CN109081694B

CN109081694B - Yttrium aluminum composite oxide nano powder synthesized by precursor liquid and high-temperature atomized flame and preparation method thereof

Info

Publication number: CN109081694B
Application number: CN201810908788.4A
Authority: CN
Inventors: 李水清; 田辉; 卫吉丽; 任翊华; 卓建坤
Original assignee: Tsinghua University
Current assignee: Tsinghua University
Priority date: 2018-08-10
Filing date: 2018-08-10
Publication date: 2021-06-22
Anticipated expiration: 2038-08-10
Also published as: CN109081694A

Abstract

The invention provides a preparation method of yttrium aluminum composite oxide nano powder synthesized by high-temperature atomizing flame, which comprises the following steps: atomizing the precursor solution to form a liquidA drop, the precursor liquid comprising Y³⁺And Al³⁺Inorganic salts, additives and organic solvents of (a); and introducing the liquid drops into flame for reaction to generate yttrium aluminum composite oxide nano powder, wherein the additive is used for reacting with the Y³⁺And Al³⁺Under the action of the flame, the inorganic salt generates a volatilization temperature lower than that of the Y in the liquid drops formed by the precursor liquid³⁺And Al³⁺Of inorganic salts of (b), thereby increasing the Y³⁺And Al³⁺The volatility of the inorganic salt in the flame. The invention also provides yttrium aluminum composite oxide nano powder synthesized by high-temperature atomizing flame and precursor liquid.

Description

Yttrium aluminum composite oxide nano powder synthesized by precursor liquid and high-temperature atomized flame and preparation method thereof

Technical Field

The invention belongs to the field of synthesis of structural and functional ceramic material nano powder, and particularly relates to a precursor liquid, yttrium aluminum composite oxide nano powder synthesized by high-temperature atomizing flame prepared by using the precursor liquid and a preparation method.

Background

Yttrium aluminum garnet (Y)₃Al₅O₁₂YAG) belongs to a cubic crystal system, has stable physical and chemical properties, and the characteristics enable the YAG to be widely applied to the fields of structures, functional materials and the like, for example, the YAG fluorescent material is prepared into transparent ceramic to be used as an LED backlight source and a packaging material; the YAG down-conversion luminescent material can effectively improve the photoelectric conversion efficiency of the solar cell; polycrystalline YAG is expected to replace single crystal materials and become a new generation of laser materials. In addition, the transparent nature of YAG in the 0.2 to 5 μm band makes it a new infrared window and fairing material. Currently, the YAG ceramics or powders are mainly synthesized by solid-phase synthesis, coprecipitation, hydrothermal method, sol-gel method, flame spray pyrolysis, gas-phase flame synthesis, and the like.

The comparative research shows that the YAG ceramic material prepared by the solid-phase reaction method has high reaction temperature and long time, and is easy to generate intermediate terms, which is one of the most main factors influencing the material performance; the coprecipitation method has too long period for preparing the powder and the reaction is not easy to control; the efficiency of preparing powder by a hydrothermal method is low; the precursors prepared by the sol-gel method are difficult to wash and the precursors (metal organic salts) are expensive. The flame synthesis method for preparing the nano powder has the advantages of simple process, short reaction time and easy formation. In addition, element substitution and doping are commonly used effective means for improving physical, chemical and mechanical properties of various metal oxide materials. However, the percentage of elemental substitution and doping, and the uniformity of doping, are difficult to control precisely when using conventional synthesis methods. The flame synthesis method utilizes the reaction of the precursor solution in flame, not only can quickly synthesize the high-purity micro/nano metal oxide material, but also can accurately realize element substitution or doping. In addition, flame synthesis has gained widespread attention due to the simplicity of equipment, continuous production, high throughput, and the ability to obtain dense spherical particles.

