Influence of Melting of Transition Metal Oxides on the Morphology of Carbon Nanostructures

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Different types of carbon nanostructure materials have been grown on nano-sized transition metal oxide based catalyst particles by catalytic chemical vapour deposition. The present investigation reveals an important role of melting or surface melting of oxide catalysts for the growth of carbon nanostructure materials. In the reducing environment prevailing during the growth of nanostructures, oxide catalysts are reduced to metals, which may act as a template for the growth of carbon nanostructure materials. Flow rate of acetylene gas is crucial in catalyzing the growth, as high flow rate of acetylene may cover the catalyst particles with a layer of decomposed carbon, rendering the particles incapable of playing the role of catalyst. The size of the catalyst and the extent of melting, determined primarily by the extent of doping, are important in deciding whether the conditions are favourable for the growth of multi walled carbon nanotube, nanofiber or other nanostructures. Smaller particle size and low doping level favour the growth of multi walled carbon nanotube while growth of nanofiber is commonly observed with larger particles and higher doping level. The size (i.e. diameter) of the nanostructures growing around the catalyst is proportional to the particle size of the catalyst.

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Edited by:

B.S.S. Daniel and G.P. Chaudhari

Pages:

159-163

Citation:

M. Jana et al., "Influence of Melting of Transition Metal Oxides on the Morphology of Carbon Nanostructures", Advanced Materials Research, Vol. 585, pp. 159-163, 2012

Online since:

November 2012

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$38.00

[1] A.C. Dupuis, The catalyst in the CCVD of carbon nanotubes-a review, Prog. Mater. Sc. 50 (2005) 929-961.

[2] M. Jana, A. Sil, S. Ray, Tailoring of surface melting of oxide based catalyst particles by doping to influence the growth of multi-walled carbon nano-structures, Carbon, 49 (2011) 5142-5149.

DOI: https://doi.org/10.1016/j.carbon.2011.07.031

[3] L. Ni, K. Kuroda, L-P. Zhou, K. Ohta, K. Matsuishi, J. Nakamura, Decomposition of metal carbides as an elementary step of carbon nanotube synthesis, Carbon, 47 (2009) 3054-3062.

DOI: https://doi.org/10.1016/j.carbon.2009.07.009

[4] H. Cui, G. Eres, J.Y. Howe, A. Puretkzy, M. Varela, D.B. Geohegan, D.H. Lowndesa, Growth behavior of carbon nanotubes on multilayered metal catalyst film in chemical vapor deposition, Chem. Phys. Lett. 374 (2003) 222-228.

DOI: https://doi.org/10.1016/s0009-2614(03)00701-2

[5] Z.L. Wang, J.M. Petroski, T.C. Green, M.A. El-Sayed, Shape transformation and surface Melting of cubic and tetrahedral platinum nanocrystals, J. Phys. Chem. B, 102 (1998) 6145-6151.

DOI: https://doi.org/10.1021/jp981594j

[6] K.F. Peters, Y-W. Chung, J.B. Cohen, Surface melting on small particles, Appl. Phys. Lett. 71 (1997) 2391-2393.