Fluoride, and preparation method therefor and use thereof

Abstract

Provided in the present application are fluoride, and a preparation method therefor and the use thereof. The chemical formula of the fluoride is A x M 1-y F z:y N 4+, wherein A comprises at least one of alkali metals and alkaline earth metal elements, M comprises at least one of IVA-group elements and IIIA-group elements, F is a fluorine element, N comprises at least one transition element, 1≤x≤3, 0≤y≤0.2, and 4≤z≤7. The preparation method of the fluoride comprises the following steps: S10, dissolving a raw material containing an N element and a raw material containing an M element in a solution P1, and mixing same, so as to obtain a first mixed solution; S20, mixing a raw material containing an element A with a solution P2, so as to obtain a second mixed solution; and S30, mixing the first mixed solution with the second mixed solution, so as to obtain fluoride.

Description

Fluoride and its preparation method and application

[0001] This application claims priority to Chinese patent application No. 202410249425.X filed on March 5, 2024, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of fluorescent materials, and in particular to a fluoride and a preparation method and application thereof. Background Art

[0003] At present, fluoride phosphors are usually prepared by ion exchange or precipitation methods, and their particle size can only reach the micron level, and cannot reach the nanometer or submicron scale. Therefore, the application of fluoride phosphors in Mini / Micro-LED displays and other fields is limited. Technical issues

[0004] The main purpose of this application is to propose a fluoride and its preparation method and application, aiming to solve the problem of how to adjust the particle size of fluoride. Technical Solutions

[0005] To achieve the above objectives, the present application provides a fluoride, the chemical formula of which is shown in Formula I;

[0006] A x M 1-y F z:y N 4+ Formula I,

[0007] wherein A comprises at least one of an alkali metal and an alkaline earth metal element, M comprises at least one of a Group IVA and a Group IIIA element, F is a fluorine element, N comprises at least one transition element, 1≤x≤3, 0≤y≤0.2, 4≤z≤7;

[0008] The preparation method of the fluoride comprises the following steps:

[0009] S10, dissolving a raw material containing the N element and a raw material containing the M element in the solution P1 and mixing them to obtain a first mixed solution;

[0010] S20, mixing the raw material containing element A with solution P2 to obtain a second mixed solution;

[0011] S30, mixing the first mixed solution and the second mixed solution and performing post-processing to obtain a fluoride;

[0012] The solution P1 includes a good solvent, and the solution P2 includes a poor solvent and a good solvent.

[0013] In one embodiment, the particle size of the fluoride is 50 nm to 30 μm.

[0014] In one embodiment, the greater the volume percentage of the poor solvent in the solution P1 and the solution P2, the smaller the particle size of the fluoride.

[0015] In one embodiment, the poor solvent includes glacial acetic acid, and the good solvent includes hydrofluoric acid.

[0016] The present application also proposes a preparation method of the above-mentioned fluoride for adjusting the particle size of the fluoride, the preparation method comprising the following steps:

[0017] S10, dissolving a raw material containing the N element and a raw material containing the M element in the solution P1 and mixing them to obtain a first mixed solution;

[0018] S20, mixing the raw material containing element A with solution P2 to obtain a second mixed solution;

[0019] S30, mixing the first mixed solution and the second mixed solution, and performing post-processing to obtain a fluoride;

[0020] The solution P1 includes a good solvent, and the solution P2 includes a poor solvent and a good solvent.

[0021] In one embodiment, the good solvent includes at least one of hydrofluoric acid, hydrochloric acid, phosphoric acid and nitric acid;

[0022] The poor solvent includes at least one of weak acid, alcohol, ketone, ether, N,N-dimethylamide, dimethyl sulfoxide, ester, and benzene.

[0023] In one embodiment, in the solution P1 and the solution P2, the volume percentage of the poor solvent is V, and 0<V<100%.

