Preparation method of electrolyte adjuvant enhanced rare earth upconversion luminescent material

Abstract

The application provides application of metal sulfate in preparation of rare earth up-conversion luminescent material; the metal includes alkali metal and / or alkaline earth metal. The application particularly applies alkali metal sulfate and / or alkaline earth metal sulfate in preparation of rare earth up-conversion luminescent material, which enhances the luminescent performance without obviously affecting the crystal phase and composition of the crystal. The application also provides a preparation method of the corresponding electrolyte adjuvant-enhanced rare earth up-conversion luminescent material, which uses alkali metal or alkaline earth metal sulfate as electrolyte adjuvant, hardly needs any post-treatment process, does not affect the original structure and proportion of the crystal, has good repeatability, involves only water as a green solvent in the whole process, has low cost, is easy to mass-produce, has good application prospect and potential economic benefits.

Description

Technical Field

[0001] This invention relates to the field of rare earth upconversion luminescent materials technology, to the application of metal sulfates in the preparation of rare earth upconversion luminescent materials, and to a method for preparing an electrolyte adjuvant-enhanced rare earth upconversion luminescent material, particularly to a method for preparing an electrolyte adjuvant-enhanced rare earth upconversion luminescent material. Background Technology

[0002] Rare-earth upconversion luminescent materials possess excellent optical properties. Compared to other luminescent materials, they exhibit advantages such as large anti-Stokes shift, long fluorescence lifetime, tunable emission color, narrow emission bandgap, good photostability, low toxicity, deep tissue penetration, and low autofluorescence interference. Therefore, they have broad application prospects in fields such as displays, biomedicine, optical sensing, anti-counterfeiting, remote photoactivation, temperature sensors, solid-state lasers, photovoltaic devices, and photocatalysis. Upconversion luminescence is an anti-Stokes process, converting low-energy light into high-energy light; specifically, it involves absorbing two or more low-energy photons and converting them into one high-energy photon. Limited by the luminescence mechanism, its theoretical efficiency limit is less than 50%. Furthermore, the relatively narrow absorption cross-section, concentration quenching, cross-relaxation, and surface quenching further restrict the relatively weak luminescence intensity and low luminescence efficiency of rare-earth upconversion luminescent materials, severely limiting their practical applications. Therefore, enhancing luminescence intensity and improving luminescence efficiency remain ongoing research goals of great significance.

[0003] Over the past few decades, researchers have developed various strategies to optimize the optical properties of rare-earth upconversion luminescence materials in order to improve the intensity and efficiency of upconversion luminescence. These strategies mainly include ion doping, sensitizer sensitization, surface plasmon resonance, and core-shell structures. For example, ion doping involves introducing luminescent inert ions in a certain proportion during the synthesis of upconversion luminescence materials, causing lattice distortion. Based on relaxed selection rules, the upconversion luminescence of rare-earth ions can be enhanced. Sensitizer sensitization involves combining sensitizers (such as organic dyes, quantum dots, etc.) on the surface of the upconversion material through chemical bonding or physical adsorption, increasing the absorption cross-section for excitation light and thus enhancing luminescence. Surface plasmon resonance enhancement utilizes the surface plasmon field to enhance excitation light absorption and amplify emitted light. This is specifically achieved by growing a metal with plasmon effects on the surface of the rare-earth upconversion luminescence material, with specific requirements on the size and morphology of the metal. Core-shell structure design helps reduce surface quenching, i.e., coating the surface of the upconversion luminescence material with a homogeneous or heterogeneous inert shell.

[0004] However, while the strategies mentioned above can significantly optimize the optical properties of rare-earth upconversion luminescent materials, they all have certain drawbacks. They either introduce foreign components that affect the original properties of the material or require complex experimental procedures. For example, the introduction of a large number of other ions may cause significant lattice distortion or even change the crystal phase; the composite of sensitizers or metals with plasmon effects with rare-earth upconversion luminescent materials is usually challenging and often affects the surface properties of the material; obtaining multilayer core-shell structures usually requires a fairly complex synthesis process, which undoubtedly places high demands on experimental operations.

