Spherical nano rare earth oxide and preparation method thereof

Abstract

The invention provides a spherical nano rare earth oxide and a preparation method thereof. The preparation method comprises the following steps: mixing a first solvent and a second solvent to obtain a mixed solvent; dispersing a rare earth metal salt, a precipitating agent and a dispersing agent in the mixed solvent to obtain a reaction solution; carrying out heating reaction on the reaction liquid; carrying out solid-liquid separation to obtain a spherical nano rare earth oxide precursor; and calcining the spherical nano rare earth oxide precursor to obtain the spherical nano rare earth oxide. According to the preparation method, the solvent is selected, the rare earth metal salt, the precipitant and the dispersing agent are matched in a specific solvent environment, and the spherical nano rare earth oxide with high sphericity degree and uniform and controllable particle size is prepared through a heating reaction. The preparation method provided by the invention is simple, easy to implement and suitable for large-scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nanomaterials, in particular to the preparation of rare earth oxides, and more particularly to a spherical nanometer rare earth oxide and a preparation method thereof. BACKGROUND

[0002] Rare earth oxides are widely used in traditional industries and high-tech fields such as metallurgy, ceramics, petroleum, chemical industry, textiles, glass, permanent magnetism, etc. due to their unique physical and chemical properties such as magnetism, electricity, heat, light, etc. For example, they are used in permanent magnet materials, luminescent materials, catalytic materials, ceramic materials, etc. At the same time, by doping rare earth oxides into various functional materials, the physical and chemical properties of the materials can be significantly improved, and their photoelectric properties can be effectively enhanced. These excellent performance characteristics make rare earth oxides widely used in high-tech materials.

[0003] However, at present, rare earth oxides are mainly prepared by precipitation method. Alkaline solutions such as carbonates, bicarbonates, ammonia, etc. or oxalic acid solution are used as precipitants. Under specific conditions, rare earth ions are precipitated into corresponding precursors. After drying and calcining the precursors, rare earth oxides are obtained. However, the rare earth oxides prepared by the precipitation method have large particle size, serious agglomeration and uneven morphology, which cannot meet the needs of high-end materials for particle size, morphology and uniformity of rare earth oxides.

[0004] CN102351235A discloses a rare earth complex, a rare earth oxide and a preparation method thereof. Single or multiple rare earth nitrate, N,N-dimethylformamide and water are used as raw materials to prepare a rare earth-N,N-dimethylformamide complex with one-dimensional or polyhedral morphology by solvothermal reaction. The morphology of the rare earth complex is controlled by adjusting the reaction time. The rare earth oxide with similar morphology to the precursor can be prepared by heating decomposition reaction of the complex as the precursor. The preparation method has simple preparation process, does not require complex and expensive equipment, can easily obtain single or doped rare earth complex and corresponding oxide, and the raw materials are cheap and easy to obtain, so that industrial production can be realized.

[0005] CN114180613A discloses a method for preparing rare earth oxides by ammonia and carbon recycling, comprising the following steps: (1) calcining raw materials including first rare earth carbonate and first rare earth oxide at 500-1000℃ for 20-120min by microwave heating to obtain second rare earth oxide and carbon dioxide; (2) reacting carbon dioxide with first ammonia water to obtain a precipitant; (3) reacting the precipitant with rare earth chloride to obtain second rare earth carbonate and ammonium chloride wastewater. The method has short calcination time, and high rare earth recovery rate and ammonia and carbon resource utilization rate.

[0006] CN101412529A discloses a preparation method of rare earth oxide or composite rare earth oxide nanopowder by a molten salt synthesis method. One or more kinds of soluble rare earth salts are used as the rare earth source, and are dissolved in water to form a uniform solution under stirring; an alkaline solution such as ammonia water or sodium hydroxide is used as a pH regulator to form a rare earth hydroxide precipitate or co-precipitate; one or more kinds of salts such as sodium sulfate, potassium sulfate or sodium chloride are used to form a molten salt system; the rare earth hydroxide precipitate or co-precipitate is mixed with the water solution of the molten salt, is stirred uniformly, and is gradually heated to evaporate and dry the water, so as to form a rare earth hydroxide precipitate or co-precipitate-molten salt precursor; after high-temperature molten salt synthesis under normal pressure, the nanopowder is prepared by full washing and drying, and has a particle size of less than 100 nm and good dispersibility.

