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

The characterization of nano-sized TiO ₂ and Fe/TiO ₂ 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/TiO ₂ 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 TiO ₂ and Fe/TiO ₂ are located at binding energies of 459 and 465 eV, respectively, which represent the values of Ti ⁴⁺ in the TiO ₂ 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 TiO ₂ between water vapor and 1,2-DCE. The byproducts of 1,2-DCE photodegradation include H ₂ O, CO, CO ₂ , C ₂ H ₅ Cl, CH ₂ Cl ₂ , and HCl.