[0024] In one embodiment, the raw material containing element A includes at least one of fluoride containing element A, nitrate containing element A, sulfate containing element A, hydrogen sulfate containing element A, carbonate containing element A, hydrogen carbonate containing element A, acetate containing element A, and acetylacetonate containing element A; and / or,

[0025] The raw material containing N element includes at least one of fluoride containing N element, nitrate containing N element, sulfate containing N element, bisulfate containing N element, carbonate containing N element, bicarbonate containing N element, acetate containing N element and acetylacetonate containing N element; and / or,

[0026] The raw material containing element M includes at least one of fluoride containing element M, nitrate containing element M, sulfate containing element M, bisulfate containing element M, carbonate containing element M, bicarbonate containing element M, acetate containing element M and acetylacetonate containing element M.

[0027] In one embodiment, the raw material containing N element and the raw material containing A element include K2MnF6, wherein A is potassium element, N is manganese element, and fluorine element is also provided; the raw material containing M element includes GeO2.

[0028] In one embodiment, in step S30, the post-processing includes washing and dispersing.

[0029] During the washing process, the third mixed liquid is washed with an acid solution and a neutral solvent respectively;

[0030] The acid solution includes at least one of hydrofluoric acid, hydrochloric acid, phosphoric acid, nitric acid, formic acid, acetic acid, propionic acid, butyric acid and glyoxylic acid;

[0031] The neutral solvent includes at least one of alcohol, ketone, benzene and dimethyl sulfoxide;

[0032] In the dispersion treatment process, an organic solvent is used to disperse the third mixed liquid after the washing treatment to obtain a fluoride dispersion liquid.

[0033] In one embodiment, the organic solvent includes at least one of acetic acid, propionic acid, butyric acid, glyoxylic acid, alcohol, ketone, benzene, and dimethyl sulfoxide.

[0034] In one embodiment, in step S30, the post-processing includes washing and drying;

[0035] During the drying process, the drying temperature is 60-80° C. and the drying time is 4-8 h.

[0036] The present application also proposes an application of the aforementioned fluoride or the fluoride prepared by the aforementioned preparation method in the field of liquid crystal backlight or LED lighting.

[0037] In one embodiment, the fluoride is prepared into a dispersion liquid and coated on a liquid crystal backlight source to form a fluorescent film.

[0038] In one embodiment, the fluoride is made into powder and added to an LED lighting source to increase the brightness of the LED light source or change the color of the LED light source. Beneficial effects

[0039] In the technical solution provided in the present application, the particle size of the fluoride can be adjusted by adjusting the ratio of the poor solvent to the good solvent in solution P1 and solution P2. The larger the proportion of the poor solvent in solution P1 and solution P2, the lower the solubility of the fluoride, the more crystal nuclei formed per unit time, and the smaller the particle size of the fluoride. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 shows the K2GeF6:Mn obtained in Example 9 of this application. 4+ Actual comparison of the dispersion under natural light and UV light;

[0042] FIG2 is an XRD pattern of Examples 1 to 4 and Comparative Example 1 in this application;

[0043] FIG3 is the excitation spectra of Examples 1 to 4 and Comparative Example 1 in this application;

[0044] FIG4 is an XRD pattern of Examples 5 to 7 in this application;

[0045] FIG5 is an XRD pattern of Example 8 in the present application;

[0046] FIG6 is a SEM image of Examples 1 to 4 and Comparative Example 1 in this application;

[0047] FIG7 is a TEM image of Example 5 in this application;

[0048] FIG8 is a SEM image of Example 6 in this application;

[0049] FIG9 is a SEM image of Example 7 in this application;

[0050] FIG10 is a SEM image of Example 8 in this application;

[0051] FIG11 is a diagram of K2GeF6:Mn in Example 9 used in this application. 4+ Actual image of the red fluorescent film made from the dispersion being irradiated under 365 nm ultraviolet light.

