Advanced sol-gel synthesis, processing and testing of silica and silica titania multifunctional mesoporous microspheres for water purification
University of New Brunswick
The present work describes the viability of titanium dioxide doped SBA-16 type mesoporous silica microspheres for the adsorption and photocatalytic degradation of hazardous organic compounds (for example: organic dyes like crystal violet) in water. SBA-16 type mesoporous-microspheres were synthesized by a sol-gel method with Pluronic F127 employed as a structure directing agent (template) and TEOS (tetraethyl orthosilicate) as a silica source. Surface modification of these SBA-16 silica microspheres through titanium dioxide nanocrystals resulted in titanium dioxide doped SBA-16 silica microspheres. Several characterization techniques were used to analyze the microspheres. Scanning Electron Microscopy (SEM) analysis, and Transmission Electron Microscopy (TEM) analysis results show the size, sphericity and periodically ordered porous nature of the microspheres; nitrogen adsorption-desorption analysis provides information on the surface area, pore size, and pore size distribution of the microspheres; Energy Dispersive X-Ray (EDS) analysis shows the presence of titanium atoms evidencing the presence of titanium dioxide. Raman spectroscopy studies indicate formation of anatase nanocrystalline titanium dioxide. The characterization of the composite microspheres and their application in photocatalytic degradation tests confirm the viability of SBA-16 silica composite microspheres for the adsorption and photocatalytic degradation of light sensitive hazardous organic compounds in polluted waters.