N-doped TiO2 from TiCl3 for photodegradation of air pollutants

The photocatalytic activity of both commercial and homemade N-doped TiO2 samples, prepared at different pH from TiCl3 solutions, was tested for the degradation of toluene in the gas phase by using a solar irradiation source. Highest degradations and corresponding kinetic constants were achieved in the case of N-doped samples prepared at higher pH. Various adsorbed aromatic species (benzoic acid, the major surface product, benzylic alcohol, benzaldehyde) were observed at the surface of the exhaust catalysts by using FTIR-ATR spectroscopy. The trend of the photocatalytic efficiency in the visible region is discussed with respect to structural (XRD), morphological (BET, TEM), surface (XPS) and paramagnetic (EPR) characterization.