[0052] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. Modes for Carrying Out the Invention

[0053] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0054] It should be noted that, in the embodiments, those without specifying specific conditions, are carried out according to conventional conditions or the conditions recommended by the manufacturer. Those for reagents or instruments used that do not specify the manufacturer are conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes schemes A, B, or A and B that meet the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but must be based on the ability of those of ordinary skill in the art to achieve. When the combination of the technical solutions is mutually contradictory or cannot be achieved, it should be considered that the combination of such technical solutions does not exist and is not within the scope of protection required in this application. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of this application.

[0055] At present, fluoride phosphors are usually prepared by ion exchange or precipitation methods, and their particle size can only reach the micron level, and cannot reach the nanometer or submicron scale. Therefore, the application of fluoride phosphors in Mini / Micro-LED displays and other fields is limited.

[0056] In view of this, the present application proposes a fluoride, the chemical formula of the fluoride is shown in Formula I;

[0057] A x M 1-y F z :yN 4+ Formula I,

[0058] Wherein, A includes at least one of alkali metal and alkaline earth metal elements, M includes at least one of Group IVA and Group IIIA elements, F is fluorine, N includes at least one transition element, 1≤x≤3, 0≤y≤0.2, 4≤z≤7; the preparation method of the fluoride includes the following steps: S10, dissolving a raw material containing the N element and a raw material containing the M element in a solution P1 and mixing them to obtain a first mixed liquid; S20, mixing the raw material containing the A element with the solution P2 to obtain a second mixed liquid; S30, mixing the first mixed liquid and the second mixed liquid and then post-treating them to obtain a fluoride; wherein, the solution P1 includes a good solvent, and the solution P2 includes a poor solvent and a good solvent.

[0059] It is understood that the good solvent in the solution P1 and the solution P2 is a solvent that can dissolve the fluoride, and the poor solvent in the solution P2 is a solvent with low solubility for the fluoride. Preferably, in some embodiments of the present application, the poor solvent includes glacial acetic acid, and the good solvent includes hydrofluoric acid.

[0060] In the technical solution provided in the present application, the particle size of the fluoride can be adjusted by adjusting the ratio of the poor solvent to the good solvent in the solution P. The larger the proportion of the poor solvent in the solution P1 and the solution P2, the lower the solubility of the fluoride, the more crystal nuclei formed per unit time, and the smaller the particle size of the fluoride.

[0061] In one embodiment, the particle size of the fluoride is 50 nm to 30 μm. By preparing fluorides with different particle sizes, the fluoride can be used to prepare different fluorescent materials according to needs, thereby expanding the application range of fluoride.

[0062] In one embodiment, the greater the volume percentage of the poor solvent in solution P1 and solution P2, the smaller the particle size of the fluoride.

[0063] It should be noted that the volume of the solution P1 is νP1, the volume of the solution P2 is νP2, the volume of the poor solvent in the solution P2 is ν1, the volume of the good solvent is ν2, ν1+ν2=νP2;

[0064] The volume percentage of the poor solvent is V, which represents the ratio of the volume of the poor solvent to the sum of the volumes of the good solvent and the poor solvent in the entire system. It is numerically equal to the volume of the poor solvent divided by the sum of the volumes of solution P1 and solution P2, that is, V=ν2 / (νP1+νP2)×100%.

[0065] The present application also proposes a preparation method of the fluoride as described above, which is used to adjust the particle size of the fluoride. The preparation method comprises the following steps: S10, dissolving a raw material containing the N element and a raw material containing the M element in a solution P1 and mixing them to obtain a first mixed liquid; S20, mixing the raw material containing the A element with the solution P2 to obtain a second mixed liquid; S30, after mixing the first mixed liquid and the second mixed liquid, performing post-treatment to obtain a fluoride; wherein, the solution P1 comprises a good solvent, and the solution P2 comprises a poor solvent and a good solvent.

[0066] By dissolving the raw material containing the N element and the raw material containing the M element in solution P1 and mixing them, and mixing the raw material containing the A element with solution P2, the M element, the N element and the A element can be dispersed in the system in advance, respectively, and react quickly in step S30 to generate fluoride crystal nuclei with low solubility, thereby improving the reaction efficiency. During the mixing process in step S30, the rate of crystal nucleation is accelerated, which facilitates the control of the particle size of the fluoride.

