TY  - JOUR
SP  - 129
TI  - Optimum temperature on structural growth of multiwalled carbon nanotubes with low activation energy
N1  - cited By 21
AV  - none
EP  - 138
SN  - 09259635
PB  - Elsevier Ltd
KW  - Carbon; Carbon nanotubes; Catalyst activity; Catalysts; Chemical activation; Ethylene; Graphic methods; Growth temperature; Multiwalled carbon nanotubes (MWCN); Statistical mechanics; Statistical methods; Structural optimization; Yarn
KW  -  Approximate analysis; Catalytic decomposition; Coefficient of variation; Descriptive statistics; Diameter distributions; Low-activation energy; Optimum growth temperature; Structural defect
KW  -  Activation energy
ID  - scholars5825
N2  - Abstract This study deals with the catalytic decomposition of ethylene over Fe2O3/Al2O3 catalyst for the nucleation of nanotubes at growth temperature of 700 to 950 °C. The motivation for conducting this work was primarily an interest in growing a better yield of well-structured MWCNTs by making use of the minimum activation energy. A vertically fluidize bed reactor was used to accomplish the experimental work on production of nanotubes. The final product was characterized using a set of imaging, spectroscopic and statistical tools. The required activation energy of the reaction was reduced down to 19.5 kJ/mol. This decrease in activation energy was attributed to Al2O3 promoter and high density of the active sites on the surface of the chemically activated catalyst. Descriptive statistics on the tube diameter distribution revealed the formation of positively skewed histograms at 700 to 800 °C, negatively skewed histograms at 850 to 900 °C and symmetrically skewed histogram at 950 °C. The highest coefficient of variation of 14.5 was calculated in diameter distribution of CNTs grown at 950 °C. A narrow diameter distribution with ideally graphitized tube structures was predicted at the optimum growth temperature of 800 °C. ID/IG and IG'/IG ratios and the product weight loss calculated from the Raman spectra and approximate analyses, respectively, confirmed the growth of 94 pure MWCNTs. © 2015 Elsevier B.V.
VL  - 58
UR  - https://www.scopus.com/inward/record.uri?eid=2-s2.0-84938086762&doi=10.1016%2fj.diamond.2015.07.005&partnerID=40&md5=3aa3d762e0c639e1212e4b5294196bf4
A1  - Shukrullah, S.
A1  - Mohamed, N.M.
A1  - Shaharun, M.S.
JF  - Diamond and Related Materials
Y1  - 2015///
ER  -