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.