[0067] In one embodiment, the good solvent includes at least one of hydrofluoric acid, hydrochloric acid, phosphoric acid, and nitric acid; and the poor solvent includes at least one of a weak acid, an alcohol, a ketone, an ether, N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), an ester, and benzene. This arrangement allows the poor solvent to rapidly disperse the produced fluoride in the reaction system, reducing the particle size of the resulting individual fluoride particles.

[0068] In one embodiment, the volume percentage of the poor solvent in the solution P1 and the solution P2 is V, where 0<V<100%.

[0069] With such a configuration, the particle size of the fluoride can be changed according to the volume percentage of the poor solvent. By setting the volume percentage of the poor solvent to 0-100%, the particle size of the fluoride can be adjusted within the maximum range.

[0070] In one embodiment, the raw material containing element A includes at least one of fluoride containing element A, nitrate containing element A, sulfate containing element A, bisulfate containing element A, carbonate containing element A, bicarbonate containing element A, acetate containing element A, and acetylacetonate containing element A; and / or, the raw material containing element N includes at least one of fluoride containing element N, nitrate containing element N, sulfate containing element N, bisulfate containing element N, carbonate containing element N, bicarbonate containing element N, acetate containing element N, and acetylacetonate containing element N; and / or, the raw material containing element M includes at least one of fluoride containing element M, nitrate containing element M, sulfate containing element M, bisulfate containing element M, carbonate containing element M, bicarbonate containing element M, acetate containing element M, and acetylacetonate containing element M. In some embodiments of the present application, the raw material containing the N element and the raw material containing the A element include K2MnF6, wherein A is potassium element, N is manganese element, and fluorine element is also provided; the raw material containing the M element includes GeO2.

[0071] In addition, in some embodiments of the present application, the poor solvent includes hydrofluoric acid, which can also provide fluorine element to the fluoride, thereby providing sufficient raw materials for preparing the fluoride.

[0072] In one embodiment, in step S30, the post-treatment includes washing and dispersing. During the washing process, an acid solution and a neutral solvent are used to wash the third mixed liquid respectively. The acid solution includes at least one of hydrofluoric acid, hydrochloric acid, phosphoric acid, nitric acid, formic acid, acetic acid, propionic acid, butyric acid and glyoxylic acid. The neutral solvent includes at least one of alcohol, ketone, benzene and dimethyl sulfoxide. During the dispersing process, an organic solvent is used to disperse the third mixed liquid after washing to obtain a fluoride dispersion.

[0073] It should be noted that the organic solvent includes at least one of acetic acid, propionic acid, butyric acid, glyoxylic acid, alcohol, ketone, benzene and dimethyl sulfoxide.

[0074] By adopting washing treatment, the unreacted raw materials in the system can be washed away, thereby improving the purity of the fluoride in the product; by adopting dispersion treatment, the fluoride can be stored in the form of a dispersion liquid, so that it can be used to prepare light-emitting backplanes and light-emitting elements.

[0075] In one embodiment, in step S30, the post-treatment includes washing and drying. During the drying process, the drying temperature is 60-80°C and the drying time is 4-8 hours. By using the drying process, the fluoride can be stored in the form of a dry powder, thereby extending the storage time of the fluoride and reducing storage and maintenance costs. Furthermore, the fluoride can be used in the preparation of a light-emitting backplane in the form of nanocrystals or nanosheets.

[0076] By setting the drying temperature and time, the fluoride powder can be obtained by rapid drying, while the phenomenon of decomposition and deterioration of the fluoride caused by long-term high-temperature drying can be avoided.

[0077] The present application also proposes a fluoride prepared by the aforementioned preparation method.

[0078] The present application also proposes an application of the aforementioned fluoride or the fluoride prepared by the aforementioned preparation method in the field of liquid crystal backlight or LED lighting.

