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

Abstract

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), N₂ 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 m²/g) and total pore volume (up to 0.272 cm³/g), as well as a mean pore diameter of about 2.49 nm.

Keywords:

• Sol–gel process
• TiO₂/SiO₂ membrane materials
• surface area
• porosity

Additional information

Funding

The authors acknowledge the financial assistance from the National and Science Foundation Council of China 21573171 and Shaanxi Province Key Research and Development Plan of China 2017GY-121.