“…TiO 2 has also been proposed as smart component in building materials to obtain attractive properties such as the selfcleaning, biocide and de-polluting effects [7]. Remarkably, TiO 2 has relevant capacity of degrading a wide range of pollutants and the TiO 2based photocatalytic materials are currently investigated and tested to improve the quality of the air of polluted cities [8,9]. However, TiO 2 effectiveness in outdoors applications is limited due to its light absorption restricted to the UV range, which is relatively scarce in the sunlight.…”