Titanium dioxide (TiO2) is an attractive material for numerous technological applications such as photocatalytic applications. The photocatalysts allow the environmental purification of air and water by the decomposition of toxic organic compounds and removal of harmful gases. This work was focused on the production and evaluation of the environmental properties of titanium dioxide coatings obtained by the plasma spray technique. To carry out the step of validation of the TiO2 coatings for their environmental functionalities, a control test of the photocatalytic effectiveness was performed with respect to nitrogen oxides. A custom-designed test chamber has been developed. The photocatalytic properties of different coatings were studied as a function of various parameters (porosity, anatase/rutile ratio, nature of the substrate).