Investigation on Parameters Affecting the Effectiveness of Photocatalytic Functional Coatings to Degrade NO: TiO 2 Amount on Surface, Illumination, and Substrate Roughness

• Published in: International journal of photoenergy Vol. 2017; pp. 1 - 14
• Main Authors: Hot, J., Topalov, J., Ringot, E., Bertron, A.
• Format: Journal Article
• Language: English
• Published: 2017
• ISSN: 1110-662X; 1687-529X
• DOI: 10.1155/2017/6241615

This paper deals with the degradation of NO by photocatalytic oxidation using TiO 2 -based coatings. Tests are conducted at a laboratory scale through an experimental setup inspired from ISO 22197-1 standard. Various parameters are explored to evaluate their influence on photocatalysis efficiency: TiO 2 dry matter content applied to the surface, nature of the substrate, and illumination conditions (UV and visible light). This article points out the different behaviors between three kinds of substrates which are common building materials: normalized mortar, denser mortar, and commercial wood. The illumination conditions are of great importance in the photocatalytic process with experiments under UV light showing the best results. However, a significant decrease in NO concentration under visible light is also observed provided that the TiO 2 dry matter content on the surface is high enough. The nature of the substrate plays an important role in the photocatalytic activity with rougher substrates being more efficient to degrade NO. However, limiting the roughness of the substrate seems to be of utmost interest to obtain the highest exposed surface area and thus the optimal photocatalytic efficiency. A higher roughness promotes the surface contact between TiO 2 and NO but does not necessarily increase the photochemical oxidation.