Checking the Synergetic Effect between Anatase and Rutile

To check the synergetic effect between anatase and rutile, a series of anatase rutile-coupled TiO2 photocatalysts were prepared by calcination of the physical mixtures of amorphous TiO2 and rutile. These catalysts were characterized by scanning electron microscopy, X-ray diffraction, and ultraviolet visible diffuse reflectance spectroscopy. The photocatalytic activities of these mixed-phase photocatalysts were evaluated by photocatalytic degradation of methylene blue and photocatalytic reforming of methanol for H-2 production. The dependence of the photocatalytic activities on the anatase content, the different sources of irradiation light, and the anatase rutile interacting strength was investigated in detail. All of these results show that the photocatalytic activity increases with the increase of anatase content in the mixed-phase photocatalysts, which indicates that the synergetic effect between anatase and rutile does not work in these TiO2 photocatalytic systems.