CN108130083B

CN108130083B - Red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material and preparation method thereof

Info

Publication number: CN108130083B
Application number: CN201711469191.6A
Authority: CN
Inventors: 徐展; 赵景泰
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2017-12-29
Filing date: 2017-12-29
Publication date: 2021-06-04
Anticipated expiration: 2037-12-29
Also published as: CN108130083A

Abstract

The invention provides a rare earth oxyhydroxide luminescent material with adjustable red and green discoloration and a preparation method thereof. Taking the host as Y(OH) _m F _3‑m , by doping the crystal lattice with different proportions of rare earth luminescent ions Eu ³⁺ , Tb ³⁺ , the luminescence can be adjusted in the 500nm green and 650nm red bands. Using the precursor material Y ₂ (OH) ₅ NO ₃ ·nH ₂ O:x%Eu ³⁺ ,y%Tb ³⁺ with interlayer anion exchange properties, Y(OH) _mF was obtained by water bath fluorination at 80℃ _3‑m : x% Eu ³⁺ , y% Tb ³⁺ rare earth oxyhydroxide luminescent material. The material has excellent red-green color-changing luminescence properties, can be used in fields such as LED phosphors, and has a simple preparation method, low energy consumption, and good economic value.

Description

Red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material and preparation method thereof

Technical Field

The invention relates to a luminescent material and a preparation method thereof, in particular to a multicolor luminescent material and a synthesis process method thereof, which are applied to the technical field of inorganic luminescent functional materials and preparation thereof.

Background

The rare earth element has a unique 4f electronic structure, and because of shielding of outer layer electrons, the rare earth element is less influenced by an external electromagnetic field, so that the compound containing the rare earth shows a plurality of unique physical and chemical properties, is widely applied to the fields of light, electricity, magnetism and the like, and is known as a treasure house of new materials. In China, a very rich rare earth resource exists, and how to more effectively utilize the rare earth resource and develop a rare earth functional material to serve national production and life, national safety and the like becomes an important subject of China. In the development and utilization of rare earth functional materials, rare earth luminescent materials are particularly attractive, and are widely applied to the fields of biological fluorescence detection, laser, LED and the like. The development of the rare earth luminescent functional material which has higher luminescent efficiency and longer service life and meets the requirements of various application occasions has very important significance.

At present, most of substrates used by rare earth luminescent materials are oxide materials, and the rare earth luminescent materials are simple to prepare and have excellent performance. Compared with oxides, the inorganic fluoride has the characteristics of low phonon energy, strong ionicity, small electron cloud expansion effect and the like. As a luminescent material substrate, the material has the advantages of high refractive index, high near ultraviolet, visible and near infrared light transmittance, high luminous efficiency and the like, thereby attracting the wide attention of researchers in foreign countries. For example, domestic Liugui Xixia et al successfully prepared rod-shaped LaF by liquid phase method₃：Eu³⁺A fluorescent material; the research group of Haase in Germany, P.N.Prasad in America and the like synthesizes monodisperse nano NaYF₄The fluorescent material is found to have good up-conversion luminescence performance, and can be applied to the fields of biological fluorescence detection and the like. The development of rare earth fluoride luminescent materials with excellent performance and special luminescent performance has become a research hotspot at home and abroad.

However, the rare earth fluoride material is usually synthesized by solvothermal and pyrolysis methods, and has the following disadvantages, which restrict the large-scale application of the fluoride luminescent material in practical production and life:

1. the required conditions are harsh, and high temperature and high pressure not only require a large amount of energy consumption, but also bring about a series of potential safety hazards;

2. the used solvent is usually an organic solvent, so that organic groups are attached to the surface of the synthesized fluoride material, and the luminous efficiency of the material is remarkably low;

3. the synthesis and growth of the material are autonomous processes, and the structural morphology is not easy to control. Therefore, it becomes important to search for a more suitable preparation method of rare earth fluoride.

RE₂(OH)₅NO₃·nH₂O, a layered rare earth hydroxide (LRHs), wherein RE³⁺Is rare earth ion, and n is the number of crystal water. LRHs are composed of a main layer with positive charges and interlayer anions with negative charges, the main layer is connected with the interlayer anions through electrostatic force, the acting force is weak, and the interlayer anions can be replaced by other anions under certain conditions, so that the LRHs have unique anion exchange characteristics. It can undergo a topological phase change after being exchanged by certain anions and be converted into other phases. By utilizing the characteristics, the LRHs can serve as a precursor in material synthesis, so that more and more researchers begin to explore a series of functional materials synthesized by the LRHs. Meanwhile, rare earth ions in the main layer of the LRHs have rich optical characteristics, so that the synthesis of the luminescent material by utilizing the rare earth ions becomes an important application of the luminescent material.

Rare earth oxyhydrogen fluoride is one kind of fluoride, and is a luminescent material with excellent performance, and a research group synthesizes a single-color luminescent material as a matrix, but the synthesis of a multicolor luminescent material is not reported at present. And at present, rare earth salt compounds and fluorides are synthesized under hydrothermal conditions, the fluorination process time is long, and the morphology regulation is difficult.

Disclosure of Invention

In order to solve the problems of the prior art, the invention aims to overcome the defects of the prior art and provide a red-green color-changing adjustable rare earth oxyhydrogen fluoride luminescent material and a preparation method thereof. The invention utilizes a hydrothermal method to synthesize rare earth layered hydroxide as a precursor, and rare earth luminescent ion Eu with certain concentration is doped in the process³⁺And Tb³⁺And then, fluoride is used for water bath fluorination at a certain temperature to prepare the red-green color-changing adjustable rare earth oxyhydrogen fluoride luminescent material.

In order to achieve the purpose, the invention adopts the following technical scheme:

a red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, and the crystal structure of the composite rare earth oxy-hydrogen fluoride is doped with rare earth luminescent ions Eu³⁺And Tb³⁺The light emission can be adjusted in the red and green light band of 620-500 nm.

As the preferred technical scheme of the invention, the rare earth oxy-hydrogen fluoride luminescent material crystal with adjustable red and green discoloration is in a hexagonal crystal structure and belongs to a p 63/m space group, and Y in a crystal lattice³⁺With OH^-And F^-Constituting eight or nine coordinates, a part of Y³⁺Is rare earth luminous ion Eu³⁺And Tb³⁺The lattice is substitutional.

As the preferable technical scheme of the invention, the chemical general formula of the red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material is Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺M is more than 0 and less than 3 in the chemical general formula; x is more than 0<100；0＜y<100；x+y<100, respectively; doped Eu³⁺And Tb³⁺Partial substitution matrix Y (OH) of rare earth element ion_mF_3-mY in (1)³⁺Wherein x% or y% is the mass percentage concentration of the doped ions in the composite rare earth oxyhydrogen fluoride, and x% is Eu³⁺Y% is Tb³⁺The doping amount of (a).

As a further preferable technical scheme of the invention, the chemical general formula of the red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material is Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺M in the chemical general formula is more than 0 and less than or equal to 2.02; x is more than 0 and less than or equal to 5; y is more than or equal to 1.25 and less than or equal to 40.