[0007] Therefore, it is of great significance to provide a preparation process of spherical nanometer rare earth oxide with high sphericity and controllable particle size. SUMMARY

[0008] In view of the deficiencies in the prior art, the purpose of the present application is to provide a spherical nanometer rare earth oxide and a preparation method thereof. The spherical nanometer rare earth oxide with high sphericity and controllable particle size is prepared by selecting solvents, using rare earth metal salts, precipitants and dispersants in a specific solvent environment, and performing a heating reaction. The preparation method provided by the present application is simple and easy to implement, and is suitable for large-scale production.

[0009] To achieve the purpose of the present application, the following technical solutions are adopted:

[0010] In a first aspect, the present application provides a preparation method of spherical nanometer rare earth oxide, which comprises:

[0011] The first solvent and the second solvent are mixed to obtain a mixed solvent; rare earth metal salts, precipitants and dispersants are dispersed in the mixed solvent to obtain a reaction solution; the reaction solution is subjected to a heating reaction; solid-liquid separation is performed to obtain a spherical nanometer rare earth oxide precursor; and the spherical nanometer rare earth oxide precursor is calcined to obtain the spherical nanometer rare earth oxide; the first solvent comprises any one of water, methanol, ethanol, propanol, butanol or pentanol; and the second solvent comprises any one of pentaerythritol, dipropylene glycol, neopentyl glycol, butanediol, propylene glycol, ethylene glycol, diethylene glycol or glycerol.

[0012] The spherical nanometer rare earth oxide with high sphericity and controllable particle size is prepared by selecting solvents, using different kinds of first solvents and second solvents in mixture, using rare earth metal salts, precipitants and dispersants in a specific solvent environment, and performing a heating reaction. The preparation method provided by the present application is simple and easy to implement, and is suitable for large-scale production.

[0013] Preferably, the volume ratio of the first solvent to the second solvent is (0.1-1):1.

[0014] Preferably, the rare earth metal salt comprises any one or a combination of at least two of chlorides, nitrates, sulfates or acetates of rare earth elements.

[0015] Preferably, the precipitant comprises any one or a combination of at least two of oxalic acid, urea, ammonium carbonate or ammonium bicarbonate.

[0016] Preferably, the dispersant comprises any one or a combination of at least two of polyethylene glycol, polyvinylpyrrolidone, hydroxypropyl cellulose or hydroxypropyl methyl cellulose.

[0017] Preferably, the rare earth element comprises any one or a combination of at least two of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium or yttrium.

[0018] Preferably, the temperature of the heating reaction is 60-150°C, preferably 80-120°C.

[0019] Preferably, the time of the heating reaction is 1-24h, preferably 1-12h.

[0020] Preferably, the temperature of the calcination is 300-1000°C, preferably 500-800°C.

[0021] Preferably, the time of the calcination is 1-48h, preferably 1-24h.

[0022] Preferably, the concentration of the rare earth salt in the reaction solution is 0.05-0.5mol / L, preferably 0.1-0.3mol / L.

[0023] Preferably, the molar ratio of the precipitant to the rare earth metal salt in the reaction solution is (2-100):1, preferably (5-50):1.

[0024] Preferably, the concentration of the dispersant in the reaction solution is 1-100g / L, preferably 5-50g / L.

[0025] Preferably, the dispersing mode comprises stirring.

[0026] Preferably, the time of the dispersing is 30-120min.

[0027] Preferably, the solid-liquid separation mode comprises centrifugation.

[0028] Preferably, the centrifugal rotation speed is 5000rpm-15000rpm.

[0029] Preferably, the preparation method further comprises washing and drying the spherical nanometer rare earth oxide.

