TiO2/SiO2 membrane materials via a sol-gel process: preparation and characterization calcined under N2 atmosphere

The study presents the synthesis of TiO2/SiO2 membrane materials using sol-gel method by hydrolysis of tetrabutyl titanate (TBOT) with ethanol and water mixture as titania source, tetraethylorthosilicate (TEOS) and methyltriethoxysilane (MTES) as silica source. The microstructure of the composites were characterized by X-ray diffraction (XRD), fourier transform infrared (FTIR) spectra, scanning electron microscopy (SEM), energy dispersive spectrum (EDS), N-2 absorption-adsorption measurement and thermogravimetric-differential thermogravimetric (TG-DTG) analysis. The as obtained TiO2/SiO2 membrane materials showed the existence of Si-O-Ti, which indicates that the SiO2 is chemically bonded with the TiO2 particles. The TiO2 nanoparticles have entered into the channels of SiO2 network. The TiO2-doping decreased the mean pore diameter, and increased the surface area and porosity of SiO2 materials. The TiO2/SiO2 membrane materials with Ti/Si molar ratio of 0.4 exhibit a large BET surface area (up to 284.04 m(2)/g) and total pore volume (up to 0.272 cm(3)/g), as well as a mean pore diameter of about 2.49 nm.