XPS and Raman characterization of single-walled carbon nanotubes grown from pretreated Fe2O3 nanoparticles

Placidus B. Amama, Birck Nanotechnology Center, Purdue University
Dmitry Zemlyanov, Birck Nanotechnology Center, Purdue University
B Sundarakannan, Department of Physics and Institute for Functional Materials, University of Puerto Rico
Ram S. Katiyar, School of Mechanical Engineering, Purdue University
Timothy Fisher, Birck Nanotechnology Center, Purdue University

Date of this Version

July 2008

Citation

J. Phys. D: Appl. Phys. 41 (2008) 165306 (5pp)

This document has been peer-reviewed.

 

Abstract

X-ray photoelectron (XPS) and Raman spectroscopic techniques have been used to study the influence of the annealing ambient (N2, Ar and H2) of nearly monodispersed Fe2O3 nanoparticles (mean size = 3.2 ± 1 nm) on the growth of carbon nanotubes by microwave plasma chemical vapour deposition. XPS characterization of the catalytic templates reveals that a N2 ambient reduces sintering of the Fe2O3 nanoparticles and confirms that the chemical phase involved in the nucleation of nanotubes is the metal state Fe0. Multi-excitation wavelength Raman spectroscopy (514, 574, 633 and 785 nm) reveals that the single-walled carbon nanotubes (SWCNTs) grown from N2-annealed catalyst nanoparticles range between 0.8 and 1.1 nm while SWCNTs grown from Ar-annealed catalyst nanoparticles exhibit a broader diameter distribution in the range 0.8–1.8 nm. The narrowness in the distribution of SWCNTs grown from the N2-annealed catalysts has been attributed to the enhanced stability of Fe2O3 nanoparticles in an N2 ambient.

 

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