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Journal of Nanomaterials
Volume 2011 (2011), Article ID 736219, 7 pages
Research Article

Gas-Phase Growth of Heterostructures of Carbon Nanotubes and Bimetallic Nanowires

Department of Nanosystem and Nanoprocess Engineering, College of Nanoscience and Nanotechnology, Pusan National University, 30 Jangjeon-Dong, Geumjung-Gu, Busan 609-735, Republic of Korea

Received 22 November 2010; Accepted 4 January 2011

Academic Editor: Theodorian Borca-Tasciuc

Copyright © 2011 Whi Dong Kim et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A simple, inexpensive, and viable method for growing multiple heterostructured carbon nanotubes (CNTs) over the entire surface of Ni-Al bimetallic nanowires (NWs) in the gas phase was developed. Polymer-templated bimetallic nitrate NWs were produced by electrospinning in the first step, and subsequent calcination resulted in the formation of bimetallic oxide NWs by thermal decomposition. In the second step, free-floating bimetallic NWs were produced by spray pyrolysis in an environment containing hydrogen gas as a reducing gas. These NWs were continuously introduced into a thermal CVD reactor in order to grow CNTs in the gas phase. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectrometry analyses revealed that the catalytic Ni sites exposed in the non-catalytic Al matrix over the entire surface of the bimetallic NWs were seeded to radially grow highly graphitized CNTs, which resembled “foxtail” structures. The grown CNTs were found to have a relatively uniform diameter of approximately  nm and 10 to 15 walls with a hollow core. The average length of the gas-phase-grown CNTs can be controlled between 100 and 1000 nm by adjusting the residence time of the free-floating bimetallic NWs in the thermal CVD reactor.