Post-Synthesis of Ti-SBA-15 in Supercritical CO2-Ethanol Solution

Ti-SBA-15 materials with Ti incorporated into the framework of SBA-15 and controllable Ti contents were successfully prepared via a post-treatment route in supercritical CO2-ethanol solution, followed by calcination. The resultant Ti-SBA-15 materials were characterized by means of different techniques including X-ray diffraction, Xray photoelectron spectroscopy, transmission electron microscopy, IR analysis, and N-2 sorption analysis. It was demonstrated that the resultant materials retained a structure similar to that of the parent SBA-15, and Ti was incorporated into the framework of SBA-15. At high Ti content, Le, Si/Ti = 5:1, a TiO2 phase formed and was coated onto the inner surface of SBA-15 in addition to the incorporation of the Ti in the framework. The BET surface areas of the Ti-SBA-15 samples decreased with increasing Ti content. The presence of small amounts of H2O in the reaction medium may have resulted in some TiO2 nanoparticles being uniformly distributed in the pores of the SBA-15 accompanying the incorporation of Ti in the SBA-15 framework.