In recent years, the industrial demand for a large number of novel nano-functional materials has driven the flame synthesis technology to continuously make new breakthroughs in the last decade. The precursor is developed from gas phase feeding to liquid phase feeding, and the synthesized product is also developed from single oxide to multi-element doping component. At present, how to adopt a liquid phase precursor to realize the gas phase synthesis of nano powder with uniform particles and even controllable size by high-temperature atomization flame, especially nano multi-element powder of two or more metals, has become a 'neck' problem with great application value on the international technological frontier level. The patent documents of W, J, Schtach publication, namely 'metal oxide produced by flame spray pyrolysis method' (publication No. CN1665743A) and the article published by yellow Shandong et al, namely 'rare earth oxide synthesized by flame spray pyrolysis method', and the patent documents of W, J, Schtach publication, and the like, wherein the precursors in 125-136-Si-136 are metal organic compounds, not only have higher production cost, but also lack regulation and control on the combustion synthesis reaction process. The article published by the methods of flame spray pyrolysis and the like for preparing nanocrystalline magnesia-alumina spinel powder, refractory materials 2007,41(5):369-372 adopts inorganic nitrate as a precursor, and a precursor solution is a mixed solution of ethanol and distilled water, so that the cost is reduced, but the particle size distribution of the synthesized powder particles is wide. The above researches only prepare related materials by a preliminary flame spray pyrolysis method, and the powder obtained by YAG synthesis has the problems of non-uniform particles and difficult control of the size, and nano-scale spherical particles with uniform size are difficult to obtain.

Disclosure of Invention

Therefore, a precursor solution, yttrium aluminum composite oxide nano powder synthesized by using high-temperature atomizing flame prepared by using the precursor solution and a preparation method are needed.

A preparation method for synthesizing yttrium aluminum composite oxide nano powder by high-temperature atomizing flame comprises the following steps:

atomizing a precursor liquid to form droplets, the precursor liquid comprising Y³⁺And Al³⁺Inorganic salts, additives and organic solvents of (a); and

introducing the liquid drops into flame for reaction to generate yttrium aluminum composite oxide nano powder,

wherein the additive is used for reacting with the Y³⁺And Al³⁺Under the action of the flame, the inorganic salt generates a volatilization temperature lower than that of the Y in the liquid drops formed by the precursor liquid³⁺And Al³⁺Of inorganic salts of (b), thereby increasing the Y³⁺And Al³⁺The volatility of the inorganic salt in the flame.

In one embodiment, the volatilization temperature is lower than that of Y under the action of the additive³⁺And Al³⁺The inorganic salt substance is completely evaporated in flame and converted into gas phase, and the gas phase is nucleated and grown to generate the yttrium aluminum composite oxide nano powder.

In one embodiment, the additive contains a carboxylic acid group capable of reacting with the Y³⁺And Al³⁺Is used to form Y in the droplets formed from the precursor liquid³⁺And Al³⁺A carboxylic acid salt of (1).

In one embodiment, the additive comprises at least one of 2-ethylhexanoic acid, citric acid, naphthenic acid, and neodecanoic acid.

In one embodiment, the mass fraction of the additive in the precursor liquid is 5% to 50%.

In one embodiment, the mass fraction of the additive in the precursor liquid is 18% to 30%.

In one embodiment, the organic solvent has an enthalpy of combustion greater than 20 kJ/ml.

In one embodiment, the organic solvent comprises at least one of methanol, ethanol, n-butanol, and isopropanol.

In one embodiment, the precursor solution further comprises water miscible with the organic solvent.

In one embodiment, Y is³⁺And Al³⁺The inorganic salt of (A) includes Y³⁺And Al³⁺At least one of nitrate, fluoride, chloride, bromide, iodide and carbonate.

In one embodiment, the precursor solution further comprises an inorganic salt of a dopant metal ion comprising Yb³⁺、Nd³⁺、Ce³⁺And Eu³⁺At least one of (1).

In one embodiment, the total concentration of the metal ions in the precursor solution is 0.16-0.8 mol/L.

