title: New generation photocatalysts: how tungsten influences the nanostructure and photocatalytic activity of TiO2 in the UV and visible regions.
abstract: Tungsten-doped anatase was prepared by a thermal hydrolysis of aqueous solutions of peroxo complexes of titanium and tungsten. The synthesized samples included X-ray diffraction, high-resolution transmission electron microscopy, selected area electron diffraction, Raman spectroscopy, specific surface area, and porosity determination. W doping resulted in a decrease of the unit-cell volume of anatase at lower W contents and an increase at higher W contents. The position of the most intense Raman band of the E(g) mode (near 147 cm(-1)) also has a local minimum at medium-doped titania (1.1-3.6% W in titania). W doping increases the temperature of anatase-to-rutile transformation by about 100 °C compared with nondoped anatase. The photocatalytic activity of doped titania samples was determined by decomposition of Orange II dye during irradiation at 365 and 400 nm. Specimens with moderate W doping (1.0-3.3% W) perform best: they enhance the corresponding reaction rates 10 times at 365 nm and 5 times at 400 nm, respectively, compared with pure titania obtained under the same set of synthesis conditions.
authors.affiliation: Department of Solid State Chemistry, Institute of Inorganic Chemistry AS CR v.v.i. , 250 68 Řež, Czech Republic. stengl@iic.cas.cz
authors.forename: Václav
authors.initials: V
authors.lastname: Štengl
authors.forename: Jana
authors.initials: J
authors.lastname: Velická
authors.forename: Monika
authors.initials: M
authors.lastname: Maříková
authors.forename: Tomáš Matys
authors.initials: TM
authors.lastname: Grygar