[0005] Therefore, developing a new and simple strategy to enhance the luminescence performance of rare-earth upconversion luminescent materials without significantly affecting the material's composition is of great research significance and is one of the focal points of attention for many researchers in the industry. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide the application of metal sulfates in the preparation of rare earth upconversion luminescent materials, especially a method for preparing rare earth upconversion luminescent materials enhanced by electrolyte adjuvants. The present invention specifically uses alkali / alkaline earth metal sulfates as electrolyte adjuvants in the preparation of rare earth upconversion luminescent materials. This method requires almost no post-processing and does not affect the original crystal structure and ratio. The entire process involves only water as a green solvent, which is low in cost and easy to mass-produce.

[0007] This invention provides the application of metal sulfates in the preparation of rare-earth upconversion luminescent materials;

[0008] The metals include alkali metals and / or alkaline earth metals.

[0009] Preferably, the alkali metal element is selected from one or more of Li, Na, K, Rb and Cs.

[0010] Preferably, the alkaline earth metal element is selected from one or more of Be, Mg, Ca, Sr and Ba;

[0011] The specific application is to enhance luminescence performance.

[0012] Preferably, the metal sulfate is used as an electrolyte adjuvant;

[0013] During the application process, the addition of metal sulfates does not affect the original crystal structure and / or proportions of the rare earth upconversion luminescent material.

[0014] Preferably, the general formula of the rare-earth upconversion luminescent material is RE. 2-x-y Yb x Ln yO3; where 0≤x≤2, 0≤y≤2, and 2-xy≥0;

[0015] The RE is selected from one or more of Sc, Y, La, Gd, and Lu;

[0016] The Ln is selected from one or more of Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, and Tm.

[0017] Preferably, the amount of metal sulfate used in the preparation process is such that the molar ratio of metal sulfate to rare earth elements in the rare earth upconversion luminescent material is (0.01~100):1;

[0018] The rare-earth upconversion luminescent material may contain no metal elements or contain metal elements.

[0019] This invention provides a method for preparing an electrolyte adjuvant-enhanced rare-earth upconversion luminescent material, comprising the following steps:

[0020] 1) After reacting rare earth salts and electrolyte adjuvant metal sulfates in water, and then calcining them at high temperature, rare earth upconversion luminescent materials are obtained.

[0021] The rare earth elements in the rare earth salt include one or more of RE, Ln and Yb;

[0022] The RE is selected from one or more of Sc, Y, La, Gd, and Lu;

[0023] The Ln is selected from one or more of Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, and Tm;

[0024] The metal element in the metal sulfate is selected from alkali metals and / or alkaline earth metals.

[0025] Preferably, the rare earth salt includes one or more of rare earth halides, rare earth nitrates, rare earth acetates, rare earth carbonates, and rare earth sulfates.

[0026] The molar ratio of RE, Yb, Ln and the metal element is (0~1):(0~1):(0~0.1)(0.01~100).

[0027] Preferably, the reaction temperature is 30–180°C;

[0028] The reaction time is 1 to 240 hours.

[0029] Preferably, the high-temperature calcination temperature is 800–2000°C;

[0030] The high-temperature calcination time is 0.5 to 120 hours;

[0031] The atmosphere for the high-temperature calcination includes one or more of nitrogen, inert gases, and air.

[0032] This invention provides the application of metal sulfates in the preparation of rare-earth upconversion luminescent materials; the metals include alkali metals and / or alkaline earth metals. Compared with the prior art, this invention specifically applies alkali metal sulfates and / or alkaline earth metal sulfates in the preparation of rare-earth upconversion luminescent materials, enhancing luminescent performance without significantly affecting the crystal phase and composition. This invention also provides a corresponding method for preparing rare-earth upconversion luminescent materials enhanced by electrolyte adjuvants. This method uses alkali metal or alkaline earth metal sulfates as electrolyte adjuvants, requires almost no post-processing, and does not affect the original crystal structure and proportions. The entire process involves only water, a green solvent, resulting in low cost and ease of mass production.

