Preparation of Ti3+ Self-Doped TiO2(A)/TiO2(R)/In2O3 Nanoheterojunctions with Enhanced Visible-Light-Driven Photocatalytic Properties

Ti3+ self-doped TiO2(A)/TiO2(R)/In2O3 nanoheterojunctions were synthesized by hydrothermal treatment of the precursor obtained using TiCl3 and InCl3 as the Ti and In source without the exist of reductant. The effects of hydrothermal treatment temperature on the properties of the samples were studied. The structure, crystallinity, morphology, chemical state and optical properties of the obtained samples were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectroscopy. Rhodamine B (RhB) and phenol solutions were used as simulated wastewater to evaluate the visible-light photocatalytic activity of the nanoheterojunctions. The Ti3+ self-doped TiO2 (A)/TiO2 (R)/In2O3 nanoheterojunctions exhibited extended visible light absorption and higher photocatalytic activity than that of pure TiO2, In2O3 and Ti3+ self-doped TiO2. The sample obtained after hydrothermal treatment at 200 degrees C for 24 h exhibited the best visible light photocatalytic activity with a reaction rate constant of 0.044 4 min(-1), 17.76 and 8.71 times than that of pure TiO2 and In2O3. Photocurrent density results indicated that the improved visible-light photocatalytic properties which could be attributed to the enhanced photogenerated charge separation of the nanoheterojunction.