[0030] Preferably, the washing uses a washing agent comprising any one or a combination of at least two of water, ethanol or acetone.

[0031] Preferably, the drying temperature is 60℃-120℃.

[0032] Preferably, the drying time is 1h-24h.

[0033] In the second aspect, the application provides a spherical nanometer rare earth oxide, which is prepared by the preparation method of the first aspect; the average particle size of the spherical nanometer rare earth oxide is 30nm-200nm.

[0034] Compared with the prior art, the application has the following beneficial effects:

[0035] The application selects a solvent, and in a specific solvent environment, a rare earth metal salt, a precipitating agent and a dispersing agent are combined to prepare a spherical nanometer rare earth oxide with high sphericity, uniform and controllable particle size by heating reaction. The preparation method provided by the application is simple and easy to implement, and is suitable for large-scale production. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is an XRD pattern of the spherical nanometer ytterbium oxide prepared in Example 1.

[0037] Figure 2 is an SEM pattern of the spherical nanometer ytterbium oxide precursor prepared in Example 1.

[0038] Figure 3 is an SEM pattern of the spherical nanometer ytterbium oxide prepared in Example 1.

[0039] Figure 4 is an SEM pattern of the spherical nanometer ytterbium oxide prepared in Example 1.

[0040] Figure 5 is an SEM pattern of the spherical nanometer ytterbium oxide prepared in Example 1.

[0041] Figure 6 is an SEM pattern of the spherical nanometer ytterbium oxide prepared in Example 1.

[0042] Figure 7 is an SEM pattern of the spherical nanometer ytterbium oxide prepared in Example 1.

[0043] Figure 8 is a SEM image of spherical nanometer gadolinium oxide prepared in Example 7.

[0044] Figure 9 is a SEM image of spherical nanometer gadolinium oxide prepared in Example 7.

[0045] Figure 10 is a SEM image of spherical nanometer gadolinium oxide prepared in Example 7.

[0046] Figure 11 is a SEM image of spherical nanometer gadolinium oxide prepared in Example 7.

[0047] Figure 12 is a SEM image of spherical nanometer gadolinium oxide prepared in Example 7.

[0048] Figure 13 is a SEM image of spherical nanometer gadolinium oxide prepared in Example 7. DETAILED DESCRIPTION

[0049] The technical solutions of the present application will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only used to help understand the present application, and should not be regarded as specific limitations to the present application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application; the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion.

[0051] In the description of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0052] In one specific embodiment, the present application provides a preparation method of spherical nanometer rare earth oxide, which comprises:

[0053] mixing the first solvent and the second solvent to obtain a mixed solvent; dispersing a rare earth metal salt, a precipitant and a dispersant in the mixed solvent to obtain a reaction solution; performing a heating reaction on the reaction solution; performing a solid-liquid separation to obtain a spherical nanometer rare earth oxide precursor; and calcining the spherical nanometer rare earth oxide precursor to obtain the spherical nanometer rare earth oxide; the first solvent comprises any one of water, methanol, ethanol, propanol, butanol or pentanol; and the second solvent comprises any one of pentaerythritol, dipropylene glycol, neopentyl glycol, butanediol, propylene glycol, ethylene glycol, diethylene glycol or glycerol.

[0054] The present application uses different kinds of first solvents and second solvents in cooperation, which is conducive to preparing the nanometer rare earth oxide with uniform particle size and monodispersion. In a specific solvent environment, the rare earth metal salt, the precipitant and the dispersant are combined to prepare the spherical nanometer rare earth oxide with high sphericity, uniform and controllable particle size through a heating reaction. The preparation method provided by the present application is simple and easy to implement, and is suitable for large-scale production.

[0055] In the present application, the volume ratio of the first solvent to the second solvent affects the particle size uniformity and dispersity of the product prepared.

[0056] In some embodiments, the volume ratio of the first solvent to the second solvent is (0.1-1):1, for example, it can be 0.1:1, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1, 0.9:1 or 1:1, including but not limited to the listed values, and other values not listed in the value range are also applicable.

