Preparation and photocatalytic activity of La3+ and Eu3+ co-doped TiO2 nanoparticles: photo-assisted degradation of methylene blue

Rare earth ions La3+ and Eu3+ co-doped TiO2 photocatalyst (La-Eu/TiO2) was prepared by sol-gel method, and characterized by various techniques such as X-ray diffraction (XRD), specific surface area and porosity (BET and BJH), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), UV-vis diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of the La-Eu/TiO2 was evaluated by the degradation of methylene blue (MB) under UV light irradiation. The catalyst had a relatively uniform particle diameter distribution in the range of 40–60 nm. When calcining at 600°C, the XRD patterns of La-Eu/TiO2 indicated the anatase phase, while the XPS patterns showed the Ti4+, La3+ and Eu3+ ions existence. The DRS spectra showed red shift in the band-gap transition. The experimental results of MB degradation demonstrated that the photocatalytic activity of La-Eu/TiO2 was significantly enhanced due to better separation of photogenerated electron-hole pairs.