The invention relates to a preparation method of a red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material, which adopts Y₂(OH)₅NO₃·nH₂O:x％Eu³⁺,y％Tb³⁺Synthesis of Y (OH) by fluorination as precursor Material under Water bath conditions_mF_3-m:x％Eu³⁺,y％Tb³⁺Thereby obtaining the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green discoloration, wherein in the chemical formula of the precursor material, n is the number of crystal water in the chemical formula.

As the preferred technical scheme of the invention, the preparation method of the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green discoloration comprises the following steps:

a. preparing a solution required in the preparation process:

a-1. mixing Y (NO)₃)₃·6H₂Dissolving O in deionized water to prepare Y (NO)₃)₃An aqueous solution;

a-2. adding Eu (NO)₃)₃·6H₂Dissolving O in deionized water to prepare Eu (NO)₃)₃An aqueous solution;

a-3. mixing Tb (NO)₃)₃·6H₂Dissolving O in deionized water to prepare Tb (NO)₃)₃An aqueous solution;

a-4, adding deionized water into a concentrated ammonia water solution with the mass concentration of 25% to prepare NH with the pH value not lower than 12₄An aqueous OH solution as an alkaline conditioning solution;

a-5, adding deionized water into concentrated nitric acid solution with mass concentration of 68% to prepare HNO with pH value not more than 1₃An aqueous solution as an acidic conditioning solution;

in step a, Y (NO) formulated in step a-1 is preferred₃)₃Aqueous solution, Eu (NO) prepared in step a-2₃)₃Aqueous solution and Tb (NO) formulated in step a-3₃)₃The molar concentration of the rare earth ions in the aqueous solution is 1 mol/L;

b. preparation of Y₂(OH)₅NO₃·nH₂O:x％Eu³⁺,y％Tb³⁺Precursor material:

b-1. Y (NO) formulated in step a at room temperature₃)₃Aqueous solution, Eu (NO)₃)₃Aqueous solution and Tb (NO)₃)₃Mixing the aqueous solution according to a certain stoichiometric ratio, adding deionized water, and stirring and mixing uniformly to obtain a rare earth ion mixed solution; as a preferred technical scheme of the invention, when preparing the rare earth ion mixed liquid, the mixing range of a certain stoichiometric ratio is as follows: eu (Eu)³⁺，Tb³⁺The content of the compound is as required to finally synthesize Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺Adding the doping ratio of x and y in (1); as a further preferable technical proposal of the invention, when preparing the rare earth ion mixed liquor, the certain stoichiometric ratio is according to Y in the prepared rare earth ion mixed liquor³⁺、Eu³⁺And Tb³⁺The molar ratio of (550-937.5) to (50) (12.5-400) of Y (NO)₃)₃Aqueous solution, Eu (NO)₃)₃Aqueous solution and Tb (NO)₃)₃Mixing the aqueous solutionCombining; as a preferred technical scheme of the invention, when preparing the rare earth ion mixed solution, the addition amount of a certain amount of deionized water is as follows: adding deionized water to obtain Y in the mixed solution³⁺、Eu³⁺And Tb³⁺The concentration of the total rare earth cation reaches the required amount of 0.067 mol/L;

b-2, adding a certain amount of NH into the rare earth ion mixed liquor prepared in the step b-1₄NO₃Stirring in water bath at not higher than 80 deg.C to make NH₄NO₃Completely dissolving to obtain a rare earth hydroxide mixed solution, slowly dropwise adding the alkaline regulating solution prepared in the step a into the rare earth hydroxide mixed solution until the pH value of the rare earth hydroxide mixed solution is 6.5-7.5, continuously stirring the rare earth hydroxide mixed solution for reaction for at least 1h to carry out hydrothermal reaction, after the hydrothermal reaction is finished, repeatedly washing and centrifuging the reaction product by using deionized water and absolute ethyl alcohol for at least 3 times, then drying at normal pressure at the temperature of not lower than 60 ℃, and collecting to obtain rare earth layered hydroxide Y₂(OH)₅NO₃·nH₂O:x％Eu³⁺,y％Tb³⁺As precursor material for standby; in the preparation of Y₂(OH)₅NO₃·nH₂O:x％Eu³⁺,y％Tb³⁺As precursor material, NH preferably used₄NO₃The amount of (A) is an excess ratio; as a preferred technical solution of the present invention, the certain amount of NH₄NO₃Is referred to as NH₄NO₃The amount of substance is Y in the mixed solution of rare earth hydroxide³⁺、Eu³⁺And Tb³⁺15/2 of total rare earth cation species;

c. preparation of Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺：

c-1, adopting fluorine-containing inorganic salt as fluorinating agent, mixing and proportioning the fluorine-containing inorganic salt and the Y prepared in the step b according to a certain stoichiometric ratio at room temperature₂(OH)₅NO₃·nH₂O:x％Eu³⁺,y％Tb³⁺The precursor materials are mixed evenly and addedDeionized water is continuously stirred until the fluorine-containing inorganic salt is completely dissolved to obtain a reactant mixed liquid system; as a preferable embodiment of the present invention, in the preparation of the reactant mixed liquid system, the fluorine-containing inorganic salt and Y are used₂(OH)₅NO₃·nH₂O:x％Eu³⁺,y％Tb³⁺The precursor material is F in fluoride in a certain stoichiometric ratio^-And Y₂(OH)₅NO₃·nH₂O:x％Eu³⁺,y％Tb³⁺The mass ratio of (A) to (B) is 0.98: 0.5; in the preparation of the reactant mixture liquid system, NH is preferably used as the fluorine-containing inorganic salt₄F. Any one simple substance salt or any mixture of multiple simple substance salts of NaF and KF; as a preferred technical scheme of the present invention, when preparing a reactant mixed solution system, the addition amount of a certain amount of deionized water is: adding deionized water to obtain Y in the mixed solution³⁺、Eu³⁺And Tb³⁺The concentration of the total rare earth cation reaches the required amount of 0.067 mol/L; as a preferred technical scheme of the invention, the certain stoichiometric ratio is as follows: f in fluoride^-And Y₂(OH)₅NO₃·nH₂O:x％Eu³⁺,y％Tb³⁺The preferred value of the mass ratio of (b) is 1: 1;

c-2, slowly dripping the acidic regulating solution prepared in the step a into the reactant mixed liquid system prepared in the step c-1 until the pH value of the reactant mixed liquid system is 8.0-9.0, stirring at the temperature of no higher than 80 ℃, carrying out water bath fluorination reaction for at least 3h, washing with deionized water and absolute ethyl alcohol at the end of the reaction, centrifuging for at least 3 times respectively, and then carrying out normal pressure drying at the temperature of no higher than 60 ℃ to obtain Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺A color-changing adjustable luminescent material.

