Preparation and Characterization of Cu-doped TiO2 nanomaterials with Anatase/rutile/brookite Triphasic Structure and their Photocatalytic Activity

Abstract Pure TiO2 and different concentrations of Cu–doped TiO2 with anatase/rutile/brookite triphasic structure were successfully synthesized through a simple hydrothermal process and characterized by X–ray diffraction (XRD), Raman, scanning electron microscope (SEM), transmission electron microscope (TEM), X–ray photoelectron spectra (XPS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL) and Brunauer-Emmett-Teller surface area (BET). Both pure and Cu–doped TiO2 show relatively high photocatalytic activity owing to their considerable surface areas. Moreover, the three–phase coexisting structure and the conversion between Cu2+ and Cu+ ions facilitate the separation of photogenerated electrons and holes, which is favorable for photocatalytic performance. 1%Cu–TiO2 exhibits the highest photocatalytic activity and the degradation degree of rhodamine B (RhB) reaches 93.5% after 30 min, which is higher than that of monophasic/biphasic 1%Cu–TiO2. ·O2− radical is the main active specie, and h+ and ·OH are subsidiary in the degradation process.