Preparation and characterization of heterojunction semiconductor YFeO₃/TiO₂ with an enhanced photocatalytic activity

YFeO₃/TiO₂ heterojunction semiconductors were prepared by the milling–annealing method. Effects of structure and surface phase by annealing temperature and TiO₂ weight content were investigated. The physical and photophysical properties of heterojunction semiconductors were characterized by x-ray diffraction (XRD), UV-visible diffraction (UV-vis/DRS), and x-ray photoelectron spectroscopy (XPS), N₂ adsorption. YFeO₃ is presented as p-type semiconductor and disperses on the surface of n-type TiO₂ to constitute a heterojunction composite. Results show that the presence of p–n junction not only has visible light harvesting but potential force for hole–electron pair separation. A preliminary investigation of photodegradation effect on Orange II showed that YFeO₃/TiO₂ heterojunction semiconductors exhibited better photocatalytic properties than the single phase of YFeO₃ or TiO₂. The ideal heterojunction semiconductor composition was ω (TiO₂) = 0.9 sample annealed at 600 °C. The mechanism of the electric-field-driven electron–hole separation initiated by the chemically bonded p–n heterojunction and enhanced photocatalytic activity were discussed.