Nanostructured ceria supported on SiO2 catalysts were synthesized using four different preparation
procedures: (1) cerium nitrate adsorption, (2)ammonia precipitation, (3)citric acid sol-gel method and (4)citric
acid-ammonia complex method. Thermo gravimetry-differential scanning calorimetry (TG-DSC) was used to
analyze the weight loss and crystallization behavior of the precursor made by four synthesis procedures during
heat treatment. The synthesis effects on the size, dispersion, crystallinity and photocatalytic property of
ceria supported on SiO2 were characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), ultraviolet-visible diffuse reflectance spectra (UV-Vis/DRS), hydrogen
temperature-programmed reduction (H2-TPR) and photocatalytic degradation of methylene blue. The result shows that ceria supported SiO2 catalyst synthesized by sol-gel method has the best dispersibility
and photocatalytic performance, lowest crystallinity, smallest grain size and band gap.
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