Insight into the structure and localization of the titania overlayer in TiO2-coated SBA-15 materials
Résumé
Titania-coated SBA-15 materials (Ti-SBA-n with n = 1-4) were synthesized by successive grafting of titanium isopropoxide in iso-propanol. The investigation of the nature and localization of the TiO2 overlayer allowed us to conclude that there was formation of very small (UV-visible, EXAFS, XANES), ca. 2 nm or smaller (XRD and TEM) TiO2 domains that cover only partially the silica surface (CO adsorption). These nano TiO2 domains are located on or close to the mesopore surface (EELS, XRD and N2-sorption) rather than in the micropores as previously reported. [on SciFinder(R)]