Nanoparticle

M A TE RI A L S CH A RACT ER IZ A TI O N 62 ( 20 1 1 ) 6 3 5 6 4 1

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Chemical changes in carbon Nanotube-Nickel/Nickel Oxide philia/ nail nanoparticle heterostructures treated at high temperatures
Nitin Chopraa,?, Hylton G. McWhinney b , Wenwu Shi a
a

Metallurgical and Materials Engineering, decoct for Materials for Information Technology (MINT), Box 870202, The University of Alabama, Tuscaloosa, AL 35487 USA b Prairie View A&M University, TX 77446 USA

AR TIC LE D ATA
Article history: Received 25 January 2011 Received in revised form 10 April 2011 Accepted 15 April 2011 Keywords: Core/shell nanoparticles Carbon carbon nanotubes Heterostructures XPS Electron microscopy

ABSTR ACT
Heterostructures composed of carbon nanotube (CNT) coated with Ni/NiO core/shell nanoparticles (denoted as CNC heterostructures) were synthesized in a wet-chemistry and single-step synthesis route involving direct nucleation of nanoparticles on CNT surface. two different aspects of CNC heterostructures were studied here. First, it was observed that the nanoparticle coatings were more uniform on the as-produced and non-purified CNTs compared to purified (or acid treated) CNTs.



These heterostructures were characterized using electron microscopy, Raman spectroscopy, and energy dispersive spectroscopy. Second, caloric stability of CNC heterostructures was studied by annealing them in N2-rich (O2-lean) purlieu between 125 and 750 °C for 1 h. A flesh out X-ray photoelectron spectroscopy and Raman spectroscopy analysis was performed to evaluate the effectuate of annealing temperatures on chemical composition, phases, and stability of the heterostructures. It was observed that the CNTs show in the heterostructures completely decomposed and core Ni nanoparticle oxidized significantly between 600 and 750 °C. © 2011 Elsevier Inc. All rights reserved.

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Introduction

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