TOWARDS THE OPTIMIZATION OF CARBON NANOTUBE PROPERTIES VIA IN SITU AND EX SITU STUDIES OF THE GROWTH MECHANISM
D. V. Krasnikov1,2, A. N. Shmakov1,2,3, V. L. Kuznetsov1,2, A. V. Ishchenko1,2
1Boreskov Institute of Catalysis SB RAS, Novosibirsk, Russia
2Novosibirsk State University, Novosibirsk, Russia
3Budker Institute of Nuclear Physics SB RAS, Novosibirsk, Russia
Keywords: углеродные нанотрубки, in situ методы исследования, катализ, синхротронное излучение, дифракция, carbon nanotubes, in situ techniques, catalysis, synchrotron radiation, X-ray diffraction
Abstract
The synthesis conditions of multi-walled carbon nanotubes (MWCNTs) indirectly determine their application potential through the decisive role in the characteristics of individual tubes: diameter distribution, structure and defectiveness of graphene walls, the amount of metal impurities and amorphous carbon. In the present work, we have studied the influence of the catalyst composition and synthesis conditions on the diameter distribution and the structure of nanotube walls. We have observed the influence of the particle size for MWCNT synthesis ( i.e. size effect) on catalytic activity by ex situ and in situ techniques: in situ X-ray diffraction on synchrotron radiation (SRXRD), gas chromatography, and ex situ transmission electron microscopy. The data obtained by in situ SRXRD are in agreement with the results collected using laboratory tubular fix-bed catalytic reactor allowing thereby extending the applicability of the approach. For the first time we have shown the increase of the fraction of graphene walls in the total MWCNT diameter with time.
|
