Preparation method of monodisperse spherical yttrium oxide with controllable granularity

Abstract

The invention discloses a preparation method of monodisperse spherical yttrium oxide with controllable granularity, and relates to the field of rare earth materials. The preparation method of the monodisperse spherical yttrium oxide with controllable granularity comprises the following steps: S1, uniformly stirring and mixing an alcoholic solution of triethanolamine and ammonia water to prepare a mixed precipitant solution; s2, slowly adding the yttrium nitrate solution into the mixed precipitant solution at 60-80 DEG C, aging after adding, filtering, and washing with deionized water to obtain a precursor precipitate; and S3, uniformly stirring and mixing 1, 2-propylene glycol, the precursor precipitate and a surfactant, carrying out high-temperature and high-pressure reaction, filtering, washing, drying and roasting to obtain the spherical yttrium oxide. The spherical yttrium oxide particles prepared by the method are good in dispersity and free of agglomeration phenomenon; the particle size is uniform and controllable, and the particle size distribution range is narrow.

Description

Technical Field

[0001] The present invention relates to the field of rare earth materials, and specifically relates to a preparation method of monodisperse spherical yttrium oxide with controllable particle size. Background Art

[0002] Nano yttrium oxide (Y2O3) is an important rare earth nanomaterial. Compared with traditional materials, it has unique physical and chemical properties, showing extensive application value in many fields such as fluorescent materials and advanced ceramics. Yttrium oxide nanospheres have characteristics such as higher specific surface area, surface atom number, surface energy, and better dispersibility, which will greatly improve their optical, electrical, magnetic, mechanical, and chemical properties. The main methods for preparing nano yttrium oxide include sol-gel method, hydrothermal synthesis method, combustion method, electrochemical method, precipitation method, etc.

[0003] Due to the large surface energy of nanoparticles, the particles are in an unstable state and are prone to agglomeration, losing the characteristics of nanoparticles, which seriously affects the application of nanomaterials. By designing synthesis methods and combining different surfactants, the controllable synthesis of the morphology of yttrium oxide powder is realized, while ensuring its good dispersibility and uniformity, which has important scientific significance and application value for the customized preparation of powder morphology.

[0004] The Chinese patent application with the publication number CN118145693A discloses a method for preparing yttrium oxide powder. In this invention, an aqueous solution of yttrium salt and an alkali metal hydroxide are subjected to a precipitation reaction under the condition of pH = 7 - 14; the above reaction mixture is subjected to a hydrothermal reaction at a temperature of 160 - 200 °C to obtain a precursor; the precursor is preheated at a temperature of 200 - 300 °C and then calcined at a temperature of 800 - 900 °C to obtain yttrium oxide powder. The method of this invention prepares yttrium oxide powder with different morphologies and crystal structures by regulating the pH value of the reaction system, but this invention has limitations in the precise regulation of particle size distribution. Summary of the Invention

[0005] Aiming at the deficiencies of the existing technology, the purpose of the present invention is to provide a preparation method of monodisperse spherical yttrium oxide with controllable particle size.

[0006] To achieve the above purpose, the present invention is realized through the following technical solutions: A preparation method of monodisperse spherical yttrium oxide with controllable particle size, comprising the following steps: S1: Stir and mix an alcohol solution of triethanolamine and ammonia water to obtain a mixed precipitant solution; S2: Slowly add a yttrium nitrate solution to the mixed precipitant solution at 60 - 80 °C. After adding, age, filter, and wash with deionized water to obtain a precursor precipitate; S3: Stir 1,2 - propanediol, the precursor precipitate, and the surfactant evenly, conduct a reaction under high temperature and high pressure, filter, wash, dry, and calcine to obtain spherical yttrium oxide; The surfactant is prepared by the following method: N1: 2,6 - nonadien - 1 - ol reacts with octyl succinic anhydride to form an ester - group double - bond compound; the reaction equation is shown as follows:

[0007] N2: The ester - group double - bond compound reacts under the action of formic acid and 30wt% H2O2 to form an epoxy compound; the reaction equation is shown as follows:

[0008] N3: The epoxy compound reacts with 1 - (2 - hydroxyethyl) imidazole to form a tetramidazole compound; the reaction equation is shown as follows:

[0009] N4: The tetramidazole compound reacts with 1 - bromododecane to form a surfactant; the reaction equation is shown as follows:

[0010] In step N1, the feeding molar ratio of 2,6 - nonadien - 1 - ol to octyl succinic anhydride is 2:1; in step N2, the feeding mass ratio of the ester - group double - bond compound, formic acid, and 30wt% H2O2 is 10:6:9; in step N3, the feeding molar ratio of the epoxy compound to 1 - (2 - hydroxyethyl) imidazole is 1:5; in step N4, the feeding molar ratio of the tetramidazole compound to 1 - bromododecane is 1:4.5.

[0011] In step S1, the solvent in the alcoholic solution of triethanolamine is one of ethanol, n - butanol, and n - hexanol.

[0012] In step S1, the concentration of the alcoholic solution of triethanolamine is 1 - 2 mol / L, and the feeding volume ratio of ammonia water to the alcoholic solution of triethanolamine is (5 - 10):1.

[0013] In step S2, the concentration of the yttrium nitrate solution is 0.1 - 0.2 mol / L.

[0014] In step S2, the feeding molar ratio of triethanolamine in the mixed precipitant solution to yttrium nitrate in the yttrium nitrate solution is 10:(1 - 2).

[0015] In step S3, the feeding mass ratio of the precursor precipitate, the surfactant, and 1,2 - propanediol is 50:(5 - 15):(300 - 600).

[0016] In step S3, the high-temperature and high-pressure reaction temperature is 100 - 150 °C, the time is 12 - 24 h, and the pressure is 0.5 - 8.0 Mpa.

[0017] In step S3, the calcination temperature is 700 - 800 °C, and the time is 3 - 5 h.

[0018] Due to the above technical solutions, the beneficial effects of the present invention include: The surfactant prepared by the present invention is adsorbed on the surface of nanoparticles through electrostatic interaction, and micelles are formed under the action of hydrophobic long chains, providing a confined space for the growth of nanomaterials; the steric hindrance of the imidazole ring and the electrostatic repulsion of quaternary ammonium salts limit the growth space of nanomaterials, making the prepared spherical nano-yttrium oxide powder have a uniform morphology, good dispersibility and a narrow particle size distribution, and nano-yttrium oxide powder below 1000 nm can be controllably prepared. Description of the Drawings

[0019] Figure 1 High-resolution mass spectrum of the surfactant prepared in Example 1; Figure 2 Scanning electron microscope image of the spherical yttrium oxide prepared in Example 2; Figure 3 Scanning electron microscope image of the spherical yttrium oxide prepared in Example 3; Figure 4 Scanning electron microscope image of the spherical yttrium oxide prepared in Example 4; Figure 5 Scanning electron microscope image of the spherical yttrium oxide prepared in Example 5; Figure 6 Scanning electron microscope image of the spherical yttrium oxide prepared in Example 6; Figure 7 Scanning electron microscope image of the spherical yttrium oxide prepared in Example 7. Detailed Embodiments

[0020] The following is further described with reference to embodiments, but the present invention is not limited to these embodiments.

