Preparation And Properties Of Persistent Luminescence Nanomaterials With Tunable Emission Wavelength

A material that has persistent luminescence is a special kind of material that absorbs and stores the energy of external ultraviolet or visible light.When the irradiation stops for a period of time,under certain conditions the stored energy will still be released in the form of light slowly.Ion-doped persistent luminescent material is an important photoluminescence material,which has the advantages of simple preparation process,stable luminescent properties and strong repeatability.Moreover,the luminescent position can be regulated by doping or co-doping different central ions,so as to prepare luminescent materials with different luminescent properties of different substrates and doped ions.It is also one of the important methods to prepare luminescent materials.Persistent luminescent materials have been widely used in biomedicine,sensor detection,architectural decoration,information storage,anti-counterfeiting encryption,security emergency instructions and so on.In recent years,persistent luminescence nanomaterials with tunable emission wavelengths have become a new research topic because of their special optical properties and applications in different fields.Two kinds of persistent luminescent materials with tunable emission wavelength have been prepared by using different substrates and doped ions.The main research contents and results of this thesis are as follows:（1）Zn₂Si_xO₄:Ga_0.01（ZSO:Ga）persistent luminescence nanomaterials with dual wavelength were successfully prepared by hydrothermal and calcination method with Zn（NO₃）₂、SiCl₄、Ga（NO₃）₃ as raw materials.The persistent luminescence properties of ZSO:Ga were optimized by adjusting the p H and Sicontent in the precursor solution.The compositions of the ZSO:Ga were determined by XRD and TEM,and the luminescence properties of the ZSO:Ga were studied by phosphorescence emission spectrum and excitation spectra.The afterglow properties of the ZSO:Ga were studied by means of the afterglow decay spectrum and NIR afterglow images.Finally,the optimum synthesis conditions were p H=7 and Sicontent of 1.1.Under 254 nm UV excitation,ZSO:Ga can produce light in the 300～600 nm band centered at 417 nm and 650～850 nm band centered at 770 nm.And the ZSO:Ga has good afterglow performance,can be observed a 9days of afterglow in the near-infrared region.We have successfully constructed a high level of multi-mode dynamic anti-counterfeiting model by using ZSO:Ga dual-wavelength afterglow luminescence performance.The material of the anti-counterfeiting is easy to synthesize and operate,and it has great potential in practical application.（2）Zn₂Sn_xO₄:0.3%Cr³⁺（ZSO:Cr）persistent luminescence nanomaterials have been successfully prepared by hydrothermal and calcination method with Zn（NO₃）₂、SnCl₄、Cr（NO₃）₃ as raw materials.The persistent luminescence properties of ZSO:Cr were optimized by adjusting the p H and Sncontent in the precursor solution.The compositions of the ZSO:Cr were determined by XRD and TEM,and the luminescence properties of the ZSO:Cr were studied by phosphorescence emission spectrum and excitation spectra.The afterglow properties of the ZSO:Cr were studied by means of the afterglow decay spectru and NIR afterglow images.Finally,the optimum synthesis conditions were p H=12 and Sncontent of 1.2.ZSO:Cr can produce 700～1000 nm light with a center of 790 nm under310 nm UV excitation.And the afterglow time reaches about 9 days.The emission band overlaps with the absorption of the organic dye IR-1061,so F（?）rster resonance energy transfer（FRET）can occur when persistent luminescent materials and organic dyes are compounded.The composite ZSO-IR has emission at 1250 nm.The emission wavelength can penetrate deeper tissues in organism,so it can be used as a fluorescence probe and has a wide application prospect in the field of biomedical imaging.