[0079] It should be noted that the application can be to prepare a gel-like fluorescent material and then apply it to liquid crystal backlights or LED lighting. By using a gel-like fluorescent material, it is easier to coat the fluorescent material on the light source panel, improve the dispersion of the fluoride in the fluorescent material, and enhance the uniformity of the fluorescence excited by the light source.

[0080] In some embodiments of the present application, the fluoride is made into a dispersion liquid, which can be coated on a liquid crystal backlight source to form a fluorescent film; in another embodiment of the present application, the fluoride is made into a powder, which can be added to an LED lighting source to increase the brightness of the LED light source or change the color of the LED light source.

[0081] The technical solution of the present application is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present application and are not used to limit the present application.

[0082] Example 1

[0083] This embodiment provides K2GeF6:Mn 4+ The preparation method of KGFM comprises the following steps:

[0084] 1) Weigh 0.1 g of K2MnF6 and 1.0 g of GeO2 in 22 mL of HF to obtain the first mixed solution;

[0085] 2) Weigh 1.8 g of KHF2 into 200 mL of glacial acetic acid solution to obtain a second mixed solution, in which the volume percentage of glacial acetic acid in the glacial acetic acid solution is 90%;

[0086] 3) Pour the first mixed solution into the second mixed solution. After the reaction is complete, wash with glacial acetic acid and ethanol three times in sequence, and then dry in a drying oven at 70°C for 6 h to obtain K2GeF6:Mn 4+ powder.

[0087] Example 2

[0088] This embodiment provides K2GeF6:Mn 4+ The preparation method is similar to that of Example 1, except that in step 2) of this embodiment, the volume percentage of glacial acetic acid is 80%.

[0089] Example 3

[0090] This embodiment provides K2GeF6:Mn 4+ The preparation method is similar to that of Example 1, except that in step 2) of this embodiment, the volume percentage of glacial acetic acid is 60%.

[0091] Example 4

[0092] This embodiment provides K2GeF6:Mn 4+ The preparation method is similar to that of Example 1, except that in step 2) of this embodiment, the volume percentage of glacial acetic acid is 40%.

[0093] Example 5

[0094] This embodiment provides K2SiF6:Mn 4+ The preparation method of KSFM comprises the following steps:

[0095] 1) Weigh 0.1 g of K2MnF6 and 0.46 g of SiO2 in 22 mL of HF to obtain the first mixed solution;

[0096] 2) Weigh 1.8 g of KHF2 into 200 mL of glacial acetic acid solution to obtain a second mixed solution, in which the volume percentage of glacial acetic acid in the glacial acetic acid solution is 90%;

[0097] 3) Pour the first mixed solution into the second mixed solution. After the reaction is completed, wash it with glacial acetic acid and ethanol several times in sequence, and then dry it in a drying oven at 70°C for 6 h to obtain K2SiF6:Mn 4+ powder.

[0098] Example 6

[0099] This embodiment provides K2SiF6:Mn 4+ The preparation method comprises the following steps:

[0100] 1) Weigh 0.1 g of K2MnF6 and 0.46 g of SiO2 in 22 mL of HF to obtain the first mixed solution;

[0101] 2) Weigh 1.8 g of KHF2 into 125 mL of glacial acetic acid solution to obtain a second mixed solution, in which the volume percentage of glacial acetic acid in the glacial acetic acid solution is 85%;

[0102] 3) Pour the first mixed solution into the second mixed solution. After the reaction is completed, wash it with glacial acetic acid and ethanol several times in sequence, and then dry it in a drying oven at 70°C for 6 h to obtain K2SiF6:Mn 4+ powder.

