Silica-Based Thin Films for Self-Cleaning Applications in Solar Energy Converters
Publication: Journal of Energy Engineering
Volume 143, Issue 5
Abstract
Solar glass with high transmittance and low reflectance is used as glazing in solar-thermal collectors or photovoltaic modules; however, in field conditions the glazed surface can be the subject of fouling; therefore, additional prerequisites are targeting self-cleaning features while preserving or enhancing the glass optical properties. This study presents the results obtained by applying silica-based layers to the solar glass surfaces; the surface properties are tailored by controlling the roughness to modify the optical properties and improve surface wettability, supporting self-cleaning mechanisms. The sol-gel silica nanoparticles are deposited in optimized conditions, with and without titanium dioxide and gold nanoparticles; the thin layers are analyzed by X-ray diffraction, contact angle, optical measurements, and atomic force microscopy. The roughness values are influenced by the chemical composition, with lower values for the layers containing only silica and increased values when and Au nanoparticles are added. The layers have a predominant polar component of surface tension (), supporting good wettability, up to enhanced superhydrophilic features as compared with the uncoated solar glass. Additionally, the investigations under simulated solar radiation outline self-cleaning features in methylene blue removal, as a combined effect of photocatalysis and superhydrophilicity.
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Acknowledgments
The authors acknowledge the project EST in URBA, PNII-PCCA Type 2 contract no. 28/2012 financially supported by the Romanian National Research Agency.
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Published In
Journal of Energy Engineering
Volume 143 • Issue 5 • October 2017
Copyright
©2017 American Society of Civil Engineers.
History
Received: Nov 23, 2016
Accepted: Feb 10, 2017
Published online: May 10, 2017
Published in print: Oct 1, 2017
Discussion open until: Oct 10, 2017
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