[0033] The method for preparing rare-earth upconversion luminescent materials enhanced by electrolyte adjuvants provided by this invention is a novel strategy for enhancing rare-earth upconversion luminescence. It can significantly improve upconversion luminescence with remarkable enhancement effect. Moreover, the enhanced luminescence does not significantly affect the crystal phase and composition, and has good repeatability. At the same time, the method is simple and only uses water as a green solvent, which is conducive to industrial mass production and has good application prospects and potential economic benefits.

[0034] Experimental results show that, with Y 1.6 Yb 0.3 Er 0.1 Taking O3 crystals as an example, electrolyte adjuvants can enhance upconversion luminescence by 10.7 times. Attached Figure Description

[0035] Figure 1 To determine whether or not the electrolyte adjuvant Na2SO4 was introduced in Example 1, the resulting Y... 1.6 Yb 0.3 Er 0.1 X-ray powder diffraction pattern of O3 crystal;

[0036] Figure 2 Example 1: Ya before and after upconversion luminescence enhancement under 980nm near-infrared light excitation 1.6 Yb 0.3 Er 0.1 Upconversion fluorescence spectrum of O3 crystal;

[0037] Figure 3 Example 2: Lu before and after upconversion luminescence enhancement under 980nm near-infrared light excitation 1.78 Yb 0.2 Tm 0.02 Upconversion fluorescence spectrum of O3 crystal;

[0038] Figure 4 Example 3: Sc before and after upconversion luminescence enhancement under 980nm near-infrared light excitation 1.56 Yb 0.4 Ho 0.04 Upconversion fluorescence spectrum of O3 crystals. Detailed Implementation

[0039] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention and not for limiting the claims of the present invention.

[0040] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0041] There are no particular restrictions on the purity of any raw materials used in this invention. It is preferable to use analytical grade or the purity commonly used in the preparation of rare earth upconversion luminescent materials.

[0042] This invention provides the application of metal sulfates in the preparation of rare-earth upconversion luminescent materials;

[0043] The metals include alkali metals and / or alkaline earth metals.

[0044] In this invention, the metal includes alkali metals and / or alkaline earth metals, and can be alkali metals or alkaline earth metals.

[0045] In this invention, the alkali metal element is preferably selected from one or more of Li, Na, K, Rb and Cs, and more preferably Li, Na, K, Rb or Cs.

[0046] In this invention, the alkaline earth metal element is preferably selected from one or more of Be, Mg, Ca, Sr and Ba, and more preferably Be, Mg, Ca, Sr or Ba.

[0047] In this invention, the application is preferably an application that increases luminescence performance.

[0048] In this invention, the metal sulfate is preferably used as an electrolyte adjuvant.

[0049] In this invention, during the application process, the addition of metal sulfate preferably does not affect the original crystal structure and / or ratio of the rare earth upconversion luminescent material, and more preferably does not affect the original crystal structure or ratio of the rare earth upconversion luminescent material.

[0050] In this invention, the general formula of the rare-earth upconversion luminescent material is preferably RE. 2-x-y Yb x Ln yO3; wherein, preferably 0≤x≤2, 0≤y≤2, and 2-xy≥0. More preferably, 0.2≤x≤1.8, 0.2≤y≤1.8, even more preferably 0.5≤x≤1.5, 0.5≤y≤1.5, even more preferably 0.7≤x≤1.3, 0.7≤y≤1.2. 2-xy can be greater than or equal to 0.1, or greater than or equal to 0.3, or greater than or equal to 0.5, or greater than or equal to 0.8.

[0051] In this invention, the RE is preferably selected from one or more of Sc, Y, La, Gd and Lu, and more preferably from Sc, Y, La, Gd or Lu.

[0052] In this invention, Ln is selected from one or more of Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er and Tm, more preferably Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er or Tm.

[0053] In this invention, the amount of metal sulfate used in the preparation process is such that the molar ratio of metal sulfate to rare earth elements in rare earth upconversion luminescent material is preferably (0.01-100):1, more preferably (0.1-60):1, more preferably (1-20):1, and even more preferably (5-10):1.