[0057] In some embodiments, the rare earth metal salt comprises any one or a combination of at least two of chlorides, nitrates, sulfates or acetates of rare earth elements, and a typical but non-limiting combination includes a combination of chlorides and nitrates, or a combination of sulfates and acetates.

[0058] In some embodiments, the precipitant comprises any one or a combination of at least two of oxalic acid, urea, ammonium carbonate or ammonium bicarbonate, and a typical but non-limiting combination includes a combination of oxalic acid and urea, a combination of ammonium carbonate and ammonium bicarbonate, a combination of urea and ammonium carbonate, or a combination of ammonium bicarbonate and oxalic acid.

[0059] In some embodiments, the dispersant comprises any one or a combination of at least two of polyethylene glycol, polyvinylpyrrolidone, hydroxypropyl cellulose or hydroxypropyl methyl cellulose, and a typical but non-limiting combination includes a combination of polyethylene glycol and polyvinylpyrrolidone, a combination of hydroxypropyl cellulose and hydroxypropyl methyl cellulose, a combination of polyvinylpyrrolidone and hydroxypropyl cellulose, or a combination of hydroxypropyl methyl cellulose and polyethylene glycol.

[0060] In some embodiments, the rare earth element comprises any one of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium or yttrium, or a combination of at least two of them, typical but non-limiting combinations include a combination of lanthanum and cerium, a combination of praseodymium and neodymium, a combination of promethium and samarium, a combination of europium and gadolinium, a combination of terbium and dysprosium, a combination of holmium and erbium, a combination of thulium and ytterbium, a combination of lutetium and scandium, or a combination of yttrium and cerium.

[0061] In some embodiments, the heating reaction is performed at a temperature of 60-150°C, for example, it can be 60°C, 80°C, 100°C, 110°C, 120°C, 130°C, 140°C or 150°C, including but not limited to the listed values, other values not listed within the range of values are also applicable.

[0062] In some embodiments, the heating reaction is performed for a time period of 1-24h, for example, it can be 1h, 3h, 5h, 7h, 9h, 12h, 14h, 16h, 18h, 20h, 22h or 24h, including but not limited to the listed values, other values not listed within the range of values are also applicable, preferably 1-12h.

[0063] In some embodiments, the calcination is performed at a temperature of 300-1000°C, for example, it can be 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C or 1000°C, including but not limited to the listed values, other values not listed within the range of values are also applicable, preferably 500-800°C.

[0064] In some embodiments, the calcination is performed for a time period of 1-48h, for example, it can be 1h, 5h, 10h, 15h, 20h, 24h, 30h, 35h, 40h, 45h or 48h, including but not limited to the listed values, other values not listed within the range of values are also applicable, preferably 1-24h.

[0065] In some embodiments, the concentration of the rare earth salt in the reaction solution is 0.05-0.5mol / L, for example, it can be 0.05mol / L, 0.1mol / L, 0.2mol / L, 0.3mol / L, 0.4mol / L or 0.5mol / L, including but not limited to the listed values, other values not listed within the range of values are also applicable, preferably 0.1-0.3mol / L.

[0066] In some embodiments, the molar ratio of the precipitant to the rare earth metal salt in the reaction solution is (2-100): 1, for example, it can be 2:1, 10:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1 or 100:1, including but not limited to the listed values, other values not listed in the range of values are also applicable.

[0067] In some embodiments, the concentration of the dispersant in the reaction solution is 1 g / L-100 g / L, for example, it can be 1 g / L, 10 g / L, 20 g / L, 30 g / L, 40 g / L, 50 g / L, 60 g / L, 70 g / L, 80 g / L, 90 g / L or 100 g / L, including but not limited to the listed values, other values not listed in the range of values are also applicable.

[0068] In some embodiments, the dispersion includes stirring.

[0069] In some embodiments, the dispersion time is 30 min-120 min, for example, it can be 30 min, 50 min, 70 min, 90 min, 100 min or 120 min, including but not limited to the listed values, other values not listed in the range of values are also applicable.