[0103] Example 7

[0104] This embodiment provides K2SiF6:Mn 4+ The preparation method comprises the following steps:

[0105] 1) Weigh 0.1 g of K2MnF6 and 0.46 g of SiO2 in 22 mL of HF to obtain the first mixed solution;

[0106] 2) Weigh 1.8 g of KHF2 into 52 mL of glacial acetic acid solution to obtain a second mixed solution, in which the volume percentage of glacial acetic acid in the glacial acetic acid solution is 70%;

[0107] 3) Pour the first mixed solution into the second mixed solution. After the reaction is completed, wash it with glacial acetic acid and ethanol several times in sequence, and then dry it in a drying oven at 70°C for 6 h to obtain K2SiF6:Mn 4+ powder.

[0108] Example 8

[0109] This embodiment provides K2TiF6:Mn 4+ The preparation method of KTFM comprises the following steps:

[0110] 1) Weigh 0.1 g of K2MnF6 and 0.613 g of TiO2 in 22 mL of HF to obtain the first mixed solution;

[0111] 2) Weigh 1.8 g of KHF2 into 200 mL of glacial acetic acid solution to obtain a second mixed solution, in which the volume percentage of glacial acetic acid in the glacial acetic acid solution is 90%;

[0112] 3) Pour the first mixed solution into the second mixed solution. After the reaction is completed, wash it with glacial acetic acid and ethanol several times in sequence, and then dry it in a drying oven at 70°C for 6 h to obtain K2TiF6:Mn 4+ powder.

[0113] Example 9

[0114] This embodiment provides K2GeF6:Mn 4+ The preparation method comprises the following steps:

[0115] 1) Weigh 0.1 g of K2MnF6 and 1.0 g of GeO2 in 22 mL of HF to obtain the first mixed solution;

[0116] 2) Weigh 1.8 g of KHF2 into 200 mL of glacial acetic acid solution to obtain a second mixed solution, in which the volume percentage of glacial acetic acid in the glacial acetic acid solution is 90%;

[0117] 3) Pour the first mixed solution into the second mixed solution. After the reaction is completed, wash it with glacial acetic acid and ethanol several times in sequence, disperse it in acetic acid and store it to obtain K2GeF6:Mn 4+ dispersion.

[0118] K2GeF6:Mn obtained in Example 9 4+ The actual comparison of the dispersion under natural light and ultraviolet light is shown in Figure 1.

[0119] Comparative Example 1

[0120] This comparative example provides K2GeF6:Mn 4+ The preparation method is similar to that of Example 1, except that in step 2) of this embodiment, the glacial acetic acid solution is replaced by 100% hydrofluoric acid.

[0121] X-ray diffraction detection was performed on Examples 1 to 8 and Comparative Example 1, respectively, to obtain XRD patterns of Examples 1 to 7 and Comparative Example 1, and excitation spectra of Examples 1 to 4, wherein the XRD patterns of Examples 1 to 4 and Comparative Example 1 are shown in FIG2 , the excitation spectra of Examples 1 to 4 and Comparative Example 1 are shown in FIG3 , the XRD patterns of Examples 5 to 7 are shown in FIG4 , and the XRD pattern of Example 8 is shown in FIG5 .

[0122] As shown in Figure 3, the emission spectra of Examples 1-4 and Comparative Example 1 were obtained using blue light excitation at a wavelength of 456 nm. The fluorescence emission intensity at a wavelength of 631 nm decreased with increasing volume percentage of HAc, with the fluorescence intensity being weakest at 90% and strongest at 0%.

[0123] As can be seen from FIG4 , the XRD patterns of Examples 5 to 7 match the standard card of K 2 SiF 6 (PDF 85-1382), and no obvious impurity peaks appear, indicating that the synthesized products are pure KSFM phases.

[0124] As can be seen from FIG5 , the XRD pattern of Example 8 matches the standard card of K 2 TiF 6 (PDF 08-0488) and has no impurity peaks, indicating that the prepared sample is a pure phase.

[0125] The raw materials and their amounts used in Examples 1 to 4 and Comparative Example 1 are shown in Table 1.

