![Synthesis of nano titania particles embedded in mesoporous SBA-15: Characterization and photocatalytic activity [An article from: Journal of Hazardous Materials]](https://www.ebooknetworking.net/books/B00/0PA/bigB000PAUAM8.jpg)
Synthesis of nano titania particles embedded in mesoporous SBA-15: Characterization and photocatalytic activity [An article from: Journal of Hazardous Materials]
Description
This digital document is a journal article from Journal of Hazardous Materials, published by Elsevier in 2006. The article is delivered in HTML format and is available in your Amazon.com Media Library immediately after purchase. You can view it with any web browser.
Description:
Supported nanocrystalline titanium dioxide (TiO"2) has been prepared by a post-synthesis step via Ti-alkoxide hydrolysis through the use of mesoporous SBA-15 silica. TiO"2/SBA-15 composites with various TiO"2 loading have been prepared and characterized by X-ray diffraction, nitrogen adsorption, Fourier transform infrared spectroscopy and diffusive reflective UV-vis spectroscopy. The addition of mesoporous SBA-15 prevents the anatase to rutile phase transformation and the growth of crystal grain. TiO"2 did not block the SBA-15 pores, and their surface was fully accessible for nitrogen adsorption. Calcination in air of the composites up to 800^oC did not change the nanocrystal phase and slightly increased the domain size from 5.0 to 7.5nm, indicating that the anatase TiO"2 grains in the mesostructures have a relatively high thermal stability and proper pore diameter allows controlling the size of obtained titania particles. The TiO"2/SBA-15 composites prepared by this study showed much higher photodegradation ability for methylene blue (MB) than commercial pure TiO"2 nanoparticles P-25. Experimental results indicate that the photocatalytic activity of titania/silica mixed materials depends on the adsorption ability of composite and the photocatalytic activity of the titania, and there is an optimal ratio of Ti:Si, too high or low Ti:Si ratio will lower the photodegradation ability of the composites.
Description:
Supported nanocrystalline titanium dioxide (TiO"2) has been prepared by a post-synthesis step via Ti-alkoxide hydrolysis through the use of mesoporous SBA-15 silica. TiO"2/SBA-15 composites with various TiO"2 loading have been prepared and characterized by X-ray diffraction, nitrogen adsorption, Fourier transform infrared spectroscopy and diffusive reflective UV-vis spectroscopy. The addition of mesoporous SBA-15 prevents the anatase to rutile phase transformation and the growth of crystal grain. TiO"2 did not block the SBA-15 pores, and their surface was fully accessible for nitrogen adsorption. Calcination in air of the composites up to 800^oC did not change the nanocrystal phase and slightly increased the domain size from 5.0 to 7.5nm, indicating that the anatase TiO"2 grains in the mesostructures have a relatively high thermal stability and proper pore diameter allows controlling the size of obtained titania particles. The TiO"2/SBA-15 composites prepared by this study showed much higher photodegradation ability for methylene blue (MB) than commercial pure TiO"2 nanoparticles P-25. Experimental results indicate that the photocatalytic activity of titania/silica mixed materials depends on the adsorption ability of composite and the photocatalytic activity of the titania, and there is an optimal ratio of Ti:Si, too high or low Ti:Si ratio will lower the photodegradation ability of the composites.
