Enhancement of photocatalytic activity of nano-scale TiO₂ particles co-doped by rare earth elements and heteropolyacids
2012
Shi, Huixian | Zhang, Tianyong | An, Taicheng | Li, Bin | Wang, Xiao
Nano-scale TiO₂ photocatalysts co-doped by rare earth ions (La³⁺, Ce³⁺) and heteropolyacids were designed and prepared by sol–gel method to probe synergistic effect on photocatalytic elimination of organic compounds, and their physicochemical properties were characterized by X-ray diffraction (XRD), specific surface area and porosity (BET and BJH), high resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), and X-ray photoelectron spectroscopy (XPS) as well as Raman spectroscopy. The photocatalytic activity of prepared catalysts was evaluated by the degradation of methylene blue (MB) in water under UV-light irradiation. The results showed that the co-doping of the rare earth ions and heteropolyacids can significantly improve the photocatalytic activity of prepared composite photocatalysts due to the efficient inhibition of the recombination of photogenerated electron–hole pairs. The enhancement mechanism of co-doping of the rare earth ions and heteropolyacids on TiO₂ is also discussed.
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