[0126] Table 1 Raw materials and their addition amounts used in Examples 1 to 4 and Comparative Example 1

[0127] Item Example 1 Example 2 Example 3 Example 4 Comparative Example 1 HF-1 (mL) 2228202028K2MnF6 (g) 0.10.10.10.10.1GeO2 (g) 1.01.01.01.01.0CH3COOH (mL) 20011242180HF-2 (mL) 008813KHF2 (g) 1.81.81.81.81.8V90%80%60%40%0%

[0128] In Table 1, HF-1 represents the amount of hydrofluoric acid added in step 1), HF-2 represents the amount of hydrofluoric acid added in step 2), and V represents the volume percentage of the poor solvent in the system. In Examples 1 to 4 and Comparative Example 1, V = νHAc / (νHAc + νHF-1 + νHF-2), where νHAc represents the volume of CH3COOH, νHF-1 represents the volume of HF-1, and νHF-2 represents the volume of HF-2.

[0129] Electron microscopy was performed on Examples 1 to 7 and Comparative Example 1, respectively, to obtain SEM images (scanning electron microscope images) of Examples 1 to 4, Examples 6 to 7 and Comparative Example 1, and a TEM image (transmission electron microscope image) of Example 5, wherein the SEM images of Examples 1 to 4 and Comparative Example 1 are shown in Figure 6, the TEM image of Example 5 is shown in Figure 7, the SEM image of Example 6 is shown in Figure 8, the SEM image of Example 7 is shown in Figure 9, and the SEM image of Example 8 is shown in Figure 10.

[0130] As can be seen from Figure 6, the average particle sizes of the fluorides prepared in Examples 1 to 4 and Comparative Example 1 are 90 nm, 200 nm, 500 nm, 7 μm, and 30 μm, respectively;

[0131] As can be seen from Figure 7, the average particle size of the fluoride prepared in Example 5 is 50 nm;

[0132] As can be seen from Figure 8, the average particle size of the fluoride prepared in Example 6 is 87 nm;

[0133] As can be seen from Figure 9, the average particle size of the fluoride prepared in Example 7 is 700 nm;

[0134] As can be seen from FIG10 , the average particle size of the fluoride prepared in Example 8 is 3 μm.

[0135] Take K2GeF6:Mn prepared in Example 9 4+ 8 mL of the dispersion was mixed with 8 mL of silica gel to produce a stable KGFM / silicone ink. The KGFM / silicone ink was then doctored to produce a red fluorescent film. When exposed to 365 nm UV light, the film emitted a dazzling red glow, as shown in Figure 11. This makes it suitable for use as a phosphor film in Mini-LED backlights.

[0136] After testing and analysis, the following conclusions were drawn:

[0137] (1) The grain size of the phosphor can be controlled by the volume percentage of the poor solvent (such as glacial acetic acid). The larger the volume percentage of the poor solvent, the smaller the grain size of the product. When the volume percentage of glacial acetic acid is 90%, K2GeF6:Mn 4+ The average particle size is 90 nm.

[0138] (2) The poor solvent co-precipitation method is universal and can be used to prepare fluorides of different particle sizes, including KGFM nanoparticles, KSFM nanocrystals or colloids, and KTFM nanosheets.

[0139] The above description is only a preferred embodiment of the present application and does not limit the patent scope of the present application. All equivalent structural transformations made using the contents of the present application specification under the application concept of the present application, or direct / indirect application in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A fluoride, wherein The chemical formula of the fluoride is shown in Formula I; A x M 1-y F z:y N 4+ Formula I wherein A comprises at least one of an alkali metal and an alkaline earth metal element, M comprises at least one of a Group IVA and a Group IIIA element, F is a fluorine element, N comprises at least one transition element, 1≤x≤3, 0≤y≤0.2, 4≤z≤7; The preparation method of the fluoride comprises the following steps: S10, dissolving a raw material containing the N element and a raw material containing the M element in the solution P1 and mixing them to obtain a first mixed solution; S20, mixing the raw material containing element A with solution P2 to obtain a second mixed solution; S30, mixing the first mixed solution and the second mixed solution, and performing post-processing to obtain a fluoride; The solution P1 includes a good solvent, and the solution P2 includes a poor solvent and a good solvent.

