Development of visible light active self-cleaning clay roofing tiles as novel building materials: An investigation on the effects of α-Fe2O3 coating and firing temperature

In this study, in order to obtain visible light active self-cleaning property while maintaining physical stability, clay roofing-tiles were first prepared at several firing temperatures of the clay and coated with α-Fe2O3 films followed by a heat treatment. Pristine (uncoated) and coated samples then were compared in terms of i) physical properties as aesthetic appearance, stability against environmental conditions and ii) photocatalytic properties as self-cleaning characteristics under visible light by artificial pollutant, methylene blue (MB).