abstract
Detailed investigation of thermal and structural properties of mixed SiO2/TiO2 xerogels prepared via the method based on application of a precursor containing peroxo titanic acid and oligomeric silica and by the conventional co-precipitation technique has been presented. Formation of oxide phases from the xerogels prepared via the peroxo method and the co-precipitation of inorganic salts has been studied by TG/DSC, FTIR and in situ powder XRD techniques. The co-precipitation method provides higher degree of molecular homogeneity of the composite oxide, while in the case of the peroxo route segregation of the oxides takes place. The silica-titania samples prepared by the co-precipitation method include anatase phase, which is stable up to 1000 degrees C, while TiO2 in the mixed oxide synthesized by the peroxo method transits to rutile at temperatures near 800 degrees C. The presented data give no evidence for formation of Si-O-O-Ti peroxo bridges in the xerogels prepared via the peroxo method. Peroxo groups in the silica-titania xerogels synthesized via the peroxo-method have been found to be more stable in silica-rich samples, compared to pure titania. Thus, these materials hold promise for application as catalysts in oxidation reactions and photocatalysis. (C) 2014 Elsevier B.V. All rights reserved.
keywords
MODIFIED ANATASE SOL; PEROXOTITANIC ACID-SOLUTION; TIO2 THIN-FILM; HETEROGENEOUS PHOTOCATALYSIS; PHYSICOCHEMICAL PROPERTIES; HYDROTHERMAL METHOD; HYDROGEN-PEROXIDE; GEL; CATALYSTS; OXIDES
subject category
Chemistry
authors
Ilkaeva, M; Krivtsov, I; Avdin, V; Khainakov, SA; Garcia, JR
our authors
Marina Ilkaeva
Junior Researcheracknowledgements
The study is carried out within the grant of Spanish MINECO (MAT2010-15094). Marina Ilkaeva thanks the financial support by the "UMNIK" grant for young scientists no. 0000842.