Photocatalytic Decomposition of Methylene Blue with Lanthanum doping TiO_2 under Visible Light Irradiation

摘要

Lanthanum doped TiO_2 powders were prepared by hydrolysis of titanium tetra-n-butyl oxide and La(NO_3)_3 in solution. The resulting powders were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-Vis absorption spectroscopy. The photocatalytic activities of doped samples were evaluated by the decomposition of methylene blue under visible light irradiation. The XRD results showed that the doping of lanthanum could not only efficiently inhibit the grain growth but also suppress the phase transition of anatase to rutile. UV-Vis spectroscopy of lanthanum doping TiO_2 indicated that the absorption onset red-shifted to the visible light region. XPS results revealed that La_2O_3 had formed which could enhance the surface area. The degradation rates of methylene blue verified that the visible light photocatalytic activity of TiO_2 has been enhanced by the doping of lanthanum.