The prepared rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green discoloration can be adjusted between the red light of 650nm and the green light of 500nm in wavelength range; the chemical formula is Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺Wherein m is more than 0 and less than 3; x is more than or equal to 0<100；0≤y<100；x+y<100(ii) a Is hexagonal phase crystal structure and belongs to p 63/m space group. Y in the host lattice³⁺With OH^-And F^-Form eight or nine coordination, and part of the coordination is covered by rare earth luminescent ion Eu³⁺And Tb³⁺The lattice is substitutional. The invention prepares the red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material, utilizes a hydrothermal method to synthesize rare earth layered hydroxide as a precursor, and dopes rare earth luminescent ion Eu with certain concentration in the process³⁺And Tb³⁺And then, fluoride is used for water bath fluorination at a certain temperature to prepare the red-green color-changing adjustable rare earth oxyhydrogen fluoride luminescent material.

Compared with the prior art, the invention has the following obvious and prominent substantive characteristics and remarkable advantages:

1. y (OH) prepared by the invention_mF_3-m:x％Eu³⁺,y％Tb³⁺The material has the advantages of a fluoride material, realizes the characteristic of red-green color change adjustability by changing the relative proportion of doped Eu and Tb, and can be used as fluorescent powder required by an LED and the like;

2. the invention provides Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺The preparation method of the material is a two-step water bath fluorination method, so that the long-time high-temperature and high-pressure condition required by the traditional fluoride material preparation is avoided; the preparation method has the advantages of simple preparation process, mild conditions, short preparation period, suitability for large-scale preparation, low energy consumption and environmental friendliness;

3. the invention Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺The preparation method is a water bath condition, so that organic groups are not attached to the surface of the obtained material, the application occasion is widened, and the luminous efficiency is improved;

4. the rare earth oxyhydrogen fluoride luminescent material prepared by the invention has excellent red-green allochroic luminescent property, can be used in the fields of LED fluorescent powder and the like, and has the advantages of simple and convenient preparation method, low energy consumption and better economic value.

Drawings

FIG. 1 shows Y (OH) prepared in examples one to six of the present invention_mF_3-m:x％Eu³⁺,y％Tb³⁺Comparing the X-ray diffraction (XRD) patterns of the two.

FIG. 2 is Y (OH) prepared according to example III of the present invention₂.02F_0.98:5％Eu³⁺,5％Tb³⁺Scanning Electron Microscope (SEM) images of (a).

FIG. 3 is Y (OH) prepared according to example III of the present invention_2.02F_0.98:5％Eu³⁺,5％Tb³⁺Fourier-infrared (FT-IR) spectra of (a).

FIG. 4 shows Y (OH) prepared in examples one to six of the present invention_mF_3-m:x％Eu³⁺,y％Tb³⁺Emission spectra (PL) contrast at an excitation wavelength of 380 nm.

FIG. 5 is Y (OH) prepared by examples one to six of the present invention_mF_3-m:x％Eu³⁺,y％Tb³⁺And drawing the obtained color coordinate graph of the rare earth oxyhydrogen fluoride luminescent material.

Detailed Description

The above-described scheme is further illustrated below with reference to specific embodiments, which are detailed below:

the first embodiment is as follows:

in this embodiment, a red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, which has a chemical formula of Y (OH)_2.02F_0.98:5％Eu³⁺,1.25％Tb³⁺The crystal structure of which is doped with rare earth luminous ion Eu³⁺And Tb³⁺，Eu³⁺And Tb³⁺Partial displacement of rare earth ions by Y in a matrix³⁺Wherein 5 percent or 1.25 percent is the mass percentage concentration of the doping ions in the composite rare earth hydroxide fluoride, Eu³⁺Doping amount of (5%), Tb³⁺The doping amount of (A) is 1.25%. The light emitting energy of the rare earth oxyhydrogen fluoride luminescent material with adjustable red and green color change can be adjusted in a red and green light wave band of 620-500 nm.

The preparation method of the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green discoloration comprises the following steps:

a. preparing a solution required in the preparation process:

a-1. mixing Y (NO)₃)₃·6H₂Dissolving O in deionized water to prepare Y (NO) with the concentration of 1mol/L₃)₃An aqueous solution;

a-2. adding Eu (NO)₃)₃·6H₂Dissolving O in deionized water to prepare Eu (NO) with concentration of 1mol/L₃)₃An aqueous solution;

a-3. mixing Tb (NO)₃)₃·6H₂Dissolving O in deionized water to prepare Tb (NO) with concentration of 1mol/L₃)₃An aqueous solution;

a-4, adding deionized water into a concentrated ammonia water solution with the mass concentration of 25% to prepare NH with the pH value of 12₄An aqueous OH solution as an alkaline conditioning solution;

a-5, adding deionized water into concentrated nitric acid solution with mass concentration of 68% to prepare HNO with pH value of 1₃An aqueous solution as an acidic conditioning solution;

b. preparation of Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,1.25％Tb³⁺Precursor material:

b-1. Y (NO) formulated in step a at room temperature₃)₃Aqueous solution, Eu (NO)₃)₃Aqueous solution and Tb (NO)₃)₃937.5 mu L, 50 mu L and 12.5 mu L of the aqueous solution are mixed, 60mL of deionized water is added, and the mixture is stirred and mixed uniformly to obtain a rare earth ion mixed solution;

b-2, adding 150mmol of NH into the rare earth ion mixed solution prepared in the step b-1₄NO₃Stirring in water bath at 80 deg.C to make NH₄NO₃Completely dissolving to obtain a rare earth hydroxide mixed solution, slowly dropwise adding the alkaline regulating solution prepared in the step a into the rare earth hydroxide mixed solution until the pH value of the rare earth hydroxide mixed solution is 7, continuously stirring and reacting the rare earth hydroxide mixed solution for 1h to perform hydrothermal reaction, repeatedly washing and centrifuging the reaction product for 3 times by using deionized water and absolute ethyl alcohol after the hydrothermal reaction is finished, and then performing centrifugal separation at 60 DEG CDrying at normal pressure, and collecting to obtain rare earth layered hydroxide Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,1.25％Tb³⁺As precursor material for standby;

c. preparation of Y (OH)_2.02F_0.98:5％Eu³⁺,1.25％Tb³⁺：

c-1, adopting fluorine-containing inorganic salt NH₄F is used as a fluorinating agent, 2mmol of NH is mixed according to a certain stoichiometric ratio at room temperature₄F and 0.2g of Y prepared in said step b₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,1.25％Tb³⁺The precursor materials are mixed evenly, 30mL of deionized water is added, and the mixture is stirred continuously until NH is achieved₄F is completely dissolved to obtain a reactant mixed liquid system;

c-2, slowly dripping the acidic regulating solution prepared in the step a into the reactant mixed solution system prepared in the step c-1 until the pH value of the reactant mixed solution system is 8.0, stirring at the temperature of 80 ℃, carrying out water bath fluorination reaction for 3 hours, washing with deionized water and absolute ethyl alcohol after the reaction is finished, centrifuging for 3 times respectively, and then drying at the temperature of 60 ℃ under normal pressure to obtain Y (OH)_2.02F_0.98:5％Eu³⁺,1.25％Tb³⁺A color-changing adjustable luminescent material.