[0054] In this invention, the rare-earth upconversion luminescent material preferably contains no metal elements or contains metal elements, more preferably no metal elements. Specifically, whether or not it contains metal elements depends on the calcination temperature and time; increasing the calcination temperature or time will eliminate the metal elements from the rare-earth upconversion luminescent material. The metal elements may exist in the rare-earth upconversion luminescent material in the form of sulfates or oxides.

[0055] This invention provides a method for preparing an electrolyte adjuvant-enhanced rare-earth upconversion luminescent material, comprising the following steps:

[0056] 1) After reacting rare earth salts and electrolyte adjuvant metal sulfates in water, and then calcining them at high temperature, rare earth upconversion luminescent materials are obtained.

[0057] In this invention, the rare earth elements in the rare earth salt include one or more of RE, Ln, and Yb, more preferably two or three of RE, Ln, and Yb. For example, Ln and one or more of the other two, or Yb and one or more of the other two.

[0058] In this invention, the RE is preferably selected from one or more of Sc, Y, La, Gd and Lu, and more preferably Sc, Y, La, Gd or Lu.

[0059] In this invention, Ln is selected from one or more of Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er and Tm, more preferably Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er or Tm.

[0060] In this invention, the rare earth salt preferably includes soluble rare earth salts and / or insoluble rare earth salts, more preferably soluble rare earth salts. Specifically, the rare earth salt preferably includes one or more of rare earth halides, rare earth nitrates, rare earth acetates, rare earth carbonates, and rare earth sulfates, more preferably rare earth halides, rare earth nitrates, rare earth acetates, rare earth carbonates, or rare earth sulfates. The halogen in the halide is preferably selected from one or more of F, Cl, Br, and I.

[0061] In this invention, the RE is preferably selected from one or more of Sc, Y, La, Gd and Lu, and more preferably Sc, Y, La, Gd or Lu.

[0062] In this invention, Ln is selected from one or more of Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er and Tm, more preferably Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er or Tm.

[0063] In this invention, the rare earth salts can be represented by symbols such as REL, YbL, and LnL. Wherein, L represents an anion, which can represent a halide anion, or an nitrate, acetate, carbonate, or sulfate anion.

[0064] In this invention, the metal element in the metal sulfate is selected from alkali metal elements and / or alkaline earth metal elements, more preferably alkali metal elements or alkaline earth metal elements.

[0065] In this invention, the preferred molar ratio of RE, Yb, Ln, and the metal elements in the metal sulfate is (0-1):(0-1):(0-0.1):(0.01-100). Wherein, 0-1 is preferably 0.2-0.8 or 0.4-0.6; 0-0.1 is preferably 0.01-0.08 or 0.04-0.06; and 0.01-100 is preferably 0.1-80, or 0.5-50, or 0.8-30, or 1-10, or 1.5-8, or 2-5.

[0066] In this invention, the reaction temperature is preferably 30–180°C, more preferably 50–160°C, even more preferably 70–140°C, and even more preferably 90–120°C.

[0067] In this invention, the reaction time is preferably 1 to 240 hours, more preferably 10 to 140 hours, and even more preferably 20 to 40 hours.

[0068] In this invention, the high-temperature calcination temperature is preferably 800-2000℃, more preferably 1000℃-2000℃, more preferably 1200℃-1900℃, and even more preferably 1300℃-1800℃.

[0069] In this invention, the high-temperature calcination time is preferably 0.5 to 120 hours, more preferably 5 to 70 hours, and even more preferably 10 to 20 hours.

[0070] In this invention, the atmosphere for high-temperature calcination preferably includes one or more of nitrogen, inert gas and air, and more preferably nitrogen, inert gas or air.