[0021] Example 1 Preparation of Surfactant: N1: Add 400 ml of toluene, 0.1 mol of n-octyl succinic anhydride, 0.2 mol of 2,6-nonadien-1-ol and 5 g of p-toluenesulfonic acid into a reaction flask, stir evenly, heat up to 100 °C, react for 7 h, separate the water generated during the reaction through a water separator, cool to room temperature, adjust the pH to 7 with saturated sodium bicarbonate solution, let it stand for layering, wash the organic phase three times with deionized water (200 ml each time), dry with 40 g of anhydrous magnesium sulfate, filter, and distill the organic phase under reduced pressure at 60 °C for 3 h to obtain an ester double bond compound; the nuclear magnetic resonance hydrogen spectrum data is as follows: 11H NMR (300 MHz, Chloroform- d ) δ 5.76 - 5.55 (m, 4H), 5.55 - 5.28 (m, 4H), 4.76 - 4.58 (m, 4H), 2.93 - 2.67 (m, 2H), 2.56 - 2.42 (m, 1H), 2.21 - 1.97 (m, 12H), 1.78 (dq, J = 13.8, 8.4 Hz, 1H), 1.62 - 1.16 (m, 13H), 1.02 - 0.79 (m, 9H); N2: 300 mL of DMF, 50 g of the ester group double bond compound, and 5 g of strong acid cation exchange resin were successively added to the reaction kettle, stirred and heated to 60 °C, and a mixed solution of 30 g of formic acid and 45 g of 30 wt% H2O2 was added dropwise. The addition was completed in 30 min, and the reaction was continued for 6 h. Then, it was distilled under reduced pressure at 60 °C for 3 h, washed three times with deionized water (300 mL each time), and vacuum dried at 50 °C for 10 h to obtain the epoxy compound; the 1H NMR data are as follows: 1 1H NMR (300 MHz, Chloroform- d ) δ 4.40 (dt, J = 11.4, 3.5 Hz, 2H), 4.15 (dt, J = 11.4, 3.5 Hz, 2H), 3.63 (dq, J = 4.7, 3.2 Hz, 2H), 3.34 (q, J = 4.7 Hz, 2H), 3.25 (q, J = 4.4 Hz, 2H), 3.13 - 3.02 (m, 2H), 2.94 - 2.67 (m, 2H), 2.48 (dd, J = 16.6, 8.7 Hz, 1H), 2.02 - 1.48 (m, 14H), 1.47 - 1.14 (m, 12H), 0.98 - 0.82 (m, 9H); N3: Under nitrogen protection, 600 mL of isopropanol, 0.1 mol of the epoxy compound, and 0.5 mol of 1-(2-hydroxyethyl)imidazole were successively added to the reaction kettle, stirred and mixed evenly, 10 g of tetraethylammonium bromide was added, and the temperature was raised to 70 °C for reaction for 4 h. After cooling, it was distilled under reduced pressure at 50 °C for 2 h, washed three times with deionized water (300 mL each time), and vacuum dried at 70 °C for 12 h to obtain the tetramidazole compound; the 1H NMR data are as follows: 11H NMR (300 MHz, Chloroform-d) δ 7.80 (tt, J = 1.7, 0.8 Hz, 4H), 7.16 - 7.02 (m, 8H), 4.32 (ddd, J = 11.7, 7.4, 5.7 Hz, 2H), 4.17 - 4.01 (m, 10H), 3.97 - 3.72 (m, 12H), 3.67 - 3.52 (m, 4H), 3.27 (d, J = 6.4 Hz, 2H), 2.94 - 2.65 (m, 4H), 2.48 (dd, J = 16.6, 8.7 Hz, 1H), 1.93 - 1.14 (m, 26H), 1.00 - 0.82 (m, 9H); N4: Add 800 ml of absolute ethanol and 0.1 mol of tetramisole compound into a reaction kettle, stir and mix evenly, heat up to 60 °C, under nitrogen protection, dropwise add 0.45 mol of 1-bromododecane, finish dropping in 30 min, reflux and react for 48 h, cool to room temperature, distill under reduced pressure at 60 °C for 2 h, wash with acetone twice (500 ml each time), dry in vacuum at 50 °C for 6 h to obtain a surfactant; the 1H NMR data thereof are as follows: 1 1H NMR (300 MHz, Chloroform- d ) δ 10.13 (tt, J = 1.7, 0.9 Hz, 4H), 7.88 (ddt, J = 4.2, 1.7, 0.9 Hz, 4H), 7.71 (ddt, J = 4.3, 1.7, 0.9 Hz, 4H), 4.91 (tt, J = 5.6, 0.9 Hz, 8H), 4.39 - 4.26 (m, 2H), 4.24 - 4.02 (m, 10H), 3.97 - 3.71 (m, 12H), 3.68 - 3.53 (m, 4H), 3.27 (d, J = 6.4 Hz, 2H), 2.93 - 2.67 (m, 4H), 2.48 (dd, J = 16.7, 8.7 Hz, 1H), 2.08 (tt, J = 7.8, 5.6 Hz, 8H), 1.94 - 1.16 (m, 98H), 1.01 - 0.81 (m, 21H).