This example uses Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,1.25％Tb³⁺Synthesis of Y (OH) by fluorination as precursor Material under Water bath conditions_2.02F_0.98:5％Eu³⁺,1.25％Tb³⁺Thereby obtaining the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green color change. In the embodiment, the anion exchange characteristic of the LRHs is utilized to fluorinate the LRHs, so that the preparation of the rare earth hydroxide fluoride is a better synthetic route. The red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material prepared by the embodiment takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, and a crystal structure of the composite rare earth oxy-hydrogen fluoride is doped with rare earth luminescent ions Eu³⁺And Tb³⁺The light emission can be adjusted in the red and green light band of 620-500 nm. The preparation method has the advantages of simple preparation process, mild conditions, short preparation period, suitability for mass preparation, low energy consumption and environmental friendliness. The preparation method is a water bath condition, so that organic groups are not attached to the surface of the obtained material, the application range is widened, and the luminous efficiency is improved.

Example two:

this embodiment is substantially the same as the first embodiment, and is characterized in that:

in this embodiment, a red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, which has a chemical formula of Y (OH)_2.02F_0.98:5％Eu³⁺,2.5％Tb³⁺The crystal structure of which is doped with rare earth luminous ion Eu³⁺And Tb³⁺，Eu³⁺And Tb³⁺Partial displacement of rare earth ions by Y in a matrix³⁺Wherein 5 percent or 2.5 percent is the mass percentage concentration of the doping ions in the composite rare earth hydroxide fluoride, Eu³⁺Doping amount of (5%), Tb³⁺The doping amount of (A) is 2.5%. The light emitting energy of the rare earth oxyhydrogen fluoride luminescent material with adjustable red and green color change can be adjusted in a red and green light wave band of 620-500 nm.

a. preparing a solution required in the preparation process: the step is the same as the first embodiment;

b. preparation of Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,2.5％Tb³⁺Precursor material:

b-1. Y (NO) formulated in step a at room temperature₃)₃Aqueous solution, Eu (NO)₃)₃Aqueous solution and Tb (NO)₃)₃Mixing 925 mu L, 50 mu L and 25 mu L of the aqueous solution, adding 60mL of deionized water, and uniformly stirring and mixing to obtain a rare earth ion mixed solution;

b-2, adding 150mmol of NH into the rare earth ion mixed solution prepared in the step b-1₄NO₃Stirring in water bath at 80 deg.C to make NH₄NO₃Completely dissolving to obtain a rare earth hydroxide mixed solution, slowly dropwise adding the alkaline regulating solution prepared in the step a into the rare earth hydroxide mixed solution until the pH value of the rare earth hydroxide mixed solution is 7, continuously stirring and reacting the rare earth hydroxide mixed solution for 1h to perform hydrothermal reaction, repeatedly washing and centrifuging reaction products for 3 times by using deionized water and absolute ethyl alcohol after the hydrothermal reaction is finished, drying at the temperature of 60 ℃ under normal pressure, and collecting to obtain a rare earth layered hydroxide Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,2.5％Tb³⁺As precursor material for standby;

c. preparation of Y (OH)_2.02F_0.98:5％Eu³⁺,2.5％Tb³⁺：

c-1, adopting fluorine-containing inorganic salt NH₄F is used as a fluorinating agent, 2mmol of NH is mixed according to a certain stoichiometric ratio at room temperature₄F and 0.2g of Y prepared in said step b₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,2.5％Tb³⁺The precursor materials are mixed evenly, 30mL of deionized water is added, and the mixture is stirred continuously until NH is achieved₄F is completely dissolved to obtain a reactant mixed liquid system;

c-2, slowly dripping the acidic regulating solution prepared in the step a into the reactant mixed solution system prepared in the step c-1 until the pH value of the reactant mixed solution system is 8.0, stirring at the temperature of 80 ℃, carrying out water bath fluorination reaction for 3 hours, washing with deionized water and absolute ethyl alcohol after the reaction is finished, centrifuging for 3 times respectively, and then drying at the temperature of 60 ℃ under normal pressure to obtain Y (OH)_2.02F_0.98:5％Eu³⁺,2.5％Tb³⁺A color-changing adjustable luminescent material.

This example uses Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,2.5％Tb³⁺As precursor materialSynthesis of Y (OH) by fluorination under aqueous bath conditions_2.02F_0.98:5％Eu³⁺,2.5％Tb³⁺Thereby obtaining the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green color change. In the embodiment, the anion exchange characteristic of the LRHs is utilized to fluorinate the LRHs, so that the preparation of the rare earth hydroxide fluoride is a better synthetic route. The red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material prepared by the embodiment takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, and a crystal structure of the composite rare earth oxy-hydrogen fluoride is doped with rare earth luminescent ions Eu³⁺And Tb³⁺The light emission can be adjusted in the red and green light band of 620-500 nm. The preparation method has the advantages of simple preparation process, mild conditions, short preparation period, suitability for mass preparation, low energy consumption and environmental friendliness. The preparation method is a water bath condition, so that organic groups are not attached to the surface of the obtained material, the application range is widened, and the luminous efficiency is improved.

Example three:

this embodiment is substantially the same as the previous embodiment, and is characterized in that:

in this embodiment, a red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, which has a chemical formula of Y (OH)_2.02F_0.98:5％Eu³⁺,5％Tb³⁺The crystal structure of which is doped with rare earth luminous ion Eu³⁺And Tb³⁺，Eu³⁺And Tb³⁺Partial displacement of rare earth ions by Y in a matrix³⁺Wherein 5 percent or 5 percent is the mass percentage concentration of the doping ions in the composite rare earth hydroxide fluoride, Eu³⁺Doping amount of (5%), Tb³⁺The doping amount of (2) is 5%. The light emitting energy of the rare earth oxyhydrogen fluoride luminescent material with adjustable red and green color change can be adjusted in a red and green light wave band of 620-500 nm.

b. preparation of Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,5％Tb³⁺Precursor material:

b-1. Y (NO) formulated in step a at room temperature₃)₃Aqueous solution, Eu (NO)₃)₃Aqueous solution and Tb (NO)₃)₃Mixing 900 mu L, 50 mu L and 50 mu L of the aqueous solution, adding 60mL of deionized water, and uniformly stirring and mixing to obtain a rare earth ion mixed solution;

b-2, adding 150mmol of NH into the rare earth ion mixed solution prepared in the step b-1₄NO₃Stirring in water bath at 80 deg.C to make NH₄NO₃Completely dissolving to obtain a rare earth hydroxide mixed solution, slowly dropwise adding the alkaline regulating solution prepared in the step a into the rare earth hydroxide mixed solution until the pH value of the rare earth hydroxide mixed solution is 7, continuously stirring and reacting the rare earth hydroxide mixed solution for 1h to perform hydrothermal reaction, repeatedly washing and centrifuging reaction products for 3 times by using deionized water and absolute ethyl alcohol after the hydrothermal reaction is finished, drying at the temperature of 60 ℃ under normal pressure, and collecting to obtain a rare earth layered hydroxide Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,5％Tb³⁺As precursor material for standby;

c. preparation of Y (OH)_2.02F_0.98:5％Eu³⁺,5％Tb³⁺：

c-1, adopting fluorine-containing inorganic salt NH₄F is used as a fluorinating agent, 2mmol of NH is mixed according to a certain stoichiometric ratio at room temperature₄F and 0.2g of Y prepared in said step b₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,5％Tb³⁺The precursor materials are mixed evenly, 30mL of deionized water is added, and the mixture is stirred continuously until NH is achieved₄F is completely dissolved to obtain a reactant mixed liquid system;

c-2, slowly dripping into the reactant mixed liquid system prepared in the step c-1Adding the acidic regulating solution prepared in the step a until the pH value of a reactant mixed solution system is 8.0, stirring at the temperature of 80 ℃, carrying out water bath fluorination reaction for 3 hours, washing with deionized water and absolute ethyl alcohol after the reaction is finished, centrifuging for 3 times respectively, and then drying at the temperature of 60 ℃ under normal pressure to obtain Y (OH)_2.02F_0.98:5％Eu³⁺,5％Tb³⁺A color-changing adjustable luminescent material.