[0071] To complete and refine the overall technical solution and better improve the luminescence performance of rare earth upconversion luminescent materials, the preparation method of the above-mentioned electrolyte adjuvant-enhanced rare earth upconversion luminescent materials may specifically include the following:

[0072] This invention provides a method for preparing an electrolyte adjuvant-enhanced rare earth upconversion luminescent material, comprising the following steps: heating a rare earth salt compound (REL / YbL / LnL) and an adjuvant in an aqueous solution for several hours, followed by high-temperature calcination in a tube furnace for several hours to obtain a luminescent rare earth upconversion luminescent material.

[0073] Specifically, the heating temperature of the aqueous solution is 30℃~180℃;

[0074] Heating time is 1 hour to 240 hours.

[0075] Specifically, the heating temperature of the aqueous solution is 30℃~180℃; the heating time is 1h~240h.

[0076] Specifically, the aqueous solution is heated at a temperature of 60℃ to 120℃, and the heating time is 2h to 60h.

[0077] Specifically, the calcination temperature in the tubular furnace is 500℃~1800℃; the calcination time is 0.5h~120h.

[0078] Specifically, the calcination temperature in the tubular furnace is 600℃~1500℃; the calcination time is 1h~30h.

[0079] Specifically, the reactants in this invention are rare earth salt compounds (REL / YbL / LnL), and the electrolyte adjuvant is alkali metal sulfate MSO4.

[0080] Specifically, RE is selected from one of Sc, Y, La, Gd, or Lu.

[0081] Specifically, Ln is selected from one of Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, and Tm, and more preferably from one of Er, Ho, and Tm.

[0082] Specifically, M is selected from one of Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba, and more preferably from one of Li, Na, K, Rb and Cs.

[0083] Specifically, the molar ratio of the reactants REL, YbL, LnL and electrolyte adjuvant MSO4 is (0-1):(0-1):(0-0.1)(0.01-100).

[0084] Specifically, in the tubular furnace calcination reaction, the furnace atmosphere is selected from nitrogen, argon, or air.

[0085] Specifically, rare earth salt compounds include soluble rare earth salts and insoluble rare earth salts.

[0086] The first step of this invention uses water as the sole solvent to form a clear and transparent solution of soluble rare earth salts and electrolyte adjuvants within a saturation range. The purpose of preparing the solution is to better achieve dispersion and mixing between the electrolyte adjuvant and the rare earth salts. Soluble rare earth salts are better able to achieve this objective, while the formation of a dispersion using insoluble rare earth salts also achieves the technical solution described in this invention.

[0087] Specifically, the amount of the solvent water used is ≥0.5mL.

[0088] Further:

[0089] The method for preparing electrolyte adjuvant-enhanced rare-earth upconversion luminescent materials provided by the present invention includes the following steps:

[0090] Rare earth salt compounds, such as halides (referring to halide salts of rare earth elements, specifically Yb, which is an important rare earth element and acts as a sensitizer; secondly, the rare earth element of the matrix material RE is selected from Y, Sc, La, Gd, and Lu; finally, the activator ion Ln for upconversion luminescence is selected from Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, and Tm, which are basically essential rare earth elements) and electrolyte adjuvant alkali metal sulfates are heated in an aqueous solution for several hours, followed by high-temperature calcination in a tube furnace for several hours (a muffle furnace can also be used, and an air atmosphere can be used) to obtain rare earth upconversion luminescent materials with enhanced luminescence.

[0091] The present invention provides the application of metal sulfates in the preparation of rare-earth upconversion luminescent materials and a method for preparing rare-earth upconversion luminescent materials enhanced by electrolyte adjuvants. Specifically, the present invention applies alkali metal sulfates and / or alkaline earth metal sulfates in the preparation of rare-earth upconversion luminescent materials, enhancing luminescence performance without significantly affecting the crystal phase and composition. The present invention also provides a corresponding method for preparing rare-earth upconversion luminescent materials enhanced by electrolyte adjuvants. This method uses alkali metal or alkaline earth metal sulfates as electrolyte adjuvants, requires almost no post-processing, and does not affect the original crystal structure and proportions. The entire process involves only water, a green solvent, resulting in low cost and ease of mass production.

