Surface sol-gel modification of mesoporous silica molecular sieve SBA-15 with TiO2 in supercritical CO2

Mesoporous silica molecular sieve SBA-15 has been grafted with monolayer and doublelayer of titanium dioxide via surface sol-gel process in supercritical carbon dioxide (SC CO2). The materials were characterized by nitrogen adsorption, X-ray photoelectron, X-ray diffraction (XRD), and Raman spectroscopy. The results suggest that the incorporated titanium dioxide is present mainly as anatase phase. The pore diameter decreases with the modification cycle number, and the titanium dioxide exists as a 5 Å thick film chemically anchored on the mesopores of SBA-15.