Sustainable photocatalytic porcelain grés slabs active under LED light for indoor depollution and bacteria reduction

At the beginning of the industrial productions, porcelain grés tiles were considered as just a technical material, esthetically not very beautiful. Today thanks to new industrial production methods, both properties and beauty of these materials completely fit the market requests. Besides these noteworthy architectural features, new surface properties have been introduced in the last generation of these materials. In particular, deposition of TiO2 transforms the traditional ceramic into a photocatalytic eco-active material able to reduce polluting molecules present in air and water, to eliminate bacteria, and to reduce the surface dirt thanks to the self-cleaning property. The problem of photocatalytic materials resides in the fact that it is necessary an ultraviolet (UV) light source to activate the oxidation processes on the surface of the material, processes that are turned off inexorably when the material is illuminated by LED lights and, even more so, when we are in darkness. The commercial TiO2, which is used for the traditional photocatalytic coating, has been doped with metals in order to activate it even in the visible region and thus in the presence of sunlight or LED. The presence of dopant metals (patent WO2016157155), specifically Ag, also allows the material to work as well as antibacterial in the dark, by eliminating one of the negative features of photocatalytic building materials. This chapter will report all the material characterization and photocatalytic tests including antibacterial tests (under UV, LED, and in the dark as well), from the most common such as Escherichia coli to the most dangerous such as methicillin-resistant Staphylococcus aureus.