Rare Earth Modified Nanometer Tio < Sub > 2 < / Sub > Preparation And Photocatalytic Reduction Of Co < Sub > 2 < / Sub > Application Research

In recent years, rare earth doped luminescent nano-materials display a widely application prospect,such as,Laser Instruments,3D Flat-panel Displays,Accurate Light-emitting Apparatus Devices and Biological Detection Devices. However, those luminescent materials always only show a phenomenon of upconversion luminescent under the excitation of near-infrared wavelength. In this work, the up conversion luminescent phenomenon was not only studied under near-infrared wavelength exciting, but also was researched under visible light exciting, which property of it was applied to combination with TiO2, finally, the composites of them was used as catalyst in the photo-reaction. In a word, this work focused on studying the properties of these materials NaYF4:Er3+, YoO3:Er3+and Er3++Tio2.In this work, upconversion luminescent material with good response of visible light was successfully prepared by hydrothermal method, which was NaYF4:Er3+nano-materal with particles size of about80-100nm. In our studies, there were five peaks of it in the light absorption spectroscopy, which were belonged to the characteristic peaks of Er3+. NaYF4:Er3+emitted310and340nm two peaks of UV light under the excitation of500nm through fluorescence spectroscopy. However, it emitted540nm under the excitation of980nm. Finally, it was concluded that310,340and540nm peaks belonged to two-photon process with combination of Er3+energy levels.In order to study the properties of rare earth ions materials, the other of up conversion luminescent nano-composites (Y9O3:Er3+) were successfully prepared by co-precipitation method. XRD and SEM tests showed that Y2O3:Er3+was about20-30nm particles size with the cubic phase. The phenomenon of upconversion luminescent emerged under the excitation of390and500nm, the peaks of emission were240and400nm, respectively.The composites of Y2O3:Er3+/Ti02and NaYF4:Er3+/TiO2were synthesized by the method probed of ourselves, which also emitted up conversion luminescent peaks under the excitation of390and500nm.In a conclusion, the composites in this work displayed a higher activity of photo-catalytic reduction of CO2to methanol than that of un-doped TiO2.