2. The fluoride according to claim 1, wherein The particle size of the fluoride is 50 nm to 30 μm.

3. The fluoride according to claim 1, wherein The greater the volume percentage of the poor solvent in the solution P1 and the solution P2, the smaller the particle size of the fluoride.

4. The fluoride according to claim 1, wherein The poor solvent includes glacial acetic acid, and the good solvent includes hydrofluoric acid.

5. A method for preparing a fluoride according to any one of claims 1 to 4, for adjusting the particle size of the fluoride, wherein: The preparation method comprises the following steps: S10, dissolving a raw material containing the N element and a raw material containing the M element in the solution P1 and mixing them to obtain a first mixed solution; S20, mixing the raw material containing element A with solution P2 to obtain a second mixed solution; S30, mixing the first mixed solution and the second mixed solution, and performing post-processing to obtain a fluoride; The solution P1 includes a good solvent, and the solution P2 includes a poor solvent and a good solvent.

6. The preparation method according to claim 5, wherein The good solvent includes at least one of hydrofluoric acid, hydrochloric acid, phosphoric acid and nitric acid; The poor solvent includes at least one of weak acid, alcohol, ketone, ether, N,N-dimethylamide, dimethyl sulfoxide, ester, and benzene.

7. The preparation method according to claim 5, wherein In the solution P1 and the solution P2, the volume percentage of the poor solvent is V, and 0<V<100%.

8. The preparation method according to claim 5, wherein The raw material containing element A includes at least one of fluoride containing element A, nitrate containing element A, sulfate containing element A, hydrogen sulfate containing element A, carbonate containing element A, hydrogen carbonate containing element A, acetate containing element A and acetylacetonate containing element A; and / or, The raw material containing N element includes at least one of fluoride containing N element, nitrate containing N element, sulfate containing N element, bisulfate containing N element, carbonate containing N element, bicarbonate containing N element, acetate containing N element and acetylacetonate containing N element; and / or, The raw material containing element M includes at least one of fluoride containing element M, nitrate containing element M, sulfate containing element M, bisulfate containing element M, carbonate containing element M, bicarbonate containing element M, acetate containing element M and acetylacetonate containing element M.

9. The preparation method according to claim 8, wherein The raw material containing N element and the raw material containing A element include K2MnF6, wherein A is potassium element, N is manganese element, and fluorine element is also provided; the raw material containing M element includes GeO2.

10. The preparation method according to claim 5, wherein In the step S30, the post-processing includes washing and dispersing; During the washing process, the third mixed liquid is washed with an acid solution and a neutral solvent respectively; The acid solution includes at least one of hydrofluoric acid, hydrochloric acid, phosphoric acid, nitric acid, formic acid, acetic acid, propionic acid, butyric acid and glyoxylic acid; The neutral solvent includes at least one of alcohol, ketone, benzene and dimethyl sulfoxide; In the dispersion treatment process, an organic solvent is used to disperse the third mixed liquid after the washing treatment to obtain a fluoride dispersion liquid.

11. The preparation method according to claim 10, wherein The organic solvent includes at least one of acetic acid, propionic acid, butyric acid, glyoxylic acid, alcohol, ketone, benzene and dimethyl sulfoxide.

12. The preparation method according to claim 5, wherein In step S30, the post-processing includes washing and drying; During the drying process, the drying temperature is 60-80° C. and the drying time is 4-8 h.

13. Use of the fluoride according to any one of claims 1 to 4 or the fluoride prepared by the preparation method according to any one of claims 5 to 12 in the field of liquid crystal backlight or LED lighting.

14. The use according to claim 13, wherein: The fluoride is made into a dispersion liquid, which is then coated on a liquid crystal backlight source to form a fluorescent film.

15. The use according to claim 13, wherein: The fluoride is made into powder and added into an LED lighting source to improve the brightness of the LED light source or change the color of the LED light source.

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