[0092] The method for preparing rare-earth upconversion luminescent materials enhanced by electrolyte adjuvants provided by this invention is a novel strategy for enhancing rare-earth upconversion luminescence. It can significantly improve upconversion luminescence with remarkable enhancement effect. Moreover, the enhanced luminescence does not significantly affect the crystal phase and composition, and has good repeatability. At the same time, the method is simple and only uses water as a green solvent, which is conducive to industrial mass production and has good application prospects and potential economic benefits.

[0093] Experimental results show that, with Y 1.6 Yb 0.3 Er 0.1 Taking O3 crystals as an example, electrolyte adjuvants can enhance upconversion luminescence by 10.7 times.

[0094] To further illustrate the present invention, the following detailed description of a rare earth luminescent material, its preparation method, and its application is provided in conjunction with embodiments. However, it should be understood that these embodiments are implemented under the premise of the technical solution of the present invention, and detailed implementation methods and specific operating procedures are given only to further illustrate the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention. The scope of protection of the present invention is not limited to the following embodiments.

[0095] Example 1

[0096] YCl3, YbBr3, ErI3, and Na2SO4 were dissolved together in 32 mL of deionized water at a molar ratio of 0.8:0.15:0.05:1. The solution was then heated to 80 °C. O The reaction was heated at C for 12 hours, then transferred to a tube furnace and heated at 1250°C under an argon atmosphere. O Calcination with C for 12 hours, followed by natural cooling to room temperature, yields Y with enhanced upconversion luminescence. 1.6 Yb 0.3 Er 0.1 O3 crystals. Compared with crystals obtained without the introduction of the electrolyte adjuvant Na2SO4, its crystal phase structure remained unchanged. X-ray powder diffraction results are shown in the attached figure. Figure 1 As shown, inductively coupled plasma atomic emission spectroscopy (ICP-AES) testing revealed that its composition remained almost unchanged. Figure 2 The upconversion fluorescence spectrum of the crystal under 980 nm near-infrared light excitation was shown, with a 10.7-fold enhancement in green light emission and a 7.1-fold enhancement in red light emission.

[0097] Example 2

[0098] Lu(NO3)3, (CH3COO)3Yb, TmCl3, and BaSO4 were dissolved together in 13 mL of deionized water at a molar ratio of 1:0.11:0.001:0.75. The solution was then heated to 136 mL. O The reaction was heated at C for 2 hours, then transferred to a tube furnace and heated at 1050 °C under a nitrogen atmosphere. O Calcination with C for 7 hours, followed by natural cooling to room temperature, yields Lu with enhanced upconversion luminescence. 1.78 Yb 0.2 Tm 0.02 O3 crystals. Figure 3 The upconversion fluorescence spectrum of the crystal under 980 nm near-infrared light excitation was shown, and the blue light emission was enhanced by 7.6 times compared with the crystal obtained without introducing the electrolyte adjuvant BaSO4.

[0099] Example 3

[0100] Sc2(SO4)3, Yb2(CO3)3, HoF3, and Cs2SO4 were dissolved together in 6.5 mL of deionized water at a molar ratio of 1:0.25:0.025:0.5. O The reaction was heated at C for 20 hours, then transferred to a tube furnace and heated at 1400°C in an air atmosphere. O Calcination with C for 1 hour, followed by natural cooling to room temperature, yields Sc with enhanced upconversion luminescence. 1.56 Yb 0.4 Ho 0.04 O3 crystals. Figure 4 The upconversion fluorescence spectrum of the crystal under 980 nm near-infrared light excitation was shown. Compared with the crystal obtained without the introduction of electrolyte adjuvant Cs2SO4, the green light emission was enhanced by 6.6 times and the red light emission was enhanced by 6.8 times.

[0101] Example 4

[0102] ErCl3 and Na2SO4 were dissolved together in 13.8 mL of deionized water at a molar ratio of 1:2, and the solution was heated at 47 °C. O The reaction was heated at C for 15.5 hours, then transferred to a tube furnace and heated at 1800°C in an air atmosphere. O Calcination at C for 4 hours, followed by natural cooling to room temperature, yields Er₂O₃ crystals with enhanced upconversion luminescence.3+ Classic red light emission can be enhanced by 3 times.