[0070] In some embodiments, the solid-liquid separation includes centrifugation.

[0071] In some embodiments, the centrifugation speed is 5000 rpm-15000 rpm, for example, it can be 5000 rpm, 7500 rpm, 10000 rpm, 12500 rpm, 15000 rpm, including but not limited to the listed values, other values not listed in the range of values are also applicable.

[0072] In some embodiments, the preparation method further includes washing and drying the spherical nanometer rare earth oxide.

[0073] In some embodiments, the washing uses a washing agent including any one or a combination of at least two of water, ethanol or acetone.

[0074] In some embodiments, the drying temperature is 60°C-120°C, for example, it can be 60°C, 80°C, 100°C or 120°C, including but not limited to the listed values, other values not listed in the range of values are also applicable.

[0075] In some embodiments, the drying time is 1 hour to 24 hours, for example, it can be 1 hour, 3 hours, 5 hours, 7 hours, 9 hours, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours or 24 hours, including but not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0076] In another specific embodiment, the present invention provides a spherical rare earth nanoparticle oxide, which is prepared by the preparation method described in one of the preceding specific embodiments; the average particle size of the spherical rare earth nanoparticle oxide is 30nm to 200nm, for example, it can be 30nm, 50nm, 80nm, 100nm, 120nm, 140nm, 160nm, 180nm or 200nm, including but not limited to the listed values, and other unlisted values ​​within the range are also applicable.

[0077] Example 1

[0078] This embodiment provides a method for preparing spherical ytterbium nanoparticles, the method comprising:

[0079] A mixed solvent was prepared by mixing pentanol and ethanol at a volume ratio of 1:0.05. Ytterbium chloride, urea, and polyethylene glycol were added, and the mixture was stirred for 30 minutes to obtain a reaction solution with a ytterbium chloride concentration of 0.1 mol / L, a polyethylene glycol concentration of 5 g / L, and a urea to ytterbium chloride molar ratio of 20:1. The reaction solution was reacted in an oil bath at 100°C for 24 hours and then naturally cooled to room temperature. The solid and liquid components were separated by centrifugation at 12000 rpm, and the mixture was washed three times with water and dried in an oven at 60°C for 12 hours to obtain spherical nano-ytterbium oxide precursors. After calcination at 600°C for 12 hours, spherical nano-ytterbium oxide with a particle size of 80 nm was obtained.

[0080] according to Figure 1 The XRD diffraction pattern shown demonstrates the successful preparation of ytterbium oxide material in this embodiment. Figure 2 As shown in the SEM image of the spherical ytterbium oxide nanoparticle precursor, the spherical ytterbium oxide nanoparticle precursor prepared in this embodiment has a monodisperse, uniform spherical morphology with an average particle size of 100 nm. Figure 3 As shown in the SEM image of the spherical ytterbium oxide nanoparticles obtained after calcination, the spherical ytterbium oxide nanoparticles maintain a monodisperse and uniform spherical morphology after calcination, and the average particle size is reduced to 80 nm.

[0081] Example 2

[0082] This embodiment provides a method for preparing spherical yttrium oxide nanoparticles, the method comprising:

[0083] A mixed solvent was prepared by mixing isopropanol and water at a volume ratio of 1:0.1. Yttrium nitrate, ammonium carbonate, and hydroxypropyl cellulose were added, and the mixture was stirred for 60 minutes to obtain a reaction solution with a yttrium nitrate concentration of 0.2 mol / L, a hydroxypropyl cellulose concentration of 1 g / L, and a urea to yttrium nitrate molar ratio of 2:1. The reaction solution was reacted in an oil bath at 70°C for 12 hours and then naturally cooled to room temperature. The solid and liquid components were separated by centrifugation at 5000 rpm, and the mixture was washed three times with water and dried in an oven at 80°C for 24 hours to obtain spherical yttrium oxide nanoparticles precursor. After calcination at 800°C for 4 hours, spherical yttrium oxide nanoparticles with a particle size of 100 nm were obtained.

