Oxidation Kinetics of Nickel Solar Absorber Nanoparticles
(2001) Oxidation Kinetics of Nickel Solar Absorber Nanoparticles. Journal of Physics D: Applied Physics 34(3):pp. 400-406.
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Abstract
The alumina matrix of an electrolytically deposited solar absorber coating was etched away leaving nickel nanorods standing on an aluminium support. The oxidation kinetics of the nickel nanorods, with an approximate diameter of 30 nm and a height of approximately 300 nm, was determined by Infrared (IR) spectroscopy. The IR absorption by longitudinal optical (LO) phonons in NiO was measured before and after exposure to pure oxygen at 260, 280, 300, 320 and 350∞C for different times. The absorptance peak height was determined and used as a measure of the degree of oxidation. The five different isotherms showed power law behaviour with an exponent varying between 0.52 and 0.69. A fit to the homogeneous linear diffusion equation, derived for spherical geometry, gave parabolic rate constants, which are in agreement with data for larger nickel particles and bulk nickel. The deviations in the exponent from that of the parabolic law are discussed in terms of particle geometry and particle agglomeration. The apparent activation energy was determined by the use of a master plot technique to be 1.73 eV.
| Item Type: | Journal Article |
|---|---|
| Status: | Published |
| Subjects: | 240000 Physical Sciences > 240200 Theoretical and Condensed Matter Physics > 240202 Condensed Matter Physics - Structural Properties 290000 Engineering and Technology > 291400 Materials Engineering > 291499 Materials Engineering not elsewhere classified |
| ID Code: | 7675 |
| Deposited By: | Tesfamichael, Tuquabo |
| Deposited On: | 25 May 2007 |
| Alternative Locations: | http://dx.doi.org/10.1088/0022-3727/34/3/325 |
| Copyright Owner: | Copyright 2007 Institute of Physics and IOP Publishing Limited |
| Additional Information: | For more information, please contact the author: t.tesfamichael@qut.edu.au |