Journal of Nanomedicine & Nanotechnology

Properties of the laser treated tubular cobalt- alumina nanocomposite selective solar absorber

7^th World Nano Conference

June 20-21, 2016 Cape Town, South Africa

A Karoro, Z Y Nuru, C Kotsedi, Kh Bouziane, B M Mothudi and M Maaza

University of South Africa, South Africa
Nano sciences African Network, South Africa
University of South Africa, South Africa

Posters & Accepted Abstracts: J Nanomed Nanotechnol

Abstract:

This work reports on the structural and optical properties of laser surface structured Co nano cylinders-Al2O3 cermets for enhanced solar selective absorbers applications. The electro deposition of the Co nano cylinders into the porous alumina arrays is a suitable technique to produce nano materials, since highly ordered uniform nano materials can be obtained simply and in a cost effective way. A femtosecond fiber laser pulsing at the fundamental wavelength of 1064 nm was used to surface structure the thin film Co-Al2O3 composites. The structural and chemical properties were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive spectrometry and atomic force microscopy; their optical characteristics were investigated by specular & diffuse reflectance. The optimized samples exhibit an elevated optical absorptance above 98% and an emitance ~0.03 in the spectral range of 200-1100nm which make them potential candidates as mid-temperature selective solar absorbers. This set of values was suggested to be related to several surface and volume phenomena such as light trapping, plasm on surface effect as well as angular dependence of light reflection induced by the ultrafast laser multi-scale structuring.

Biography :

Ms. Angela karoro, originally from Uganda is a carrying out her PhD studies in selective solar absorbers for Concentrated Solar Power at the University of South Africa under the framework of the UNESCO UNISA Africa Chair in Nanosciences & Nanotechnology. She is an awardee of the German Academic Exchange Service and the Joint-US Africa Materials Institute as well as the African Laser Centre.

Email: angela@tlabs.ac.za