A comparative study of different porous amorphous silica minerals supported TiO2 catalysts

Authors: Zhiming Sun, Chunhua Bai, Shuilin Zheng, Xiaoping Yang, Ray L. Frost

Abstract:
Three porous amorphous silica minerals, including diatomite, opal and porous precipitated SiO₂ were adopted to prepare supported TiO₂ catalysts by hydrolysis–deposition method. The prepared compound materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Through morphology and physical chemistry properties of the resulting TiO₂/amorphous SiO₂ catalysts, it was proposed that the nature of silica supports could affect the particle size andthe crystalformof TiO₂ andthenfurther influence thephotocatalyticproperty of TiO₂/amorphous SiO₂ catalysts. The catalytic properties of these porous amorphous silica supported photocatalysts (TiO₂/SiO₂) were investigated by UV-assisted degradation of Rhodamine B (RhB). Compared with pure TiO₂ (P25) and the other two TiO₂/amorphous SiO₂ catalysts, TiO₂/diatomite photocatalyst exhibits better catalytic performance at different calcined temperatures, the decoloration rate of which can be up to over 85% even at a relatively low calcined temperature. The TiO₂/diatomite photocatalyst possesses mixed-phase TiO₂ with relatively smaller particles size, which might be responsible for higher photocatalytic activity. Moreover, the stable and much inerter porous microstructure of diatomite could be another key factor in improving its activity.

Keywords:
TiO₂
Diatomite
Opal
Porous precipitated SiO₂
Photocatalytic activity

Published in: Applied catalysis A: General  (Volume 458, Pages 1-206, 10 May 2013)

Publisher: Elsevier

ISSN Information: 0926-860X

A comparative study of different porous amorphous silica minerals supported TiO2 catalysts

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