In one embodiment, the flame has a temperature of 1200 ℃ to 1900 ℃.

A high-temp atomized flame synthesized nano-class yttrium-aluminium composite oxide powder with average grain diameter of 20-30 nm.

In one embodiment, the material for synthesizing yttrium aluminum composite oxide nano-powder by high-temperature atomizing flame comprises Y₃Al₅O₁₂And M is Y₃Al₅O₁₂M is a trivalent metal cation.

In one embodiment, M is Yb³⁺、Nd³⁺、Ce³⁺And Eu³⁺At least one of (1).

In one embodiment, the particle size distribution is 20 nm to 30 nm.

In one embodiment, the particle size distribution satisfies D₉₅-D₅Less than or equal to 10 nanometers.

A precursor liquid for high-temp atomizing flame synthesizing yttrium aluminium composite oxideA nano-powder, the precursor liquid comprises Y³⁺And Al³⁺Inorganic salt of (a), an additive for increasing the Y, and an organic solvent³⁺And Al³⁺The volatility of the inorganic salt in the flame.

The precursor solution for synthesizing yttrium aluminum composite oxide nano powder by high-temperature atomizing flame is added to improve Y³⁺And Al³⁺The volatile additive of inorganic salt in flame is combined with inorganic salt and organic solvent simultaneously, the evaporation process in the liquid-phase feeding atomization flame synthesis process is actively controlled, the synthesis path in the flame field is controlled to be single 'gas phase-particle', the coexistence of two synthesis paths of 'liquid phase-particle' and 'gas phase-particle' is avoided, the problem of uneven particle size is solved by controlling the synthesis path, the prepared yttrium aluminum composite oxide nano powder has more accurate chemical components, nanometer spherical particle morphology and uniform particle size. In addition, the method has the advantages of simple related raw materials and equipment, high synthesis speed and safe process, and is suitable for large-scale industrial utilization.

Drawings

FIG. 1 is a flow chart of a method for preparing yttrium aluminum composite oxide nano-powder by high-temperature atomization flame synthesis according to an embodiment of the invention;

FIG. 2 is a schematic diagram of the mechanism of initial particle formation and coalescence growth during flame synthesis;

FIG. 3 is a Transmission Electron Microscope (TEM) photograph of yttrium aluminum composite oxide nanopowder synthesized by high temperature atomized flame in example 1 of the present invention;

FIG. 4 is a TEM photograph of yttrium aluminum composite oxide nanopowder synthesized by high temperature atomized flame of example 2 of the present invention;

FIG. 5 is a TEM photograph of a high temperature atomized flame synthesized yttrium aluminum composite oxide nanopowder of comparative example 1 of the present invention;

FIG. 6 is a TEM photograph of a high temperature atomized flame synthesized yttrium aluminum composite oxide nanopowder of comparative example 2 of the present invention;

FIG. 7 is a TEM photograph of a high temperature atomized flame synthesized yttrium aluminum composite oxide nanopowder of comparative example 3 of the present invention;

FIG. 8 is a TEM photograph of a high temperature atomized flame synthesized yttrium aluminum composite oxide nanopowder of comparative example 4 of the present invention;

FIG. 9 is an energy spectrum analysis (EDS) element distribution diagram of yttrium aluminum composite oxide nanopowder synthesized by high temperature atomization flame in example 3 of the invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, an embodiment of the present invention provides a method for synthesizing yttrium aluminum composite oxide nano-powder by high-temperature atomizing flame, including:

s1, atomizing a precursor liquid to form liquid drops, wherein the precursor liquid comprises Y³⁺And Al³⁺Inorganic salts, additives and organic solvents of (a); and

and S2, introducing the liquid drops into flame for reaction to generate yttrium aluminum composite oxide nano powder.

The additive is used for reacting with the Y³⁺And Al³⁺Under the action of the flame, the inorganic salt generates a volatilization temperature lower than that of the Y in the liquid drops formed by the precursor liquid³⁺And Al³⁺Of inorganic salts of (b), thereby increasing the Y³⁺And Al³⁺The volatility of the inorganic salt in the flame.

