Article ID Journal Published Year Pages File Type
46579 Applied Catalysis B: Environmental 2011 10 Pages PDF
Abstract

Santa Barbara Amorphous (SBA-15) mesoporous materials decorated with vary amount of TiO2 (7–31% TiO2/SBA-15) were prepared by the post-synthesis method from previously synthesized SBA-15 and their photocatalytic activity toward the degradation of methylene blue (MB) was measured. Nonionic surfactant was used as liquid template and tetraethyl orthosilicate (TEOS) as SiO2 precursor for the synthesis of mesoporous silica SBA-15. The synthesized x% TiO2/SBA-15 materials were characterized by N2 adsorption–desorption isotherms, X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), micro-Raman spectroscopy, infrared spectroscopy of framework vibration (IR-KBr) and X-ray photoelectron spectroscopy (XPS). The x% TiO2/SBA-15 photocatalysts were found to be more active than pure anatase titania and this increase was linear with TiO2 loading. The highest activity of 31% TiO2/SBA-15 sample was explained in terms of the combined factors such as a high crystallinity of anatase phase, preservation of a high surface area, a large amount of the surface hydroxyl groups, and a larger accessibility of photo-oxidative sites. A linear correlation between the apparent first order rate constants (kapp) and the amount of TiO2 species located within porous structure of the SBA-15 substrate was found.

Graphical abstractMesoporous x%TiO2/SBA-15 matrices with different amount of TiO2 (7.3–31.1 wt.%) were prepared by impregnation of the synthesized SBA-15 with titanium (IV) isopropoxide in 2-propanol. The x% TiO2/SBA-15 photocatalysts were found to be more active than pure anatase titania and this increase was linear with TiO2 loading. The highest activity of 31% TiO2/SBA-15 sample was explained in terms of the combined factors such as a high crystallinity of anatase phase, preservation of a high surface area, a large amount of the surface hydroxyl groups, and a larger accessibility of photo-oxidative sites.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Mesoporous TiO2/SBA-15 matrices as photocatalysts. ► Photocatalysts for the degradation of methylene blue. ► Particle size and photocatalytic properties were found to depend on the TiO2 loadings. ► TiO2/SBA-15 composite is more active than pure TiO2. ► Textural characteristics of mesoporous materials have great influence on the catalytic activity.

Related Topics
Physical Sciences and Engineering Chemical Engineering Catalysis
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