[0103] Comparative Example 1

[0104] YI3, YbBr3, ErI3, and NaNO3 were dissolved together in 10 mL of deionized water at a molar ratio of 0.8:0.15:0.05:1. The solution was then heated at 80 °C. O The reaction was heated at C for 3 hours, then transferred to a tube furnace and heated at 1000 °C under an argon atmosphere. O C was calcined for 10 hours and then naturally cooled to room temperature to obtain Y. 1.6 Yb 0.3 Er 0.1 Compared to the case without the introduction of the electrolyte adjuvant NaNO3, the upconversion luminescence of O3 crystals showed no improvement.

[0105] Comparative Example 2

[0106] Dissolve (CH3COO)3La, Yb(NO3)3, Ho2(SO4)3, and (NH4)2SO4 in 3 mL of deionized water at a molar ratio of 1:0.2:0.03:4. (The solution was then dissolved at 126 °C.) O The reaction was heated at C for 4 hours, then transferred to a tube furnace and heated at 800°C under a nitrogen atmosphere. O Calcination with C for 4 hours, followed by natural cooling to room temperature, yields La 1.63 Yb 0.32 Ho 0.05 Compared to the case without the introduction of the electrolyte adjuvant (NH4)2SO4, the upconversion luminescence of O3 crystals not only did not achieve any enhancement, but also tended to weaken.

[0107] Comparative Example 3

[0108] GdCl3, YbCl3, TmCl3, and Li2SO4 were dissolved together in 6 mL of deionized water at a molar ratio of 1:0.02:0.04:0.5. The solution was then heated to 94 °C. O The reaction was heated at C for 5 hours, then transferred to a tube furnace and heated at 600°C under a hydrogen chloride atmosphere. O After calcining at C for 2 hours and naturally cooling to room temperature, the resulting crystals were a mixed phase, and no upconversion luminescence enhancement phenomenon was observed.

[0109] The foregoing has provided a detailed description of a rare-earth luminescent material and its preparation method, as well as its application in ratiometric fluorescence detection. Specific examples have been used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely illustrative of the method and core ideas of the invention, including the best mode, and are intended to enable any person skilled in the art to practice the invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims. The scope of protection of this patent is defined by the claims and may include other embodiments conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the wording of the claims, or if they include equivalent structural elements that are not substantially different from the wording of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. A method for preparing electrolyte adjuvant enhanced rare earth upconversion luminescent material, characterized in that, The method comprises the following steps: 1) heating and reacting a rare earth salt and an electrolyte adjuvant metal sulfate in water, and then high-temperature calcining to obtain a rare earth upconversion luminescent material; The high-temperature calcining temperature is 800-2000 ℃; The high-temperature calcining time is 0.5-120 h; The high-temperature calcining atmosphere comprises one or more of nitrogen, inert gas and air; The general formula of the rare earth upconversion luminescent material is RE 2-x-y Yb x Ln y O3; 0≤x≤2, 0 The rare earth element in the rare earth salt is RE and Ln, or RE, Ln and Yb; The RE is selected from one or more of Sc, Y, La, Gd and Lu; The Ln is selected from one or more of Ho, Er and Tm; The metal sulfate is barium sulfate; The addition of the metal sulfate does not affect the original crystal structure of the rare earth upconversion luminescent material.

2. The production method according to claim 1, characterized by, The rare earth salt comprises one or more of a rare earth halide, a rare earth nitrate, a rare earth acetate, a rare earth carbonate and a rare earth sulfate.

3. The preparation method according to claim 1, characterized in that, The reaction temperature is 30-180 ℃.

4. The production method according to claim 1, characterized by, The reaction time is 1-240 h.

5. Application of the preparation method of any one of claims 1-4 in the preparation of a rare earth upconversion luminescent material; The application is specifically an application of increasing luminescent performance.

6. Use according to claim 5, characterized in that, In the application process, the addition of the metal sulfate does not affect the original proportioning of the crystal of the rare earth upconversion luminescent material.

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