[0084] like Figure 4 As shown in the SEM image of the spherical yttrium oxide nanoparticles obtained after calcination, the spherical yttrium oxide nanoparticles maintain a monodisperse and uniform spherical morphology after calcination, and the average particle size is reduced to 120 nm.

[0085] Example 3

[0086] This embodiment provides a method for preparing spherical yttrium oxide nanoparticles, the method comprising:

[0087] A mixed solvent was prepared by mixing diethylene glycol and methanol at a volume ratio of 1:0.5. Yttrium sulfate, ammonium bicarbonate, and hydroxypropyl cellulose were added, and the mixture was stirred for 60 minutes to obtain a reaction solution with a yttrium sulfate concentration of 0.3 mol / L, a hydroxypropyl cellulose concentration of 6 g / L, and a urea to yttrium sulfate molar ratio of 10:1. The reaction solution was reacted in an oil bath at 110°C for 6 hours and then naturally cooled to room temperature. The solid and liquid components were separated by centrifugation at 8000 rpm, and the mixture was washed three times with water and dried in an oven at 100°C for 10 hours to obtain spherical yttrium oxide nanoparticles precursor. After calcination at 700°C for 8 hours, spherical yttrium oxide nanoparticles with a particle size of 80 nm were obtained.

[0088] like Figure 5 As shown in the SEM image of the spherical yttrium oxide nanoparticles obtained after calcination, the spherical yttrium oxide nanoparticles maintain a monodisperse and uniform spherical morphology after calcination, and the average particle size is reduced to 80 nm.

[0089] Example 4

[0090] This embodiment provides a method for preparing spherical yttrium oxide nanoparticles, the method comprising:

[0091] The glycerol and ethanol are mixed in a volume ratio of 1:0.8 to obtain a mixed solvent, and yttrium acetate, oxalic acid and polyvinylpyrrolidone are added and stirred for 120 minutes to obtain a reaction solution with a yttrium acetate concentration of 0.5 mol / L, a polyvinylpyrrolidone concentration of 50 g / L and a molar ratio of urea to yttrium acetate of 50:1; the reaction solution is reacted in an oil bath at 130°C for 2 hours, and then naturally cooled to room temperature; the centrifugal speed is set to 10000 rpm, and solid-liquid separation is performed, and then washed with water for 3 times, and dried in an oven at 120°C for 24 hours to obtain spherical nanometer yttrium oxide precursor; after calcination at 400°C for 1 hour, spherical nanometer yttrium oxide with a particle size of 50 nm is prepared.

[0092] As shown in the SEM image of the spherical nanometer yttrium oxide obtained after calcination, the spherical nanometer yttrium oxide maintains a uniform spherical morphology after calcination, and the average particle size is reduced to 50 nm. Figure 6

[0093] Example 5

[0094] The embodiment provides a preparation method of spherical nanometer holmium oxide, and the preparation method comprises the following steps:

[0095] The ethylene glycol and isopropyl alcohol are mixed in a volume ratio of 1:1 to obtain a mixed solvent, and holmium chloride, urea and polyvinylpyrrolidone are added and stirred for 40 minutes to obtain a reaction solution with a holmium chloride concentration of 0.05 mol / L, a polyvinylpyrrolidone concentration of 10 g / L and a molar ratio of urea to holmium chloride of 30:1; the reaction solution is reacted in an oil bath at 150°C for 1 hour, and then naturally cooled to room temperature; the centrifugal speed is set to 10000 rpm, and solid-liquid separation is performed, and then washed with water for 3 times, and dried in an oven at 100°C for 6 hours to obtain spherical nanometer holmium oxide precursor; after calcination at 1000°C for 2 hours, spherical nanometer holmium oxide with a particle size of 80 nm is prepared.