Referring to fig. 2, different types of precursors determine the synthesis and growth path of the following nanoparticles, and the synthesis and growth of the nanoparticles in the flame field undergo initial particle formation and the formation of nanoparticles by collision-coalescence of the initial particles. The gas phase precursor forms product steam through physical or chemical reaction, and then is converted into nano particles through a nucleation path, namely the process of 'gas phase-particle' conversion. Liquid phase precursor passingAtomizing to form atomized liquid drops, evaporating the atomized liquid drops in a flame field to convert the atomized liquid drops into a gas phase, and converting the gas phase into nano particles through a gas phase path; or converted into nanoparticles through evaporation deposition, interparticle interaction and other ways. This process is extremely complex and must take into account variations within the droplet/particle and direct conversion of "droplet-particle" into account. The inventor finds out through extensive research that the liquid phase feeding atomization flame gas phase synthesis method for ensuring the conversion path of 'gas phase-particle' is the key for obtaining nano-scale particles with uniform size. The inventor adds the precursor solution to improve Y³⁺And Al³⁺The volatile additive of inorganic salt in flame is combined with inorganic salt and organic solvent simultaneously, the evaporation process in the liquid-phase feeding atomization flame synthesis process is actively controlled, the synthesis path in the flame field is controlled to be single 'gas phase-particle', the coexistence of two synthesis paths of 'liquid phase-particle' and 'gas phase-particle' is avoided, the problem of uneven particle size is solved by controlling the synthesis path, the prepared yttrium aluminum composite oxide nano powder has more accurate chemical components, nanometer spherical particle morphology and uniform particle size. In addition, the method has the advantages of simple related raw materials and equipment, high synthesis speed and safe process, and is suitable for large-scale industrial utilization.

Specifically, by controlling Y in the precursor liquid³⁺And Al³⁺The chemical components of the yttrium aluminum composite oxide nano powder can be accurately controlled according to the stoichiometric ratio. In one embodiment, the yttrium aluminum composite oxide nanopowder is preferably doped or undoped yttrium aluminum garnet (Y)₃Al₅O₁₂YAG) nanopowder.

In the precursor liquid, the Y³⁺And Al³⁺The inorganic salt and the additive are dispersed or dissolved in the organic solvent and are uniformly mixed. Said Y is³⁺And Al³⁺The inorganic salt of (3) is preferably at least one of a nitrate salt, a fluoride salt, a chloride salt, a bromide salt, an iodide salt and a carbonate salt. Nitrates such as yttrium nitrate and aluminum nitrate are preferred. The nitrate raw material for preparing the precursor liquid may be, for example, yttrium nitrate hexahydrate (Y (NO)₃)₃·6H₂O) and aluminum nitrate nonahydrate (Al (NO)₃)₃·9H₂O)。

In some embodiments, the precursor liquid further comprises an inorganic salt of a dopant metal ion comprising Yb³⁺、Nd³⁺、Ce³⁺And Eu³⁺At least one of (1). The product synthesized by using the precursor solution of the inorganic salt doped with metal ions is doped yttrium aluminum composite oxide nano powder, such as doped yttrium aluminum garnet, and the doped elements are uniformly distributed in the nano powder. The inorganic salt doped with metal ions is preferably at least one of nitrate, fluorine salt, chlorine salt, bromine salt, iodine salt and carbonate. Preferably, the inorganic salt doped with a metal ion is mixed with Y³⁺And Al³⁺The inorganic salts of (a) are inorganic salts of the same kind, i.e. the anions are the same. More preferably, the inorganic salt doped with metal ions is a nitrate of the doped metal. The additive is also used for generating a substance with a volatilization temperature lower than that of the inorganic salt doped with the metal ions in the liquid drops formed by the precursor liquid under the action of the flame, so that the volatility of the inorganic salt doped with the metal ions in the flame is improved.