[0022] Example 2 Preparation of spherical yttrium oxide: S1: Stir and mix 100 ml of an alcoholic solution of triethanolamine (the concentration of triethanolamine is 1 mol / L and the solvent is ethanol) and 500 ml of ammonia water (28 wt%) to obtain a mixed precipitant solution; S2: Using the reverse feeding method, slowly add 100 ml of 0.1 mol / L yttrium nitrate solution to 600 ml of the 60°C mixed precipitant solution through a peristaltic pump. Finish adding in 1.5 h, age for 2 h, filter, wash twice with deionized water (500 g each time), and vacuum dry at 60°C for 10 h to obtain a precursor precipitate; S3: Stir and mix 300 g of 1,2 - propanediol, 50 g of the precursor precipitate, and 5 g of a surfactant (prepared in Example 1), carry out a high-temperature and high-pressure reaction at 0.5 Mpa and 100°C for 24 h, filter, wash twice with deionized water (500 g each time), vacuum dry at 60°C for 10 h, and calcine at 700°C for 5 h to obtain spherical yttrium oxide.

[0023] Example 3 Preparation of spherical yttrium oxide: S1: Stir and mix 100 ml of an alcoholic solution of triethanolamine (the concentration of triethanolamine is 1.5 mol / L and the solvent is n-butanol) and 800 ml of ammonia water (25 wt%) to obtain a mixed precipitant solution; S2: Using the reverse feeding method, slowly add 150 ml of 0.15 mol / L yttrium nitrate solution to 900 ml of the 70°C mixed precipitant solution through a peristaltic pump. Finish adding in 1.5 h, age for 1.5 h, filter, wash twice with deionized water (500 g each time), and vacuum dry at 60°C for 10 h to obtain a precursor precipitate; S3: Stir and mix 450 g of 1,2 - propanediol, 50 g of the precursor precipitate, and 5 g of a surfactant (prepared in Example 1), carry out a high-temperature and high-pressure reaction at 5 Mpa and 130°C for 20 h, filter, wash twice with deionized water (500 g each time), vacuum dry at 60°C for 10 h, and calcine at 750°C for 4 h to obtain spherical yttrium oxide.

[0024] Example 4 Preparation of spherical yttrium oxide: S1: Stir and mix 100 ml of an alcoholic solution of triethanolamine (the concentration of triethanolamine is 2 mol / L and the solvent is n-hexanol) and 1 L of ammonia water (20 wt%) to obtain a mixed precipitant solution; S2: Using the reverse feeding method, slowly add 200 ml of 0.2 mol / L yttrium nitrate solution to 1100 ml of the 80°C mixed precipitant solution through a peristaltic pump. Finish adding in 1.5 h, age for 1 h, filter, wash twice with deionized water (500 g each time), and vacuum dry at 60°C for 10 h to obtain a precursor precipitate; S3: Stir 600 g of 1,2 - propanediol, 50 g of the precursor precipitate, and 5 g of the surfactant (prepared in Example 1) evenly, carry out a high - temperature and high - pressure reaction at 8.0 Mpa and 150 °C for 12 h, filter, wash twice with deionized water (500 g each time), dry in vacuum at 60 °C for 10 h, and calcine at 800 °C for 3 h to obtain spherical yttrium oxide.

[0025] Example 5: Preparation of spherical yttrium oxide: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 2, except that the addition amount of the surfactant (prepared in Example 1) in step S3 is replaced from 5 g to 8 g.

[0026] Example 6: Preparation of spherical yttrium oxide: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 2, except that the addition amount of the surfactant (prepared in Example 1) in step S3 is replaced from 5 g to 10 g.

[0027] Example 7: Preparation of spherical yttrium oxide: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 2, except that the addition amount of the surfactant (prepared in Example 1) in step S3 is replaced from 5 g to 15 g.

[0028] Comparative Example 1: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 5, except that the surfactant (prepared in Example 1) in step S3 is replaced with a surfactant prepared by the following method with the same weight: The preparation method of the surfactant is basically the same as that in Example 1. The difference is that 2,6 - nonadien - 1 - ol in step N1 is replaced with an equimolar amount of cis - 6 - nonen - 1 - ol.

