Photocatalytic and superhydrophilic phenomena of TiO2 coated clay roofing tiles

Abstract

The coating procedure of clay roofing tiles was obtained using a simple spraying technique of a laboratory made TiO2 suspension. This was followed by a thermal treatment at 120/150 °C (τ = 30 min). The defined mass % of TiO2, grain size value of TiO2 and its crystal form were the main characteristics of the designed suspensions. The tile samples were studied in their progressive ageing with exposure to visible light and water rinsing procedure. The photocatalytic activity of the coatings was determined after visible irradiation (sun and artificial light) of the defined intensity (I = 80 W/m2) through the measurements of the absorption values of the rhodamine B, while the results of the superhydrophilic property were obtained based on the measurements of the water contact angle. Considering the energy consumption, it was shown that the tile products based on the new designed suspension could be produced in already existing industrial dryers using the existing waste heat in the industrial line.

Keywords

• clay roofing tiles
• titania
• photocatalytic activity
• superhydrofilicity.