The additive is used for increasing Y³⁺And Al³⁺And/or the volatility of the inorganic salt of the doping metal ion in the flame, in particular, the additive is capable of reacting with the Y³⁺And Al³⁺And/or inorganic salt doped with metal ions in the flame to produce a volatile temperature lower than that of Y³⁺And Al³⁺The inorganic salt of (1). In one embodiment, the Y is³⁺And Al³⁺The additive contains a carboxylic acid group capable of reacting with said Y³⁺And Al³⁺In a flame to form Y³⁺And Al³⁺A carboxylic acid salt of (1). Y is³⁺And Al³⁺The volatilization temperature of the carboxylic acid salt of (A) is lower than that of Y³⁺And Al³⁺Thereby increasing Y during the flame synthesis³⁺And Al³⁺Volatility of the nitrate salt of (a). In one embodiment, the inorganic salt doped with metal ions is nitrateSaid additive containing carboxylic acid groups capable of forming carboxylate salts of the doped metal ions in the flame with said inorganic salt of the doped metal ions. The carboxylate doped with the metal ions has a lower volatilization temperature than the nitrate doped with the metal ions, thereby increasing the volatility of the nitrate doped with the metal ions during the flame synthesis process.

In one embodiment, the additive comprises at least one of 2-ethylhexanoic acid, citric acid, naphthenic acid, neodecanoic acid. The mass fraction of the additive in the precursor liquid is preferably 5% to 50%, more preferably 18% to 30%.

The organic solvent is preferably one capable of dissolving the Y³⁺And Al³⁺And/or inorganic salts doped with metal ions, and the additives mentioned, depending on Y³⁺And Al³⁺The inorganic salt and/or the inorganic salt doped with metal ions of (3) and the specific material of the additive are selected, and preferably at least one of methanol, ethanol, n-butanol and isopropanol is included. In one embodiment, the precursor liquid may further include water, and the organic solvent is miscible with water. Metal ions, e.g. Y³⁺And Al³⁺Or Y³⁺And Al³⁺And the total concentration of the doped ions in the precursor liquid is preferably 0.16-0.8 mol/L.

In the precursor liquid, the organic solvent is used as a combustion agent to provide heat in the flame synthesis process, so that the flame temperature is adjusted. Preferably, the organic solvent has a enthalpy of combustion greater than 20 kJ/ml. In order to make the reaction path easier to control in flame synthesis, in the precursor liquid, other combustion energy sources except organic solvent are basically excluded, and only inorganic salt is preferably used as Y³⁺And Al³⁺So that the synthetic path can be easily controlled, on the basis of which the adjustable Y is adopted³⁺And Al³⁺The volatile additives of (1) allow the synthesis route to be controlled as a single "gas phase-particle". Preferably, under the action of the additive, the liquid drops are completely converted into gas phase in flame, and the gas phase is nucleated and grown to generate the yttrium aluminum composite oxide nano powder.

In step S2, the step of introducing the droplets into the flame for oxidation reaction includes the steps of atomizing the precursor liquid into droplets and introducing the droplets into the burner. The liquid drops formed by the precursor liquid are directly synthesized into yttrium aluminum composite oxide nano powder in the flame of a burner. The temperature of the flame is preferably controlled to be 1200 to 1900 ℃. In one embodiment, the combustion flame is formed by combustion of methane in an oxygen-rich environment, preferably in a 1:3 volume ratio of methane to oxygen.

The embodiment of the invention also provides yttrium aluminum composite oxide nano powder synthesized by high-temperature atomizing flame. Preferably, the material of yttrium aluminum composite oxide nano powder comprises Y₃Al₅O₁₂And M is Y₃Al₅O₁₂M is a trivalent metal cation. More preferably, M is Yb³⁺、Nd³⁺、Ce³⁺And Eu³⁺At least one of (1).

