authors |
Silva, RM; Fernandes, AJS; Ferro, MC; Pinna, N; Silva, RF |
nationality |
International |
journal |
APPLIED SURFACE SCIENCE |
author keywords |
Nitrogen doping; Carbon nanotubes; Chemical vapor deposition |
keywords |
CARBON NANOTUBE ARRAYS; NITROGEN; OPTIMIZATION; SPECTROSCOPY; STORAGE |
abstract |
The Taguchi method with a parameter design L-9 orthogonal array was implemented for optimizing the nitrogen incorporation in the structure of vertically aligned N-doped CNTs grown by thermal chemical deposition (TCVD). The maximization of the I-D/I-G ratio of the Raman spectra was selected as the target value. As a result, the optimal deposition configuration was NH3 = 90 sccm, growth temperature = 825 degrees C and catalyst pretreatment time of 2 min, the first parameter having the main effect on nitrogen incorporation. A confirmation experiment with these values was performed, ratifying the predicted I-D/I-G ratio of 1.42. Scanning electron microscopy (SEM) characterization revealed a uniform completely vertically aligned array of multiwalled CNTs which individually exhibit a bamboo-like structure, consisting of periodically curved graphitic layers, as depicted by high resolution transmission electron microscopy (HRTEM). The X-ray photoelectron spectroscopy (XPS) results indicated a 2.00 at.% of N incorporation in the CNTs in pyridine-like and graphite-like, as the predominant species. (C) 2015 Elsevier B.V. All rights reserved. |
publisher |
ELSEVIER SCIENCE BV |
issn |
0169-4332 |
year published |
2015 |
volume |
344 |
beginning page |
57 |
ending page |
64 |
digital object identifier (doi) |
10.1016/j.apsusc.2015.03.073 |
web of science category |
Chemistry, Physical; Materials Science, Coatings & Films; Physics, Applied; Physics, Condensed Matter |
subject category |
Chemistry; Materials Science; Physics |
unique article identifier |
WOS:000353802600009
|