[0029] Comparative Example 2: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 5, except that the surfactant (prepared in Example 1) in step S3 is replaced with a surfactant prepared by the following method with the same weight: The preparation method of the surfactant is basically the same as that in Example 1. The difference is that 1 - (2 - hydroxyethyl) imidazole in step N3 is replaced with an equimolar amount of 3 - dimethylamino - 1 - propanol.

[0030] Comparative Example 3: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 5, except that the surfactant (prepared in Example 1) in step S3 is replaced with a surfactant prepared by the following method with the same weight: N1: Under nitrogen protection, add 400 ml of anhydrous THF, 0.3 mol of potassium carbonate, and 0.2 mol of 2,6-nonadien-1-ol into the reaction kettle, stir for 30 min, cool down to 0 °C, and dropwise add 100 ml of a tetrahydrofuran solution containing 0.1 mol of 1,12-dichlorododecane. Finish dropping in 30 min, raise the temperature to room temperature and react for 5 h. Wash three times with saturated brine (200 ml each time), and conduct vacuum distillation at 30 °C for 2 h to obtain a double-bond compound; N2: Add 300 ml of DMF, 50 g of the double-bond compound, and 5 g of strong-acid cation exchange resin into the reaction kettle in sequence, stir and heat up to 60 °C, dropwise add a mixed solution of 30 g of formic acid and 45 g of 30 wt% H2O2. Finish dropping in 30 min, continue to react for 6 h, conduct vacuum distillation at 60 °C for 3 h, wash three times with deionized water (300 ml each time), and conduct vacuum drying at 50 °C for 10 h to obtain an epoxy compound; N3: Under nitrogen protection, add 600 ml of isopropanol, 0.1 mol of the epoxy compound, and 0.5 mol of 1-(2-hydroxyethyl)imidazole into the reaction kettle in sequence, stir and mix evenly, add 10 g of tetraethylammonium bromide, heat up to 70 °C and react for 4 h, cool down, conduct vacuum distillation at 50 °C for 2 h, wash three times with deionized water (300 ml each time), and conduct vacuum drying at 70 °C for 12 h to obtain a tetramidazole compound; N4: Add 800 ml of anhydrous ethanol and 0.1 mol of the tetramidazole compound into the reaction kettle, stir and mix evenly, heat up to 60 °C, and under nitrogen protection, dropwise add 0.45 mol of 1-bromododecane. Finish dropping in 30 min, reflux and react for 48 h, cool down to room temperature, conduct vacuum distillation at 60 °C for 2 h to obtain a white solid. Wash twice with acetone (500 ml each time), and conduct vacuum drying at 50 °C for 6 h to obtain a surfactant.

[0031] Comparative Example 4: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 5, except that the surfactant (prepared in Example 1) in step S3 is replaced with a surfactant prepared by the following method with the same weight: The preparation method of the surfactant is basically the same as that in Example 1, except that 1-bromododecane in step N4 is replaced with an equimolar amount of 1-bromohexane.

[0032] Comparative Example 5: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 5, except that the surfactant (prepared in Example 1) in step S3 is replaced with PEG2000 with the same weight.

[0033] Comparative Example 6: The raw material composition and preparation method of spherical yttrium oxide are basically the same as those in Example 5, except that the surfactant (prepared in Example 1) in step S3 is replaced with CTAB with the same weight.

[0034] The yttrium oxide prepared in Examples 2-7 of this application was subjected to morphological characterization; the yttrium oxide prepared in Examples 2-7 and Comparative Examples 1-6 of this application was tested for particle size distribution using a laser particle size analyzer (using sodium hexametaphosphate as a dispersant and then dispersing it in an ultrasonic oscillator for 5 minutes), and the test results are shown in Table 1.

[0035] Table 1 Particle Size Distribution of Spherical Yttrium Oxide

[0036] Note: The values of the particle size distribution in the above table are rounded.

[0037] It can be seen from Examples 2, 5, 6, and 7 in Table 1 that the spherical yttrium oxide particles prepared by the present invention have good dispersibility and no agglomeration phenomenon; the particle size is uniform and controllable, and the particle size distribution range is narrow. Spherical yttrium oxide with a size of several hundred nanometers can be prepared according to the addition amount of the surfactant.

