Photocatalysis with modified titania is a promising approach to improve both air and health quality. Modified titania with novel photocatalytic properties under indoor light irradiation leads to smart coatings, which are benchmark materials suitable for their indoor applications. It is generally accepted that the photocatalytic activity is affected by the light absorption, charge creation/recombination rate and surface reactivity. In this contribution we focus on modified TiO2 as catalyst in heterogeneous photo-catalytic processes and address the efficiency of TiO2-based building and construction materials on the removal of environmental pollutants indoors and outdoors. We also present data on the presence of eventually formed, toxicologically relevant and harmful by-products as the result of the photo-induced degradation of pollutants in an effort for better evaluation of induced risks for human health from the application of TiO2 modified materials. Finally, we present recent results on the disinfection performance of these material and the inactivation of severe pathogens contained in water and indoor air environments

Hybrid lead halide spin coated perovskite films have been successfully tested as portable, flexible, operated at room temperature, self-powered, and ultrasensitive ozone sensing elements. The electrical resistance of the hybrid lead mixed halide perovskite (CH₃NH₃PbI_3–xCl_x) sensing element, was immediately decreased when exposed to an ozone (O₃) environment and manage to recover its pristine electrical conductivity values within few seconds after the complete removal of ozone gas. The sensing measurements showed different response times at different gas concentrations, good repeatability, ultrahigh sensitivity and fast recovery time. To the best of our knowledge, this is the first time that a lead halide perovskite semiconductor material is demonstrating its sensing properties in an ozone environment. This work shows the potential of hybrid lead halide based perovskites as reliable sensing elements, serving the objectives of environmental control, with important socioeconomic impact.