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Keywords:

Photocatalysis, Titanium dioxide, Self-cleaning, Water-to-cement ratio, Soot, Carbon, Science & Technology, Physical Sciences, Technology, Chemistry, Applied, Chemistry, Physical, Engineering, Chemical, Chemistry, Engineering, OXIDATION, WATER, TIO2, FORMALDEHYDE, FUNDAMENTALS, EFFICIENCY, BEHAVIOR, KINETICS, REMOVAL, 03 Chemical Sciences, 09 Engineering, Physical Chemistry, 34 Chemical sciences, 40 Engineering

Abstract:

Soot deposition has the negative ability to devalue the aesthetic appearance of buildings. Titanium dioxide applied on the building material is one way to counteract this problem as it provides air-purifying and self-cleaning properties due to its photocatalytic activity. In literature, photocatalytic soot oxidation was described, but until now, little information was available about the influence of process parameters on the photocatalytic degradation efficiency. The influence of three process parameters was tested in this study, namely TiO2 concentration, soot concentration and water-to-cement ratio (W/C-ratio) of the mortar substrates. The results revealed 50 μg TiO2 cm-2 is better to use on the cementitious materials than 250 μg TiO2 cm-2. The soot concentrations occurring in real-world situations will not inhibit the photocatalyst to be activated by light. Furthermore, the photonic efficiency increases slightly for lower W/C-ratios. This can be of interest for structural building applications, since a lower W/C-ratio results in a lower porosity of the samples and consequently in an increase in mortar strength. © 2013 Elsevier B.V.