Nonhydrolytic layer-by-layer surface sol-gel modification of powdered mesoporous silica materials with TiO ₂

The nonhydrolytic surface sol-gel (NSS) process, which was used for the layer-by-layer modification of mesoporous silica materials (SMA-15) with TiO ₂, was described. The SBA-15 materials had hexagonally packed channels with pore sizes of ∼8.5 nm. The low-angle X-ray diffraction patterns of SBA-15 and monolayer-, double-layer-, and triple-layer-covered SBA-15 showed that the hexagonal structure of the SBA-15 was retained during the NSS layer-by-layer functionalization. The results show that the process can be expanded to modify other powdered materials that contain active hydroxyl groups with unitary or mixed metal oxides.