Facile Synthesis of F-TiO2/TiOF2 Mixture by High-Thermal Direct Fluorination and Its Photocatalytic Evaluation

In this study, the mixture of F-TiO2/TiOF2 has been easily synthesized using titanium (IV) isopropoxide (TTIP) as titanium source by direct fluorination at high temperature according to different partial pressure of fluorine gas. The morphological properties and crystalline of thermally fluorinated photo-catalysts were investigated using scanning electron microscope (SEM) and X-ray diffraction (XRD). Chemical composition and optical properties of thermally fluorinated photocatalysts were analyzed by X-ray Photoelectron Spectroscopy (XPS) and Photoluminescence (PL) spectrometer. The phase of F-TiO2/TiOF2 mixture was generated with different proportion by high-thermal direct fluorination. With the increase of the fluorine partial pressure, the proportion of cubic-shaped TiOF2 increased in comparison with globular-shaped TiO2. Also, the degradation rate constant of thermally fluorinated photocatalysts exhibited approximately 70 times more than that of TiO2, which were not treated fluorine gas. It is attributable to the increase of the surface hydroxyl group content and oxygen vacancies.