Characterization of Ti/SBA-15 Composites Synthesized by Chemical Vapour Deposition of Organic Titanium Compounds

Abstract

The chemical vapour deposition technique was applied to obtain Ti/SBA-15 composites. Titanium(IV) tetraisopropoxide (TTIP) and titanium(IV) tetrabutoxide (TNBT) as sources of TiO2 were deposited on mesoporous silica (SBA-15) from the gaseous phase at 180–200 °C and treated at 250 °C in air. X-ray diffraction, Fourier-transform infrared spectroscopy, and Raman spectroscopy were used for structural investigations. Moreover, energy-dispersive X-ray spectroscopy studies and electrophoretic mobility measurements were conducted. Investigations revealed that Ti ions were mainly deposited on the SBA-15 surface as a thin layer of amorphous TiO2. However, Ti ions were not detected in the composites synthesized using TNBT as the starting reagent. The thickness of the deposited titanium oxide layer was estimated as 6–7 nm, and the porous silica structure has not been damaged. Moreover, the Ti ions deposition on the SBA-15 surface did not significantly change the investigated Ti/SBA-15 composites’ thermal stability compared to pristine silica.

Keywords

• chemical vapour deposition
• mesoporous silica
• SBA-15
• surface modification