Influence of titania content on the mesostructure of titania–silica composites and their photocatalytic activity
No Thumbnail Available
Date
Journal Title
Journal ISSN
Volume Title
Publisher
Powder Technology
Abstract
Description
Titania–silica composites (TSC) with various Ti/Si ratios were synthesized via sol–gel process using less
expensive precursors; sodium silicate solution as a silica source and titanium oxychloride as a titania source.
The influence of varying Ti content in the composites was examined by FTIR, SEM, TEM, DTA/TGA, N2
physisorption studies, XRF and XRD. The BET surface area of the raw materials increased with increasing Ti/Si
ratio up to 2.9 (461 m2/g) but further increase of Ti content beyond that ratio yielded compositeswith decreased
surface area. The effect of aging evaluated in the samplewith Ti/Si=2.9 revealed that aging the composite for 2 h
yields titania–silica powderwith the highest surface area (461 m2/g). The FTIR analysis displayed the presence of
a vibration band at 945 cm−1, assignable to hetero linkage of the Si–O–Ti depicting the incorporation of TiO2 into
SiO2 to form a composite.Moreover, photodegradation of methyl orange (MO) by the samples calcined at 800 °C
showed that the TSC-5-800 (Ti/Si=5.6) exhibited the highest maximum photocatalytic activity of all the
composites.