Inclusion of FeCl3 in Sol-Gel TiO2: Spectroscopic Studies

Utilizing a sol-gel process, Fe-TiO2 materials containing 0.1, 1, 5 and 10% weight of iron were prepared at pH 3 or pH 9 using HCl or NH4OH as hydrolysis catalyst respectively. Thenceforth, the samples were annealed at 200°C, 400°C, 600°C and 800°C under airflow during 4 hours and characterized by X-ray diffraction, N2 adsorption-desorption (BET), infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy and Electron Paramagnetic Resonance (EPR). The catalytic activity of the materials was tested on a toluene combustion reaction. The results show that the cogelled iron with n-titanium butoxide slows down the anatase crystal growth. Samples of increasing iron content generate crystal size reduction. This effect is stronger passing from 0.1% to 5% Fe, but becomes weaker from 5% to 10% Fe.