This example uses Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,5％Tb³⁺Synthesis of Y (OH) by fluorination as precursor Material under Water bath conditions_2.02F_0.98:5％Eu³⁺,5％Tb³⁺Thereby obtaining the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green color change. In the embodiment, the anion exchange characteristic of the LRHs is utilized to fluorinate the LRHs, so that the preparation of the rare earth hydroxide fluoride is a better synthetic route. The red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material prepared by the embodiment takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, and a crystal structure of the composite rare earth oxy-hydrogen fluoride is doped with rare earth luminescent ions Eu³⁺And Tb³⁺The light emission can be adjusted in the red and green light band of 620-500 nm. The preparation method has the advantages of simple preparation process, mild conditions, short preparation period, suitability for mass preparation, low energy consumption and environmental friendliness. The preparation method is a water bath condition, so that organic groups are not attached to the surface of the obtained material, the application range is widened, and the luminous efficiency is improved.

Example four:

in this embodiment, a red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, which has a chemical formula of Y (OH)_2.02F_0.98:5％Eu³⁺,10％Tb³⁺The crystal structure of which is doped with rare earth luminous ion Eu³⁺And Tb³⁺，Eu³⁺And Tb³⁺Partial displacement of rare earth ions by Y in a matrix³⁺Wherein 5 percent or 10 percent is the mass percentage concentration of the doping ions in the composite rare earth hydroxide fluoride, Eu³⁺Doping amount of (5%), Tb³⁺The doping amount of (A) is 10%. The light emitting energy of the rare earth oxyhydrogen fluoride luminescent material with adjustable red and green color change can be adjusted in a red and green light wave band of 620-500 nm.

b. preparation of Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,10％Tb³⁺Precursor material:

b-1. Y (NO) formulated in step a at room temperature₃)₃Aqueous solution, Eu (NO)₃)₃Aqueous solution and Tb (NO)₃)₃Mixing 850 mu L, 50 mu L and 100 mu L of the aqueous solution, adding 60mL of deionized water, and uniformly stirring and mixing to obtain a rare earth ion mixed solution;

b-2, adding 150mmol of NH into the rare earth ion mixed solution prepared in the step b-1₄NO₃Stirring in water bath at 80 deg.C to make NH₄NO₃Completely dissolving to obtain a rare earth hydroxide mixed solution, slowly dropwise adding the alkaline regulating solution prepared in the step a into the rare earth hydroxide mixed solution until the pH value of the rare earth hydroxide mixed solution is 7, continuously stirring and reacting the rare earth hydroxide mixed solution for 1h to perform hydrothermal reaction, repeatedly washing and centrifuging reaction products for 3 times by using deionized water and absolute ethyl alcohol after the hydrothermal reaction is finished, drying at the temperature of 60 ℃ under normal pressure, and collecting to obtain a rare earth layered hydroxide Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,10％Tb³⁺As precursor material for standby;

c. preparation of Y (OH)_2.02F_0.98:5％Eu³⁺,10％Tb³⁺：

c-1, adopting fluorine-containing inorganic salt NH₄F is used as a fluorinating agent, 2mmol of NH is mixed according to a certain stoichiometric ratio at room temperature₄F and 0.2g of Y prepared in said step b₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,10％Tb³⁺The precursor materials are mixed evenly, 30mL of deionized water is added, and the mixture is stirred continuously until NH is achieved₄F is completely dissolved to obtain a reactant mixed liquid system;

c-2, slowly dripping the acidic regulating solution prepared in the step a into the reactant mixed solution system prepared in the step c-1 until the pH value of the reactant mixed solution system is 8.0, stirring at the temperature of 80 ℃, carrying out water bath fluorination reaction for 3 hours, washing with deionized water and absolute ethyl alcohol after the reaction is finished, centrifuging for 3 times respectively, and then drying at the temperature of 60 ℃ under normal pressure to obtain Y (OH)_2.02F_0.98:5％Eu³⁺,10％Tb³⁺A color-changing adjustable luminescent material.

This example uses Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,10％Tb³⁺Synthesis of Y (OH) by fluorination as precursor Material under Water bath conditions_2.02F_0.98:5％Eu³⁺,10％Tb³⁺Thereby obtaining the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green color change. In the embodiment, the anion exchange characteristic of the LRHs is utilized to fluorinate the LRHs, so that the preparation of the rare earth hydroxide fluoride is a better synthetic route. The red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material prepared by the embodiment takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, and a crystal structure of the composite rare earth oxy-hydrogen fluoride is doped with rare earth luminescent ions Eu³⁺And Tb³⁺The light emission can be adjusted in the red and green light band of 620-500 nm. The preparation method has the advantages of simple preparation process, mild conditions, short preparation period, suitability for mass preparation, low energy consumption and environmental friendliness. The preparation method is a water bath condition, so that organic groups are not attached to the surface of the obtained material, the application range is widened, and the luminous efficiency is improved.

Example five:

in this embodiment, a red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, which has a chemical formula of Y (OH)_2.02F_0.98:5％Eu³⁺,20％Tb³⁺The crystal structure of which is doped with rare earth luminous ion Eu³⁺And Tb³⁺，Eu³⁺And Tb³⁺Partial displacement of rare earth ions by Y in a matrix³⁺Wherein 5 percent or 20 percent is the mass percentage concentration of doping ions in the composite rare earth hydroxide fluoride, Eu³⁺Doping amount of (5%), Tb³⁺The doping amount of (A) is 20%. The light emitting energy of the rare earth oxyhydrogen fluoride luminescent material with adjustable red and green color change can be adjusted in a red and green light wave band of 620-500 nm.