[0096] As shown in the SEM image of the spherical nanometer holmium oxide obtained after calcination, the spherical nanometer holmium oxide maintains a uniform spherical morphology after calcination, and the average particle size is reduced to 80 nm. Figure 7

[0097] Example 6

[0098] The embodiment provides a preparation method of spherical nanometer terbium oxide, and the preparation method comprises the following steps:

[0099] ​​The ethylene glycol and isopropyl alcohol are mixed in a volume ratio of 1:0.5 to obtain a mixed solvent, and terbium nitrate, ammonium carbonate and polyethylene glycol are added and stirred for 60 minutes to obtain a reaction solution with a terbium nitrate concentration of 0.3 mol / L, a polyethylene glycol concentration of 20 g / L and a molar ratio of urea to terbium nitrate of 100:1; the reaction solution is reacted in an oil bath at 60℃ for 24 hours, and then naturally cooled to room temperature; a centrifugal speed of 10000 rpm is set for solid-liquid separation, and the obtained product is washed with water for 3 times and dried in an oven at 60℃ for 24 hours to obtain a spherical nano terbium oxide precursor; after calcination at 900℃ for 4 hours, a spherical nano terbium oxide with a particle size of 90 nm is prepared.

[0100] As shown in the SEM image of the spherical nano terbium oxide obtained after calcination, the spherical nano terbium oxide maintains a uniform spherical morphology after calcination, and the average particle size is reduced to 90 nm. Figure 8

[0101] Example 7

[0102] The embodiment provides a preparation method of spherical nano gadolinium oxide, and the preparation method comprises the following steps:

[0103] The ethylene glycol and isopropyl alcohol are mixed in a volume ratio of 1:0.5 to obtain a mixed solvent, and gadolinium sulfate, urea and hydroxypropyl cellulose are added and stirred for 30 minutes to obtain a reaction solution with a gadolinium sulfate concentration of 0.2 mol / L, a hydroxypropyl cellulose concentration of 30 g / L and a molar ratio of urea to gadolinium sulfate of 30:1; the reaction solution is reacted in an oil bath at 100℃ for 6 hours, and then naturally cooled to room temperature; a centrifugal speed of 10000 rpm is set for solid-liquid separation, and the obtained product is washed with water for 3 times and dried in an oven at 80℃ for 12 hours to obtain a spherical nano gadolinium oxide precursor; after calcination at 500℃ for 6 hours, a spherical nano gadolinium oxide with a particle size of 100 nm is prepared.

[0104] As shown in the SEM image of the spherical nano gadolinium oxide obtained after calcination, the spherical nano gadolinium oxide maintains a uniform spherical morphology after calcination, and the average particle size is reduced to 90 nm. Figure 9

[0105] Example 8

[0106] The embodiment provides a preparation method of spherical nano lutetium oxide, and the preparation method comprises the following steps:

[0107] ​​A mixed solvent was prepared by mixing pentanol and isopropanol at a volume ratio of 1:0.1. Lutene nitrate, ammonium bicarbonate, and hydroxypropyl methylcellulose were added, and the mixture was stirred for 60 minutes to obtain a reaction solution with a lutetene nitrate concentration of 0.1 mol / L, a hydroxypropyl methylcellulose concentration of 10 g / L, and a urea to lutetene nitrate molar ratio of 5:1. The reaction solution was reacted in an oil bath at 80°C for 12 hours and then naturally cooled to room temperature. The solid and liquid components were separated by centrifugation at 12000 rpm, and the mixture was washed three times with water and dried in a 70°C oven for 10 hours to obtain spherical lutetene oxide nano-precursor. After calcination at 300°C for 12 hours, spherical lutetene oxide nano-precursor with a particle size of 50 nm was obtained.

[0108] like Figure 10 As shown in the SEM image of the spherical lutetium oxide nanoparticles obtained after calcination, the spherical lutetium oxide nanoparticles maintain a monodisperse and uniform spherical morphology after calcination, and the average particle size is reduced to 50 nm.

[0109] Example 9

[0110] This embodiment provides a method for preparing spherical nano-ytterbium oxide. The preparation method is the same as in Example 1, except that the volume ratio of pentanol to ethanol is 1:0.03.

