High temperature stable mesoporous anatase TiO2 photocatalyst achieved by silica addition
An aqueous sol-gel method was developed to synthesize a high temperature stable anatase titania photocatalyst by doping with silica. Doping was achieved in titania by the addition of silica sol prepared from tetra ethyl orthosilicate (TEOS). 1, 2, 5 and 15 mol% silica-titania mixed oxide were prepar...
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Published in | Applied catalysis. A, General Vol. 349; no. 1-2; pp. 13 - 19 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Amsterdam
Elsevier
31.10.2008
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Subjects | |
Online Access | Get full text |
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Summary: | An aqueous sol-gel method was developed to synthesize a high temperature stable anatase titania photocatalyst by doping with silica. Doping was achieved in titania by the addition of silica sol prepared from tetra ethyl orthosilicate (TEOS). 1, 2, 5 and 15 mol% silica-titania mixed oxide were prepared and characterised by X-ray diffraction, Raman spectroscopy, surface area analysis and diffuse reflectance spectra. Fully anatase phase was obtained at 1000 deg C by the addition of 15 mol% silica. The 15Si-Ti (15 denotes mol% of silica) had a specific surface area of 187.3 m2/g at 500 deg C and it retains a value of 93.0 m2/g at 800 deg C, whereas the undoped one shows 48.7 m2/g at 500 deg C and zero value at 800 deg C. Moreover, the 15Si-Ti composition retains the pore diameter in the mesoporous range (4.6 nm) at this high temperature of 800 deg C. The photocatalytic analysis showed that the system with silica added possessed a higher activity than pure titania. The 15Si-Ti sample calcined at 800 deg C decolourised the methylene blue dye within 30 min (rate constant 0.084 min-1), whereas the undoped sample decolourised the dye after 180 min (rate constant 0.018 min-1). The present method of preparation offers the advantages of inexpensive precursor, homogeneous distribution of the dopant over titania at nano-level and enables control over the powder characteristics of titania. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0926-860X 1873-3875 |
DOI: | 10.1016/j.apcata.2008.07.022 |