical vapor deposition (FBCVD) process parameters on growth mechanism, morphology and purity of the multiwalled carbon nanotubes (MWCNTs). Nanotubes were produced in a vertical FBCVD reactor by catalytic decomposition of ethylene over Al2O3 supported nano-iron catalyst buds at different flow rates. FESEM, TEM, Raman spectroscopy and TGA thermograms were used to elaborate the growth parameters of the as grown MWCNTs. As the growth process was driven by the process temperatures well below the iron-carbon eutectic temperature (1147 °C), the appearance of graphite platelets from the crystallographic faces of the catalyst particles suggested a solid form of the catalyst during CNT nucleation. A vapor-solid-solid (VSS) growth mechanism was predicted for nucleation of MWCNTs with very low activation energy. The nanotubes grown at optimized temperature and ethylene flow rate posed high graphitic symmetry, purity, narrow diameter distribution and shorter inter-layer spacing. In Raman and TGA analyses, small ID/IG ratio and residual mass revealed negligible ratios of structural defects and amorphous carbon in the product. However, several structural defects and impurity elements were spotted in the nanotubes grown under unoptimized process parameters. © 2016 Elsevier B.V.
ID  - scholars6982
KW  - Activation energy; Amorphous carbon; Carbon nanotubes; Catalysts; Chemical analysis; Chemical vapor deposition; Crystal growth; Crystal impurities; Defects; Deposition; Electron microscopy; Ethylene; Fluidized bed process; Fluidized beds; Nanostructures; Nanotubes; Nucleation; Thermogravimetric analysis; Vapor deposition; Yarn
KW  -  Catalytic decomposition; Chemical vapor depositions (CVD); Diameter distributions; Fluidized bed chemical vapor deposition; Iron carbon eutectic temperature; Low-activation energy; Multiwalled carbon nanotube (MWCNTs); Process temperature
KW  -  Multiwalled carbon nanotubes (MWCN)
A1  - Shukrullah, S.
A1  - Mohamed, N.M.
A1  - Shaharun, M.S.
A1  - Naz, M.Y.
JF  - Materials Chemistry and Physics
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978322453&doi=10.1016%2fj.matchemphys.2016.03.013&partnerID=40&md5=d074c68a399f364fba4caa4e21d651e1
VL  - 176
Y1  - 2016///
N1  - cited By 24
TI  - Parametric study on vapor-solid-solid growth mechanism of multiwalled carbon nanotubes
SP  - 32
AV  - none
EP  - 43
PB  - Elsevier Ltd
SN  - 02540584
ER  -