title: Fe effect on the optical properties of TiO2:Fe2O3 nanostructured composites supported on SiO2 microsphere assemblies.
abstract: The effect of Fe ion concentration on the morphological, structural, and optical properties of TiO2 films supported on silica (SiO2) opals has been studied. TiO2:Fe2O3 films were prepared by the sol-gel method in combination with a vertical dip coating procedure; precursor solutions of Ti and Fe were deposited on a monolayer of SiO2 opals previously deposited on a glass substrate by the same procedure. After the dip coating process has been carried out, the samples were thermally treated to obtain the TiO2:Fe2O3/SiO2 composites at the Fe ion concentrations of 1, 3, and 5 wt%. Scanning electron microscopy (SEM) micrographs show the formation of colloidal silica microspheres of about 50 nm diameter autoensembled in a hexagonal close-packed fashion. Although the X-ray diffractograms show no significant effect of Fe ion concentration on the crystal structure of TiO2, the μ-Raman and reflectance spectra do show that the intensity of a phonon vibration mode and the energy bandgap of TiO2 decrease as the Fe(+3) ion concentration increases.
authors.affiliation: Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apdo. Post. J-48, Puebla Pue. 72570, México.
authors.forename: Jesús I
authors.initials: JI
authors.lastname: Peña-Flores
authors.affiliation: Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apdo. Post. J-48, Puebla Pue. 72570, México.
authors.forename: Abraham F
authors.initials: AF
authors.lastname: Palomec-Garfias
authors.affiliation: Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apdo. Post. J-48, Puebla Pue. 72570, México.
authors.forename: César
authors.initials: C
authors.lastname: Márquez-Beltrán
authors.affiliation: Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apdo. Post. J-48, Puebla Pue. 72570, México.
authors.forename: Enrique
authors.initials: E
authors.lastname: Sánchez-Mora
authors.affiliation: CIDS-IC, Benemérita Universidad Autónoma de Puebla, Apdo. Post. 196, Puebla Pue. 72000, México.
authors.forename: Estela
authors.initials: E
authors.lastname: Gómez-Barojas
authors.affiliation: Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apdo. Post. J-48, Puebla Pue. 72570, México.
authors.forename: Felipe
authors.initials: F
authors.lastname: Pérez-Rodríguez
keywords: Dip coating; Nanostructured composites; SiO2 microsphere assemblies; Sol-gel; TiO2:Fe2O3 films