[0111] like Figure 11 The SEM image of the spherical ytterbium nanoparticles obtained after calcination shows that the spherical ytterbium nanoparticles have a spherical morphology, but some aggregation exists.

[0112] Example 10

[0113] This embodiment provides a method for preparing spherical nano-ytterbium oxide. The preparation method is the same as in Example 1, except that the volume ratio of pentanol to ethanol is 1:1.2.

[0114] like Figure 12 The SEM image of the spherical ytterbium nanoparticles obtained after calcination shows that the spherical ytterbium nanoparticles have a spherical morphology, but the size uniformity is poor.

[0115] Comparative Example 1

[0116] This comparative example provides a method for preparing nano-ytterbium oxide. The method is identical to that of Example 1, except that it uses only pentanol as a solvent. The reaction rate is extremely low, and almost no product is produced.

[0117] Comparative Example 2

[0118] This comparative example provides a method for preparing nano-ytterbium oxide, which is the same as in Example 1 except that it uses only ethanol as a solvent.

[0119] like Figure 13It can be seen from the SEM image of the nano ytterbium oxide obtained after calcination that the nano ytterbium oxide after calcination is rod-like structure, and the uniformity of size is poor, and the particles are seriously aggregated.

[0120] The applicant declares that the above description is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and it should be understood by those skilled in the art that any changes or replacements within the technical scope disclosed by the present application can be easily thought out by those skilled in the art, and all fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for preparing spherical nanosized rare earth oxide, characterized in that, The preparation method comprises: mixing a first solvent and a second solvent to obtain a mixed solvent; dispersing a rare earth metal salt, a precipitant and a dispersant in the mixed solvent to obtain a reaction solution; performing a heating reaction on the reaction solution; performing solid-liquid separation to obtain a spherical nanometer rare earth oxide precursor; and calcining the spherical nanometer rare earth oxide precursor to obtain the spherical nanometer rare earth oxide; the first solvent comprises any one of water, methanol, ethanol, propanol, butanol or pentanol; the second solvent comprises any one of pentaerythritol, dipropylene glycol, neopentyl glycol, butanediol, propylene glycol, ethylene glycol, diethylene glycol or glycerol.

2. The production method according to claim 1, wherein The volume ratio of the first solvent to the second solvent is (0.1-1):

1.

3. The production method according to claim 1, wherein The rare earth metal salt comprises any one or a combination of at least two of chlorides, nitrates, sulfates or acetates of rare earth elements; and / or, the precipitant comprises any one or a combination of at least two of oxalic acid, urea, ammonium carbonate or ammonium bicarbonate; and / or, the dispersant comprises any one or a combination of at least two of polyethylene glycol, polyvinylpyrrolidone, hydroxypropyl cellulose or hydroxypropyl methyl cellulose.

4. The production method according to claim 3, wherein The rare earth element comprises any one or a combination of at least two of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, scandium or yttrium.

5. The production method according to claim 1, wherein The heating reaction is performed at a temperature of 60-150°C; and / or, the heating reaction is performed for a time of 1-24h; and / or, the calcination is performed at a temperature of 300-1000°C; and / or, the calcination is performed for a time of 1-48h.

6. The production method according to claim 1, wherein The concentration of the rare earth salt in the reaction solution is 0.05-0.5mol / L; and / or, the molar ratio of the precipitant to the rare earth metal salt in the reaction solution is (2-100):1; and / or, the concentration of the dispersant in the reaction solution is 1-100g / L.

7. The production method according to claim 1, wherein The dispersion is performed by stirring; and / or, the dispersion is performed for a time of 30-120min.

8. The production method according to claim 1, wherein The solid-liquid separation is performed by centrifugation at a speed of 5000-15000rpm.

9. The production method according to claim 1, wherein The preparation method further comprises washing and drying the spherical nanometer rare earth oxide.

10. A spherical nanorare earth oxide, characterized by, The spherical nanometer rare earth oxide is prepared by the preparation method of any one of claims 1-9; The average particle size of the spherical nanometer rare earth oxide is 30-200nm.

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