Titania-silica composites with less aggregated particles

Less aggregated titania-silica composite was developed by a versatile and reproducible method using relatively cheap precursors. The final product has more suitable properties than the conventional materials. The composite was synthesized by using sodium silicate, as a silica precursor, and freshly prepared TiOCl2 as a titania source. The final product was obtained after subsequent calcination for 5 h at 300 to 1000 degrees C. The primary particles of the composite, as examined by SEM technique, are generally less aggregated. The XRD patterns for the calcined samples indicate the presence of TiO2 and there is a significant increase of peak intensity as the calcination temperature increases. EDS and XPS analyses confirmed the formation of pure composite rich in Ti, Si, and O. Nitrogen physisorption studies reveal that the composite is mesoporous and have large BET surface area (similar to 375 m(2)/g). A simple experiment of photoreduction of methyl orange under solar radiation was attempted to demonstrate the reliability and improvement of titania-silica composite in practice. It was found out that its efficiency is high as compared to P-25 TiO2 under solar light. The results demonstrate that composite with desirable properties for various applications can be obtained via the present route. (C) 2009 Elsevier B.V. All rights reserved.