[0038] The imidazole N, ester group (-COO-), and ether bond in the surfactant prepared in this application have relatively large polarity and have strong chemical adsorption or chemical bonding effects on nanoparticles. The imidazolium quaternary ammonium cation is adsorbed on the surface of nanoparticles through electrostatic interaction and interacts with the hydrophobic long-chain alkyl group to form micelles with an aggregation tendency, providing a confined space for the growth of nanomaterials. The surfactant prepared in this application can form a molecular film on the surface of nanoparticles to prevent the particles from contacting each other and improve the dispersion performance. In addition, the steric hindrance of the imidazole ring and the electrostatic repulsion of the quaternary ammonium salt can prevent the further growth of nanoparticles. The surfactant used in Comparative Example 1 has only two quaternary ammonium salts, and the adsorption and dispersion are uneven, resulting in larger particle sizes and a wider particle size distribution of yttrium oxide nanoparticles; the surfactant used in Comparative Example 4 has a shorter hydrophobic chain, and the dispersion of nanoparticles is poor, resulting in uncontrollable particle size growth.

[0039] It can be seen through Figure 2-7 that the yttrium oxide prepared in this application is spherical particles.

[0040] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; however, for those of ordinary skill in the art, without departing from the scope of the technical solution of the present invention, any equivalent changes such as slight modifications, evolutions made using the technical content disclosed above are all equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A preparation method of monodisperse spherical yttrium oxide with controllable particle size, characterized in that, It includes the following steps: S1: Stir and mix the alcohol solution of triethanolamine and ammonia water to obtain a mixed precipitant solution; S2: Slowly add the yttrium nitrate solution to the mixed precipitant solution at 60 - 80 °C. After adding, age, filter, and wash with deionized water to obtain a precursor precipitate; S3: Stir and mix 1,2 - propanediol, the precursor precipitate, and a surfactant, carry out a high - temperature and high - pressure reaction, filter, wash, dry, and calcine to obtain spherical yttrium oxide; The surfactant is prepared by the following method: N1: 2,6 - nonadien - 1 - ol reacts with octyl succinic anhydride to form an ester - based double - bond compound; N2: The ester - based double - bond compound reacts under the action of formic acid and 30wt% H2O2 to form an epoxide; N3: The epoxide reacts with 1 - (2 - hydroxyethyl)imidazole to form a tetramidazole compound; N4: The tetramidazole compound reacts with 1 - bromododecane to form a surfactant.

2. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step N1, the feeding molar ratio of 2,6 - nonadien - 1 - ol to octyl succinic anhydride is 2:

1.

3. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step N2, the feeding mass ratio of the ester - based double - bond compound, formic acid, and 30wt% H2O2 is 10:6:

9.

4. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step N3, the feeding molar ratio of the epoxide to 1 - (2 - hydroxyethyl)imidazole is 1:

5.

5. The preparation method of a monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step N4, the feeding molar ratio of the tetramidazole compound to 1 - bromododecane is 1:4.

5.

6. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step S1, the solvent in the alcohol solution of triethanolamine is one of ethanol, n - butanol, and n - hexanol.

7. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step S1, the concentration of the alcohol solution of triethanolamine is 1 - 2 mol / L, and the feeding volume ratio of ammonia water to the alcohol solution of triethanolamine is (5 - 10):

1.

8. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step S2, the concentration of the yttrium nitrate solution is 0.1 - 0.2 mol / L.

9. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step S2, the feeding molar ratio of triethanolamine in the mixed precipitant solution to yttrium nitrate in the yttrium nitrate solution is 10:(1 - 2).

10. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step S3, the feeding mass ratio of the precursor precipitate, surfactant, and 1,2 - propanediol is 50:(5 - 15):(300 - 600).

11. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step S3, the high - temperature and high - pressure reaction temperature is 100 - 150 °C, the time is 12 - 24 h, and the pressure is 0.5 - 8.0 Mpa.

12. The preparation method of monodisperse spherical yttrium oxide with controllable particle size according to claim 1, characterized in that, In step S3, the calcination temperature is 700 - 800 °C, and the time is 3 - 5 h.

Images