Eu2+/Gd3+-codoped nanocrystalline titania catalysts were prepared by a modified sol-gel method. Powder X-ray diffraction,Transmission electron microscopy and UV-Vis spectra analyse were carried out to characterize the catalysts with different Eu2+/Gd3+contents.The photocatalytic efficiency was evaluated by the photodegradation of methyl orange in an aqueous solution under natural light irradiation. It has been confirmed that Eu2+/Gd3+-codoped titania could be excited by natural light. The higher natural light activity is due to the codoping of Eu2+/Gd3+. An optimum synergetic effect was found for a mass ratio of Eu/TiO2 equal to 1.0% and Gd/TiO2 equal to 0.5%. The effects induced by Eu2+/Gd3+-codoped on the titania catalysts may be explained in terms of Gd3+→Eu2+ energy transfer to affect the photocatalysis activity of the titania catalysts.
A new type of photocatalysts MWCNTs/TiO2-NTs nanocomposites prepared by combining multi-walled carbon nanotube(MWCNTs) with TiO2-derived nanotubes were synthesized by a modified hydrothermal method. The SEM,XRD,UV-Vis and TG-DTG were used to characterize its property. The produced MWCNTs/TiO2-NTs nanocomposites were used as the catalysts for photo-degradation of aquatic humic substances,Their photocatalytic efficiency was evaluated by the photodegradation of humic acid in an aqueous solution under ultraviolet light irradiation. The results show MWCNTs could enhance the activity of the photocatalysts;the best degradation efficiency was obtained by using MWCNTs/TiO2-NTs nanocomposites containing 20% MWCNTs as the photo-catalyst.
