Synthesis and characterization of TiO2 and Fe/TiO2 nanoparticles and their performance for photocatalytic degradation of 1,2-dichloroethane

The characterization of nano-sized TiO2 and Fe/TiO2 prepared by a sol-gel method was characterized in this study. The synthesized photocatalysts were used for the photodegradation of 1,2-dichloroethane (1,2-DCE). From X-ray powder diffraction data, the crystal phase presents a mixture of anatase and rutile with anatase the dominant phase. As seen in TEM images, the crystallites of photocatalysts are spherical particles with a crystallite size about 10-20 nm. UV-vis absorption spectra of Fe/TiO2 show a slightly increase in absorbancy in the visible light region with the increasing iron ion doping concentration. The X-ray photoelectron spectroscopy (XPS) results indicate that the Ti 2p(3/2) and Ti 2p(1/2) photoelectrons for TiO2 and Fe/TiO2 are located at binding energies of 459 and 465 eV, respectively, which represent the values of Ti4+ in the TiO2 lattices. The XPS data also indicate that the doped Fe ions exist in the forms of Fe(III). The Fe(III) may alleviate the surface poison phenomenon and act as both h(+)/e traps to reduce the recombination rate of h(+)/e pairs, and the optimum iron doping amount is 0.001 mol%. From 1,2-DCE photocatalytic degradation, the photocatalytic performance is a function of retention time and it would have a competitive adsorption on the active site of TiO2 between water vapor and 1,2-DCE. The byproducts of 1,2-DCE photodegradation include H2O, CO, CO2, C2H5Cl, CH2Cl2, and HCl. (C) 2008 Elsevier B. V. All rights reserved.