b. preparation of Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,20％Tb³⁺Precursor material:

b-1. Y (NO) formulated in step a at room temperature₃)₃Aqueous solution, Eu (NO)₃)₃Aqueous solution and Tb (NO)₃)₃Mixing 750 mu L, 50 mu L and 200 mu L of the aqueous solution, adding 60mL of deionized water, and uniformly stirring and mixing to obtain a rare earth ion mixed solution;

b-2, adding 150mmol of NH into the rare earth ion mixed solution prepared in the step b-1₄NO₃Stirring in water bath at 80 deg.C to make NH₄NO₃Completely dissolving to obtain a mixed solution of rare earth hydroxides, and slowly dropwise adding the alkaline regulating solution prepared in the step a into the mixed solution of rare earth hydroxides until the mixed solution of rare earth hydroxidesThe pH value is 7, then the rare earth hydroxide mixed solution is continuously stirred and reacts for 1h for hydrothermal reaction, after the hydrothermal reaction is finished, the reaction product is repeatedly washed and centrifuged for 3 times by deionized water and absolute ethyl alcohol, then the drying under normal pressure is carried out at the temperature of 60 ℃, and the rare earth layered hydroxide Y is obtained by collection₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,20％Tb³⁺As precursor material for standby;

c. preparation of Y (OH)_2.02F_0.98:5％Eu³⁺,20％Tb³⁺：

c-1, adopting fluorine-containing inorganic salt NH₄F is used as a fluorinating agent, 2mmol of NH is mixed according to a certain stoichiometric ratio at room temperature₄F and 0.2g of Y prepared in said step b₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,20％Tb³⁺The precursor materials are mixed evenly, 30mL of deionized water is added, and the mixture is stirred continuously until NH is achieved₄F is completely dissolved to obtain a reactant mixed liquid system;

c-2, slowly dripping the acidic regulating solution prepared in the step a into the reactant mixed solution system prepared in the step c-1 until the pH value of the reactant mixed solution system is 8.0, stirring at the temperature of 80 ℃, carrying out water bath fluorination reaction for 3 hours, washing with deionized water and absolute ethyl alcohol after the reaction is finished, centrifuging for 3 times respectively, and then drying at the temperature of 60 ℃ under normal pressure to obtain Y (OH)_2.02F_0.98:5％Eu³⁺,20％Tb³⁺A color-changing adjustable luminescent material.

This example uses Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,20％Tb³⁺Synthesis of Y (OH) by fluorination as precursor Material under Water bath conditions_2.02F_0.98:5％Eu³⁺,20％Tb³⁺Thereby obtaining the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green color change. In the embodiment, the anion exchange characteristic of the LRHs is utilized to fluorinate the LRHs, so that the preparation of the rare earth hydroxide fluoride is a better synthetic route. Red and green color-changing adjustable rare earth hydrogen prepared by the embodimentThe oxyfluoride luminescent material takes rare earth oxyhydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxyhydrogen fluoride, and the crystal structure of the oxyfluoride luminescent material is doped with rare earth luminescent ions Eu³⁺And Tb³⁺The light emission can be adjusted in the red and green light band of 620-500 nm. The preparation method has the advantages of simple preparation process, mild conditions, short preparation period, suitability for mass preparation, low energy consumption and environmental friendliness. The preparation method is a water bath condition, so that organic groups are not attached to the surface of the obtained material, the application range is widened, and the luminous efficiency is improved.

Example six:

in this embodiment, a red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, which has a chemical formula of Y (OH)_2.02F_0.98:5％Eu³⁺,40％Tb³⁺The crystal structure of which is doped with rare earth luminous ion Eu³⁺And Tb³⁺，Eu³⁺And Tb³⁺Partial displacement of rare earth ions by Y in a matrix³⁺Wherein 5 percent or 40 percent is the mass percentage concentration of doped ions in the composite rare earth oxyhydrogen fluoride, Eu³⁺Doping amount of (5%), Tb³⁺The doping amount of (A) is 40%. The light emitting energy of the rare earth oxyhydrogen fluoride luminescent material with adjustable red and green color change can be adjusted in a red and green light wave band of 620-500 nm.

b. preparation of Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,40％Tb³⁺Precursor material:

b-1. Y (NO) formulated in step a at room temperature₃)₃Aqueous solution, Eu (NO)₃)₃Aqueous solution and Tb (NO)₃)₃Mixing 550 mu L, 50 mu L and 400 mu L of the aqueous solution, adding 60mL of deionized water, and uniformly stirring and mixing to obtain a rare earth ion mixed solution;

b-2, adding 150mmol of NH into the rare earth ion mixed solution prepared in the step b-1₄NO₃Stirring in water bath at 80 deg.C to make NH₄NO₃Completely dissolving to obtain a rare earth hydroxide mixed solution, slowly dropwise adding the alkaline regulating solution prepared in the step a into the rare earth hydroxide mixed solution until the pH value of the rare earth hydroxide mixed solution is 7, continuously stirring and reacting the rare earth hydroxide mixed solution for 1h to perform hydrothermal reaction, repeatedly washing and centrifuging reaction products for 3 times by using deionized water and absolute ethyl alcohol after the hydrothermal reaction is finished, drying at the temperature of 60 ℃ under normal pressure, and collecting to obtain a rare earth layered hydroxide Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,40％Tb³⁺As precursor material for standby;

c. preparation of Y (OH)_2.02F_0.98:5％Eu³⁺,40％Tb³⁺：

c-1, adopting fluorine-containing inorganic salt NH₄F is used as a fluorinating agent, 2mmol of NH is mixed according to a certain stoichiometric ratio at room temperature₄F and 0.2g of Y prepared in said step b₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,40％Tb³⁺The precursor materials are mixed evenly, 30mL of deionized water is added, and the mixture is stirred continuously until NH is achieved₄F is completely dissolved to obtain a reactant mixed liquid system;

c-2, slowly dripping the acidic regulating solution prepared in the step a into the reactant mixed solution system prepared in the step c-1 until the pH value of the reactant mixed solution system is 8.0, stirring at the temperature of 80 ℃, carrying out water bath fluorination reaction for 3 hours, washing with deionized water and absolute ethyl alcohol after the reaction is finished, centrifuging for 3 times respectively, and then drying at the temperature of 60 ℃ under normal pressure to obtain Y (OH)_2.02F_0.98:5％Eu³⁺,40％Tb³⁺Color-changing adjustable luminescenceA material.

This example uses Y₂(OH)₅NO₃·1.4H₂O:5％Eu³⁺,40％Tb³⁺Synthesis of Y (OH) by fluorination as precursor Material under Water bath conditions_2.02F_0.98:5％Eu³⁺,40％Tb³⁺Thereby obtaining the rare earth oxy-hydrogen fluoride luminescent material with adjustable red and green color change. In the embodiment, the anion exchange characteristic of the LRHs is utilized to fluorinate the LRHs, so that the preparation of the rare earth hydroxide fluoride is a better synthetic route. The red-green color-changing adjustable rare earth oxy-hydrogen fluoride luminescent material prepared by the embodiment takes rare earth oxy-hydrogen fluoride as a matrix and luminescent rare earth elements as doping elements to form a composite rare earth oxy-hydrogen fluoride, and a crystal structure of the composite rare earth oxy-hydrogen fluoride is doped with rare earth luminescent ions Eu³⁺And Tb³⁺The light emission can be adjusted in the red and green light band of 620-500 nm. The preparation method has the advantages of simple preparation process, mild conditions, short preparation period, suitability for mass preparation, low energy consumption and environmental friendliness. The preparation method is a water bath condition, so that organic groups are not attached to the surface of the obtained material, the application range is widened, and the luminous efficiency is improved.

