Entire photocatalytic tiles (60x60cm) evaluation in NOx degradation in a continuous bench-scale reactor

Pigmentary and micrometric commercial TiO2 was successfully deposited on porcelain gr\ue8s tiles, which were tested on the NOx photodegradation, showing a very good photocatalytic activity; the reactor structure allows to test tiles of size 60x60 cm directly, simulating in a very realistic way their ability to make better air quality. In particular, we show a reproducible way to test material in industrial scale and not just in laboratory scale. The TiO2 powders are commercial and micrometric, regardless of which there are no papers in literature. As well as to demonstrate that micrometric TiO2 can be used in photocatalysis, it is important to underline that it is less dangerous for health than the nano-powders, it is easier to handle and, not less important, it is absolutely cheaper. Nowadays it is so important to find new strategies to clean the environment and the possibility to reduce the greenhouse gases emissions is increasingly in demand; NOx in particular are strictly monitored all over the world. TiO2 photocatalysis is a promising technique to break down pollutants and it is possible to directly use it on building materials: however, find a serious and reproducible way to test them and confirm their photo-efficiency would be significant. Although a lot of different reactors have already been developed1,2, they work with small samples and the conditions are often very far from the reality. In this work a reactor able to test photocatalytic building materials in large size is presented, working both under artificial and solar light: the porcelain gr\ue9s tiles was provided by GranitiFiandre, and they are industrially prepared making use of a particular commercial micro-sized TiO2, according with the fact that TiO2 nanoparticles can cause negative health effects3. First the photo-activity of these building materials has been demonstrated, showing off their real power to degrade nitrogen oxides. No less important, however, is the creation of a system in which is possible to work with samples of tiles with a size of 3600 cm2, coming very close to reality. In particular, we made a comparison of different source of light, working both under UV and solar, and we performed degradation kinetics of different duration, from a few hours to days. Therefore a complete picture of data is proposed, with an accurate description of the phenomenon