The average grain diameter of the yttrium aluminum composite oxide nano powder is 20 to 30 nanometers. Specifically, the particle size distribution of the yttrium aluminum composite oxide nano powder is 20 to 30 nanometers. Preferably, the particle size distribution of the yttrium aluminum composite oxide nano powder meets D₉₅-D₅Less than or equal to 10 nanometers, namely, has narrower particle size distribution.

Example 1

Using yttrium nitrate hexahydrate (Y (NO)₃)₃·6H₂O) and aluminum nitrate nonahydrate (Al (NO)₃)₃·9H₂O) is a precursor, the precursor is dissolved in pure ethanol, the additive is 2-ethyl caproic acid, and the mass fraction of the additive in the precursor liquid is 50%. Preparing solution according to stoichiometric ratio, Y in precursor solution³⁺:Al³⁺3:5, Y in the precursor solution³⁺And Al³⁺The total concentration of (2) is 0.4 mol/L. Atomizing the precursor liquid, and feeding the atomized precursor liquid into flame of a burner to obtain YAG spherical nano-particle powder.

Example 2

Example 2 is the same as example 1 except that the additive 2-ethylhexanoic acid has a mass fraction of 18% in the precursor liquid.

Referring to fig. 3 and 4, it can be seen that, since the synthesis path of the atomized precursor liquid in the flame is controlled to be "gas phase-particle", the particle sphericity of the nano-powder obtained in examples 1 and 2 is good, and the nano-powder has a narrow particle size distribution.

Comparative example 1

Comparative example 1 is the same as example 1 except that there is no additive in the precursor solution.

Referring to fig. 5, it can be seen that the particle size of the powder obtained in comparative example 1 is larger, and the synthesis path of the atomized precursor liquid in the flame field still has a "droplet-particle" path.

Comparative example 2

Using yttrium nitrate hexahydrate (Y (NO)₃)₃·6H₂O) and aluminum nitrate nonahydrate (Al (NO)₃)₃·9H₂O) is used as a precursor, is dissolved in pure deionized water, has no additive, and is prepared into solution according to the stoichiometric ratio, and Y is contained in the precursor solution³⁺:Al³⁺3:5, Y in the precursor solution³⁺And Al³⁺The total concentration of (2) is 0.16 mol/L. The precursor liquid is atomized and enters flame of a burner to obtain YAG spherical particle powder.

Comparative example 3

Comparative example 3 is the same as comparative example 2, except that Y is present only in the precursor solution³⁺And Al³⁺The total concentration of (2) is 0.4 mol/L.

Comparative example 4

Comparative example 4 is the same as comparative example 2, except that Y is present only in the precursor solution³⁺And Al³⁺The total concentration of (2) is 0.8 mol/L.

Referring to fig. 6 to 8, in comparative examples 2 to 4, since the synthesis path of the atomized precursor liquid in the flame has a "droplet-particle" path, the obtained powder has a larger particle size and a non-uniform size distribution.

Example 3

Using yttrium nitrate hexahydrate (Y (NO)₃)₃·6H₂O), aluminum nitrate nonahydrate (Al (NO)₃)₃·9H₂O) and ytterbium nitrate pentahydrate Yb (NO)₃)₃·5H₂O is a precursor, Yb is a doping element, and the precursor is dissolved in a mixed solvent of deionized water and n-butanol, and waterN-butanol was 3:1 (volume ratio). The additive is citric acid, and the mass fraction of the additive in the precursor liquid is 5%. Preparing solution according to stoichiometric ratio, and Yb in the precursor solution³⁺:(Y³⁺+Al³⁺) 0.05, Y in the precursor solution³⁺And Al³⁺The total concentration of (2) is 0.4 mol/L. The precursor liquid is atomized and enters flame of a burner to obtain the Yb-YAG doped spherical nano-particle powder with the concentration of 5 percent.