Experimental testing comparative analysis:

the rare earth oxyhydrogen fluoride luminescent materials prepared in the first embodiment to the sixth embodiment of the invention are respectively tested, the chemicals and the reagents used in the embodiments are analytically pure, and the reaction solvents used in the synthesis are deionized water.

Performing X-ray diffraction analysis on the rare earth oxyhydrogen fluoride luminescent materials prepared in the first to sixth embodiments of the invention by using a D/MAX2500 type powder X-ray diffractometer from Japan science company; FIG. 1 shows Y (OH) prepared in example one_2.02F_0.98:5％Eu³⁺,1.25％Tb³⁺And Y (OH) obtained in examples two, three, four, five and six_mF_3-m:x％Eu³⁺,y％Tb³⁺X-ray diffraction (XRD) pattern of (a). In fig. 1, the abscissa is 2 θ, the unit: degree; the ordinate is the relative intensity. Reference numerals 1 to 6 for the diffraction patterns in FIG. 1 correspond to the first to sixth embodiments, respectively. As can be seen from FIG. 1, the XRD pattern of the powder prepared by comparison with the PDF standard card was Y (OH)_2.02F_0.98Phase, and having good crystallinity, no other impurity phase was found, indicating that the synthetic method used in example one successfully produced pure phase Y (OH)_2.02F_0.98。

The surface morphology of the rare earth oxyhydrogen fluoride luminescent material sample prepared in the third embodiment is tested and observed by adopting a JSM-7500F scanning electron microscope of JEOL company. FIG. 2 shows Y (OH) prepared in EXAMPLE III of the present invention_2.02F_0.98:5％Eu³⁺,5％Tb³⁺Scanning Electron Microscope (SEM) images of (a). As can be seen from FIG. 2, Y (OH) prepared_2.02F_0.98:5％Eu³⁺,5％Tb³⁺The crystal grains have uniform rod-bundle-shaped appearance, the length of the crystal grains is 700nm-900nm, and the diameter of the crystal grains is 200nm-300 nm. For the infrared absorption spectrum test of the rare earth oxyhydrogen fluoride luminescent material prepared in the third embodiment, an Nicolet 380 type infrared spectrometer of the U.S. thermoelectric technology instrument ltd is adopted. FIG. 3 shows Y (OH) prepared in EXAMPLE III of the present invention_2.02F_0.98:5％Eu³⁺,5％Tb³⁺Fourier-infrared (FT-IR) spectra of (a). In fig. 3, the abscissa is the wavenumber, unit: cm^-1(ii) a The ordinate is the transmittance. As can be seen from FIG. 3, 3633cm^-1The vibration peak of the medium-diameter (-OH) group in the molecule is 560, 783cm^-1Is a Y-O vibration peak, indicated in Y (OH)_2.02F_0.98:5％Eu³⁺,5％Tb³⁺The structure has-OH and Y-O bonds.

The rare earth oxyhydrogen fluoride luminescent materials prepared in the first to sixth embodiments of the present invention were subjected to photoexcitation emission spectroscopy, and a QM 40 type steady/transient fluorescence spectrometer manufactured by PTI corporation in the united states was used. FIG. 4 shows Y (OH) prepared according to example one of the present invention_2.02F_0.98:5％Eu³⁺,1.25％Tb³⁺And Y (OH) obtained in examples two, three, four, five and six_mF_3-m:x％Eu³⁺,y％Tb³⁺Emission spectrum (PL) at an excitation wavelength of 380 nm; the abscissa is wavelength, unit: nm; the ordinate is the relative intensity. From FIG. 4It is known that the light emission peak at 380nm corresponds to Tb³⁺Is/are as follows⁵D₄-⁷F₆Transition, the luminous peak at 543nm corresponds to Tb³⁺Is/are as follows⁵D₄-⁷F₅Transition, the luminescence peak at 590nm corresponds to Eu³⁺Is/are as follows⁵D₀-⁷F₁Transition, the light-emitting peak at 615nm corresponds to Eu³⁺Is/are as follows⁵D₀-⁷F₂Transition, 685 and 690nm luminescence peaks corresponding to Eu³⁺Is/are as follows⁵D₀-⁷F₄Transition, with Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺Middle Tb³⁺Increased doping concentration, Eu³⁺The transition luminescence peak of Tb is gradually increased, and the luminescence peak corresponding to Tb is at Tb³⁺A maximum value is reached at a doping concentration of 5%.

Y (OH) prepared by examples one to six of the present invention_mF_3-m:x％Eu³⁺,y％Tb³⁺The obtained color coordinate graph is drawn by the rare earth oxyhydrogen fluoride luminescent material, and the graph is shown in figure 5. As can be seen from FIG. 5, Eu³⁺At a doping concentration of 5%, with Tb³ ⁺When the concentration is increased from 1.25% to 40%, the color coordinate points regularly move from the green light region to the red light region, so that the performance of adjusting red and green color change is realized.

In summary, the embodiments of the present invention prepare a series of rare earth oxyhydrogen fluoride luminescent materials with excellent luminescent properties and adjustable color change in red and green light bands, wherein the crystal of the rare earth oxyhydrogen fluoride luminescent materials is in a hexagonal phase crystal structure, belongs to a p 63/m space group, and Y in the crystal lattice is³⁺With OH^-And F^-Constituting eight or nine coordinates, a part of Y³⁺Is rare earth luminous ion Eu³⁺And Tb³⁺The lattice is substitutional. The material is characterized in that the matrix is Y (OH)_mF_3-mBy doping different proportions of rare earth luminescent ions Eu in crystal lattice³⁺，Tb³⁺The color change and adjustability of the luminescence in the wave bands of 500nm (green light) and 650nm (red light) are realized. The chemical formula is Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺(ii) a The preparation method utilizes the precursor material with the interlayer anion exchange characteristicY₂(OH)₅NO₃·nH₂O:x％Eu³⁺,

y％Tb³⁺Fluorination in a water bath at 80 ℃ to give Y (OH)_mF_3-m:x％Eu³⁺,y％Tb³⁺. The material has excellent red-green color-changing luminescent performance, can be used in the fields of LED fluorescent powder and the like, and has the advantages of simple and convenient preparation method, low energy consumption and better economic value.

The embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made according to the purpose of the invention, and any changes, modifications, substitutions, combinations or simplifications made according to the spirit and principle of the technical solution of the present invention shall be equivalent substitutions, so long as the purpose of the present invention is met, and the protection scope of the present invention shall not depart from the technical principle and inventive concept of the red-green color-changing adjustable rare earth oxyhydrogen fluoride luminescent material and the preparation method thereof.

