TiO2 nanoparticles with interesting physicochemical properties were synthesized by means of the sol-gel method and acid hydrolysis. The obtained nanoparticles were characterized by the X ray diffraction (XRD), Rietveld refinement, Brunauer Emmett Teller (BET) and transmission electron microscopy (TEM) techniques, and tested in the photodecomposition of NOx. The NOx decomposition degree reached by the sol-gel TiO2 nanoparticles was directly proportional to the brookite mass fraction, but inversely proportional to both the anatase mass fraction and the crystal size.