Referring to fig. 9, it can be seen that each element is uniformly distributed in the product nanoparticle powder, and the synthesis path of the atomized precursor liquid in the flame is "gas phase-particle".

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A preparation method for synthesizing yttrium aluminum composite oxide nano powder by high-temperature atomizing flame is characterized by comprising the following steps:

wherein the additive is used for reacting with the Y³⁺And Al³⁺Under the action of the flame, the inorganic salt generates a volatilization temperature lower than that of the Y in the liquid drops formed by the precursor liquid³⁺And Al³⁺Of inorganic salts of (b), thereby increasing the Y³⁺And Al³⁺Is volatile in the flame, the additive being citric acid, capable of reacting with the Y³⁺And Al³⁺Is used to form Y in the droplets formed from the precursor liquid³⁺And Al³⁺A carboxylic acid salt of (1).

2. The method for preparing yttrium aluminum composite oxide nano-powder by high-temperature atomized flame synthesis according to claim 1, wherein the volatilization temperature is lower than that of Y under the action of the additive³⁺And Al³⁺The inorganic salt substance is completely evaporated in flame and converted into gas phase, and the gas phase is nucleated and grown to generate the yttrium aluminum composite oxide nano powder.

3. The method for preparing yttrium aluminum composite oxide nano-powder through high-temperature atomized flame synthesis according to claim 1, wherein the mass fraction of the additive in the precursor liquid is 5-50%.

4. The method for preparing yttrium aluminum composite oxide nano-powder through high-temperature atomized flame synthesis according to claim 1, wherein the mass fraction of the additive in the precursor liquid is 18-30%.

5. The method for preparing yttrium aluminum composite oxide nano-powder by high-temperature atomized flame synthesis according to claim 1, wherein the combustion enthalpy of the organic solvent is more than 20 kJ/ml.

6. The method for preparing yttrium aluminum composite oxide nano-powder through high-temperature atomizing flame synthesis according to claim 1, wherein the organic solvent comprises at least one of methanol, ethanol, n-butanol and isopropanol.

7. The method for preparing yttrium aluminum composite oxide nanopowder by high-temperature atomizing flame synthesis according to claim 1, wherein the precursor solution further comprises water miscible with the organic solvent.

8. The method for preparing yttrium aluminum composite oxide nano-powder by high-temperature atomized flame synthesis according to claim 1, wherein Y is³⁺And Al³⁺The inorganic salt of (A) includes Y³⁺And Al³⁺At least one of nitrate, fluoride, chloride, bromide, iodide and carbonate.

9. The method for preparing yttrium aluminum composite oxide nanopowder by high-temperature atomizing flame synthesis according to claim 1, wherein the precursor solution further comprises an inorganic salt doped with metal ions, and the doped metal ions comprise Yb³⁺、Nd³⁺、Ce³ ⁺And Eu³⁺At least one of (1).

10. The method for preparing yttrium aluminum composite oxide nano-powder through high-temperature atomizing flame synthesis according to claim 1 or 9, wherein the total concentration of metal ions in the precursor solution is 0.16-0.8 mol/L.

11. The method for preparing yttrium aluminum composite oxide nano-powder by high-temperature atomization flame synthesis according to claim 1, wherein the temperature of the flame is 1200-1900 ℃.

12. The precursor liquid is used for synthesizing yttrium aluminum composite oxide nano powder by high-temperature atomizing flame, and is characterized by comprising Y³⁺And Al³⁺The additive is used for mixing with the Y, and an organic solvent³⁺And Al³⁺Under the action of the flame, the inorganic salt generates a volatilization temperature lower than that of the Y in the liquid drops formed by the precursor liquid³⁺And Al³⁺Of inorganic salts of (b), thereby increasing the Y³⁺And Al³⁺Is volatile in the flame, the additive being citric acid capable of reacting withSaid Y is³⁺And Al³⁺Is used to form Y in the droplets formed from the precursor liquid³⁺And Al³⁺A carboxylic acid salt of (1).