Titania-Phosphotungstic Acid Nanocomposites Dispersed Homogeneously in Mesopores as the Recyclable Photocatalyst
Heterogeneous photocatalytic materials, titania–phosphotungstic acid nanocomposites in the mesopores of SBA-15 (TiO2-H4PW12O40/SBA15) were prepared by sol–gel method. Compositions and structures of the nanocomposites were characterized by X-ray diffraction (XRD), UV-visible absorption spectroscopy and transmission electron microscopy (TEM). Uniform mesoporous SBA15 consisting of long-range channels provides the immobilization of titania-phosphotungstic acid nanocomposites. The photocatalytic activity of the prepared TiO2-H4PW12O40/SBA15 powders was evaluated from an analysis of the photocatalytic degradation of methyl orange. The results indicated that photocatalytic activity increased with the amount of H4PW12O40 from 0% to 10% and decreased when the amount of H4PW12O40 was above 10%. It is due to the synergetic reaction of H4PW12O40 and TiO2. However, much more H4PW12O40 can occupy the active center of TiO2. TiO2 can inhibit the decomposition of H4PW12O40 in the TiO2-H4PW12O40/SBA15 composites. On the other hand, H4PW12O40 repressed the TiO2 particle growth during calcination process. The composite catalyst also had the advantage of easily being recovered and reused.
Zhengyi Jiang, Jingtao Han and Xianghua Liu
H. L. Zhou et al., "Titania-Phosphotungstic Acid Nanocomposites Dispersed Homogeneously in Mesopores as the Recyclable Photocatalyst", Advanced Materials Research, Vols. 152-153, pp. 202-207, 2011