Phase transformation of anatase-rutile crystals in doped and undoped TiO₂ particles obtained by the oxidation of polycrystalline sulfide

The anatase-rutile phase transformation of doped and undoped TiO₂ is discussed on the basis of crystal chemistry and the photoelectric oxidation properties of the mixture phase using different parameters. The X-ray diffraction (XRD) results confirm that temperature and time affect the anatase-rutile transformation, whereas the Fe-dopant concentrations had no effect on the anatase-rutile transformation. Field Emission Scanning Electron Microscope (FE-SEM) studies also indicate the presence of single anatase and anatase-rutile mixed phase structures on the surface of TiO₂. X-ray photoelectron spectroscopy (XPS) was used to investigate the Ti state in the final product. The coexistence of the anatase-rutile mixture in TiO₂ particles caused significant light absorption and higher degradation efficiency by the synergism between rutile and anatase particles.