Assembly Chemistry And Photoluminesence Based On The Layered Yttrium Hydroxides

In recent years,the layered inorganic compounds have aroused great research interests because of their large specific surface and strong anisotropy unique properties.As a new type of layered material,the layered rare earth hydroxide has attracted wide attention due to its interlayer anion diversity,good morphology and structure,and various practical values.Therefore,the study of layered rare earth hydroxide is of great significance.In this paper,the layered rare earth hydroxide with layered yttrium hydroxide（LYH）as a framework and an interlayer anion of inorganic NO₃^-was assembled by the hydrothermal method,and the LYH-NO₃:Eu samples were prepared by doping different concentrations of red-emitting Eu³⁺.After heat treatment to the sample,the Y₂O₃:Eu phosphor was achieved.Moreover,the layered rare earth hydroxide with LYH as a framework and an interlayer anion as an organic dodecylsulfonate anion（DS^-）,rare earth Ce³⁺,Tb³⁺co-doped sample（abbreviated as LYH-DS:Ce,Tb）and Ce³⁺,Eu³⁺co-doped sample（abbreviated as LYH-DS:Ce,Eu）were also assembled.The scaning electron microscopy,energy dispersive spectroscopy,X-ray diffraction patterns,thermogravimetry,photoluminescence,color coordinate,and fluorescence decay curve were used to characterize their morphology,elements,structure,luminescent performance and fluorescent lifetime.The heat treatment of the LYH-NO₃:Eu into Y₂O₃:Eu phosphor retains the lamellar structure,and the relative fluorescence intensity of Y₂O₃:Eu phosphor is compared with those prepared by direct hydrothermal and high temperature solid state reaction,which is 1.5 and 3 times,respectively.Furthermore,the luminescence is greatly improved in comparison with that of LYH-NO₃:Eu.This may provide a new approach for synthesizing red phosphor with superior luminescence performance.In LYH-DS:Ce,Tb and LYH-DS:Ce,Eu samples,the energy transfer from Ce³⁺→Tb³⁺,and Ce³⁺→Eu³⁺is observed by changing the doping amount of Tb³⁺and Eu³⁺,and realize the color adjustment from blue to shallow blue and green light,and from blue to shallow blue and white light.Therefore,the color-tunable layered sample can be prepared by adjusting the concentration of rare earth ions,and the type of doping,which is possible to applyin the optoelectronic fields.