Why metals such as Ni, Fe, Co, Cr acts as a catalyst during growth of CNT using CVD method? What is the mechanism behind the growth of CNT over these catalyst? Is there any possibility to use any other more efficient catalyst for better and easy growth?
Hi Uday,
Follow the below link, you will get your answer.
in brief,
Most commonly-used metals are Fe, Co, Ni, because of two main reasons: (i) high solubility of carbon in these metals at high temperatures; and (ii) high carbon diffusion rate in these metals. Besides that, high melting point and low equilibriumvapor pressure of these metals offer a wide temperature window of CVD for a wide range of carbon precursors. Recent considerations are that Fe, Co, and Ni have stronger adhesion
with the growing CNTs (than other transition metals do) and hence they are more fficient in forming high-curvature (low diameter) CNTs such as SWCNTs (Ding et al., 2008).
http://cdn.intechopen.com/pdfs-wm/16802.pdf
@sujoy sarkar: Thank you very much sir. According to you, in what different direction we can make an attempt to find more efficient catalyst for CNT growth? Or what are the other aspects as far as these metals are concerned are yet to be resolved? Lot of works have been done in this and I want to handle some new problem. Kindly give your suggestion.
The mentiond catalysts may also be suitable for low diameters as well as multiplewalled CNTs. More efficient catalysts for CNT growth may be of the same material as above mentioned, but simply smaller nanoparticles. Also very efficient are alloys, will send reference :) Hope this helps :)
@Per Arvid Löthman : Thank you very much sir. It will be helpful if you can give me some reference. It will be great if you can guide me into some newer aspect of this growth mechanism. Is it possible to try some different route which can make things better or easier. Kindly let me know.
...there are also anp0ther way of making CNTs....without catalysts at all! Or rather - with nanoparticles that are believed to be intert. Just scratch the wafer surface with a diamond tip and leave the residues i.e. the posder and try to grow CNTs. Silica as well as alumina "scratched" nanoparticles have shown catalytical activity, and there is much more research to be done ther in order to optimize and evaluate the outcome.
@Per Arvid Löthman: Thank you very much sir. It will be very helpful if you can give me some source of publications supporting these concepts. It will be helpful for me in understanding the concepts in more detailed manner.
Dear Udaya,
This address is the best for you in order to know about the answer of your question:
Carbon Nanotube Synthesis and Growth Mechanism
by
Mukul Kumar
Department of Materials Science & Engineering
Meijo University, Nagoya 468-8502
Japan
Good Luck
http://www.intechopen.com/download/pdf/16802
- Badges
- Science topic
- Similar topics
- Engineering
- Chemical Engineering