Claims

1. a red-green discoloration adjustable rare earth oxyhydroxide luminescent material, it is characterized in that: take rare earth oxyhydroxide as host, take luminescent rare earth element as doping element, form a kind of composite rare earth oxyhydroxide, Its crystal structure is doped with rare earth luminescent ions Eu ³⁺ and Tb ³⁺ , and its luminescence can be adjusted in the red and green light band of 620-500 nm; Prepared as follows:

Using Y ₂ (OH) ₅ NO ₃ ·nH ₂ O:x%Eu ³⁺ and y%Tb ³⁺ as precursor materials, Y(OH) _m F _3-m :x was synthesized by fluorination under water bath conditions %Eu ³⁺ , y% Tb ³⁺ , so as to obtain a rare earth oxyfluoride luminescent material with adjustable red and green discoloration. In the chemical formula of the precursor material, n is the number of crystal water in the chemical formula, and n is 1.4; including the following step:

a. Prepare the solution required in the preparation process:

a-1. Dissolve Y(NO ₃ ) ₃ ·6H ₂ O in deionized water to prepare a Y(NO ₃ ) ₃ aqueous solution;

a-2. Dissolve Eu(NO ₃ ) ₃ ·6H ₂ O in deionized water to prepare an Eu(NO ₃ ) ₃ aqueous solution;

a-3. Dissolve Tb(NO ₃ ) ₃ ·6H ₂ O in deionized water to prepare an aqueous solution of Tb(NO ₃ ) ₃ ;

a-4. Add deionized water to the concentrated ammonia solution with a mass concentration of 25%, and prepare an NH ₄ OH aqueous solution with a pH value of not less than 12 as an alkaline adjusting solution;

a-5. Add deionized water to the concentrated nitric acid solution with a mass concentration of 68%, and prepare an HNO aqueous solution with a pH value not greater than ₁ , as an acid adjusting solution;

b. Preparation of Y ₂ (OH) ₅ NO ₃ ·1.4H ₂ O: x% Eu ³⁺ , y% Tb ³⁺ precursor material:

b-1. At room temperature, mix the Y(NO ₃ ) ₃ aqueous solution, Eu(NO ₃ ) ₃ aqueous solution and Tb(NO ₃ ) ₃ aqueous solution prepared in step a according to a certain stoichiometric ratio, and add the Ionized water, stir and mix evenly to obtain rare earth ion mixture;

b-2. Add a certain amount of NH ₄ NO ₃ to the rare earth ion mixture prepared in the step b-1, and stir in a water bath at a temperature not higher than 80° C. to completely dissolve the NH ₄ NO ₃ to obtain rare earth hydrogen oxide mixed solution, and then slowly dropwise add the alkaline adjusting solution prepared in step a to the rare earth hydroxide mixed solution until the pH value of the rare earth hydroxide mixed solution is between 6.5-7.5, and then the rare earth hydrogen The mixture of oxides was continuously stirred for at least 1 hour for hydrothermal reaction. After the hydrothermal reaction was over, the reaction product was repeatedly washed with deionized water and absolute ethanol, centrifuged for at least 3 times each, and then heated at a temperature not lower than 60 °C. Under normal pressure drying, the rare earth layered hydroxide Y ₂ (OH) ₅ NO ₃ ·1.4H ₂ O: x% Eu ³⁺ , y% Tb ³⁺ is collected and obtained, which is used as a precursor material for use;

c. Preparation of Y(OH) _m F _3-m : x% Eu ³⁺ , y% Tb ³⁺ :

c-1. Using fluorine-containing inorganic salt as fluorinating agent, at room temperature, according to F ^- and Y ₂ (OH) ₅ NO ₃ ·nH ₂ O: x% Eu ³⁺ , y% Tb ³ in fluorine-containing inorganic salt The amount ratio of the substance of ⁺ is the ratio of 0.98:0.5, and the fluorine-containing inorganic salt and the Y ₂ (OH) ₅ NO ₃ ·1.4H ₂ O: x% Eu ³⁺ , y% Tb prepared in the step b ³⁺ The precursor material is mixed uniformly, and deionized water is added, and under continuous stirring, the fluorine-containing inorganic salt is completely dissolved, and the reactant mixed liquid system is obtained;

c-2. Slowly add the acidic adjusting solution prepared in step a to the reactant mixed liquid system prepared in the step c-1, until the pH value of the reactant mixed liquid system is 8.0-9.0, and then Stir at a temperature not higher than 80 °C, and perform a water bath fluorination reaction for at least 3 hours. After the reaction, wash with deionized water and absolute ethanol, and centrifuge for at least 3 times each, and then carry out normal pressure at a temperature not higher than 60 °C. Dry to obtain Y(OH) _m F _3-m : x%Eu ³⁺ , y%Tb ³⁺ color-changing tunable luminescent material; 0<m≤2.02 in the general chemical formula; 0<x≤5; 1.25≤y ≤40; Doped Eu ³⁺ and Tb ³⁺ rare earth element ions partially replace Y ³⁺ in the matrix Y(OH) _m F _3-m , where x% or y% is the dopant ions in the composite rare earth hydroxide The mass percentage concentration of fluoride, x% is the doping amount of Eu ³⁺ , and y% is the doping amount of Tb ³⁺ .

2. The rare-earth oxyfluoride luminescent material with adjustable red and green discoloration according to claim 1, characterized in that: its crystal is a hexagonal phase crystal structure, which belongs to the p 63/m space group, and Y ³⁺ in the lattice and OH ^- and F ^- constitute eight or nine coordination, and a part of Y ³⁺ is replaced by the lattice of rare earth luminescent ions Eu ³⁺ and Tb ³⁺ .

3. The rare earth oxyfluoride luminescent material with adjustable red and green discoloration according to claim 1, characterized in that: when preparing the rare earth ion mixed solution in the step b-1, the mixing range of a certain stoichiometric ratio is : Eu ³⁺ , Tb ³⁺ content is added according to the x, y doping ratio in the final synthesis of Y(OH) _m F _3-m : x% Eu ³⁺ , y% Tb ³⁺ .

4. The rare earth oxyfluoride luminescent material with adjustable red and green discoloration according to claim 3, characterized in that: when preparing the rare earth ion mixed solution in the step b-1, a certain stoichiometric ratio is based on the prepared The molar ratio of Y ³⁺ , Eu ³⁺ and Tb ³⁺ in the rare earth ion mixed solution is (550～937.5):50:(12.5～400) ratio, Y( _NO3 ) ₃ aqueous solution, Eu(NO3) ₃ ) ₃ aqueous solution and Tb(NO ₃ ) ₃ aqueous solution are mixed.

5 . The rare earth oxyhydroxide luminescent material with adjustable red and green discoloration according to claim 1 , wherein: Y ₂ (OH) ₅ NO ₃ ·nH ₂ O: x% is prepared in the step b-2. 6 . When Eu ³⁺ , y% Tb ³⁺ precursor material, the amount of NH ₄ NO ₃ used is an excess ratio.

6 . The rare-earth oxyfluoride luminescent material with adjustable red-green discoloration according to any one of claims 1 to 5, characterized in that: when preparing the reactant mixed liquid system in the step c-1, the fluorine-containing The inorganic salt is any one elemental salt of NH ₄ F, NaF and KF or a mixed salt of any one.