Lupu, D., Biris, A. R., Baltog, I., Baibarac, M., Kuncser, V., Schinteie, G., Valeanu, M., Lefrant, S., Biris, A. S., Misan, I. & Filoti, G. (2009) Carbon nanotubes from ethanol on Fe-Co/MgO catalysts and related interface phenomena. J. Optoelectron. Adv. Mater. 11 338–347.
Added by: Laurent Cournède (2016-03-10 21:41:24) |
Type de référence: Article Numéro d'identification (ISBN etc.): 1454-4164 Clé BibTeX: Lupu2009 Voir tous les détails bibliographiques |
Catégories: PMN Mots-clés: alcohol, carbon nanotubes, ccvd, chemical-vapor-deposition, diameter distribution, Fe-Co/MgO catalyst, growth, hydrogen, iron particles, mechanism, mgo, Mossbauer spectroscopy, purity Créateurs: Baibarac, Baltog, Biris, Biris, Filoti, Kuncser, Lefrant, Lupu, Misan, Schinteie, Valeanu Collection: J. Optoelectron. Adv. Mater. |
Consultations : 1/454
Indice de consultation : 3% Indice de popularité : 0.75% |
Résumé |
Mossbauer spectroscopy studies of Fe-Co/MgO catalysts proved that a high dispersion degree of Fe may be achieved for catalysts containing Fe/Co in a ratio close to 1. During materials processing. the presence of hydrogen at high temperatures, even for short time, induced an increased particle size of the catalytic Fe. The evaluation of various iron species from their areas in the Mossbauer spectra revealed the dependence of the nanotube amount on (FeCo alloy + Fe(2+)) content in the catalyst, in good agreement with literature mechanisms. The Raman spectra show that carbon nanotubes synthesized from ethanol in argon flow on 4.5\%Fe:4.5\%Co/MgO are richer in low diameter (0.7-1.0nm) tubes than those obtained at low ethanol pressure, in agreement with the effects of hydrogen reported in literature. The close similarity with the Raman spectra of Aldrich double-walled carbon nanotubes and from literature, recommends the syntheses in argon flow as better conditions for double-walled carbon nanotube growth.
Added by: Laurent Cournède |