Carbide ceramic nano hollow sphere and preparation method thereof

Abstract

The invention discloses a carbide ceramic nano hollow sphere and a preparation method thereof, and belongs to the technical field of carbide ceramic nano hollow spheres. The preparation method disclosed by the invention comprises the following steps: mixing a polystyrene dispersion liquid with water and carbohydrates to obtain a polystyrene microsphere and carbohydrate mixed solution; carrying out hydrothermal reaction on the polystyrene microspheres and the saccharide mixed solution to obtain a reaction product; carrying out post-treatment on the reaction product to obtain microsphere powder; mixing the microsphere powder with a transition metal salt solution to obtain a mixed solution; stirring the mixed solution, standing, and separating to obtain solid particles; and carrying out heat treatment on the solid particles to obtain the carbide ceramic hollow nanospheres. According to the method, the diameter of the cavity of the sphere can be controlled by using templates with different particle sizes, so that different environment and performance requirements are met, and the technical problems that the size of the cavity is difficult to control and a catalyst and other foreign impurities need to be introduced in an existing preparation method are solved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of carbide ceramic nanometer hollow spheres, and particularly relates to a carbide ceramic nanometer hollow sphere and a preparation method thereof. BACKGROUND

[0002] The rapid development of high-tech fields such as aerospace and energy development has increasingly stringent requirements for the performance of materials in extreme high-temperature environments. Ultra-high-temperature carbide ceramic materials have great application potential in the field of thermal protection due to their high melting point, high hardness, good high-temperature chemical stability and other excellent characteristics. However, although traditional carbide ultra-high-temperature ceramics have excellent temperature resistance, they have deficiencies in thermal insulation performance. This is because the solid structure of ceramic particles allows heat to be rapidly conducted within the material, making it difficult to meet the extremely high requirements for thermal insulation performance in thermal protection environments. Carbide ultra-high-temperature ceramic hollow spheres provide an innovative solution to this problem. The unique feature of the hollow sphere structure is that the air or other filling gas in the cavity has a very low thermal conductivity, which can significantly hinder the transfer of heat and effectively reduce the thermal conductivity of the material, thereby greatly improving the thermal insulation performance of the material.

[0003] In the current existing preparation methods of carbide ceramic nanohollow spheres, document one "Feng Zhang, Xu Yang, Peng Wang, et al. General method for highly controlled preparation of ceramic hollow spheres from core-shell structures [J]. International Journal of Applied Ceramic Technology, 2020, 17(5): 2220-2227." uses CVD method to prepare SiC nanohollow spheres. This method can provide reference and guidance for the preparation of carbide ultrahigh-temperature ceramic nanohollow spheres by CVD method, but CVD method has high requirements for equipment and high preparation cost. Document two "Cun Li, Xiaogang Yang, Baojun Yang, et al. Synthesis of ZrC hollow nanospheres at low temperature [J]. European Journal of Inorganic Chemistry, 2003, 2003(19): 3534-3537." puts ZrCl4, C6Cl6 and excess Na into an autoclave and reacts at 600 ℃ for 20 hours to generate ZrC nanohollow spheres. This method uses the liquid droplets formed by sodium metal in the reaction process as a template to prepare ZrC nanohollow spheres. Since the size of the liquid droplets of sodium metal in the reaction process is difficult to adjust, the size of the hollow cavity of the nanohollow spheres is also difficult to control, and the residual sodium metal will affect the purity of the ZrC nanohollow spheres, which may affect their performance. Document three "Ningkai Yuan, Yao Yan, Yuhao Zhou, et al. Molten salts assisted one-pot synthesis of hollow transition metal carbides [J]. 2024." prepares NbC, VC, ZrC and TiC nanohollow spheres by molten salt method. Although this method can realize the preparation of carbide ceramic nanohollow spheres, in the reaction process, the molten salt system is easy to introduce impurity elements, which inevitably mix into the product, thereby reducing the purity of the carbide ceramic nanohollow spheres and adversely affecting their high-temperature performance and other related properties. Therefore, how to develop new technologies to realize the preparation of carbide ultrahigh-temperature ceramic nanohollow spheres with controllable hollow size without introducing catalysts such as molten salt to affect the purity of the materials is a great challenge at present. SUMMARY

[0004] The present application aims to provide a carbide ceramic nanometer hollow sphere and a preparation method thereof, so as to solve the technical problems that the existing preparation method is difficult to control the size of the cavity and needs to introduce catalyst and other foreign impurities.

[0005] In order to achieve the above-mentioned purpose, the present application adopts the following technical solutions: The present application discloses a preparation method of a carbide ceramic nanometer hollow sphere, comprising the following steps: Mixing a polystyrene dispersion liquid with water and a saccharide substance to obtain a polystyrene microsphere saccharide mixed solution; Carrying out a hydrothermal reaction on the polystyrene microspheres and the saccharide mixed solution to obtain a reaction product; Carrying out post-treatment on the reaction product to obtain a microsphere powder; Mixing the microsphere powder and a transition metal salt solution to obtain a mixed solution; stirring and standing the mixed solution, and then separating to obtain solid particles; Carrying out heat treatment on the solid particles to obtain a carbide ceramic nanometer hollow sphere.

[0006] Further, the polystyrene dispersion liquid is obtained by mixing polystyrene and ultrapure water; and the mass fraction of the polystyrene dispersion liquid is 8-12 wt.%.

[0007] Further, the saccharide substance is one of glucose, fructose and starch. The use amount ratio of the polystyrene dispersion liquid, water and the saccharide substance is (1.5-3) g:(40-70) mL:(1-3) g.

[0008] Further, the temperature of the hydrothermal reaction is 160-200℃, and the holding time is 6-22h.

[0009] Further, the post-treatment comprises centrifugal treatment, washing treatment and drying treatment in sequence. The washing treatment is to alternately wash with ultrapure water and anhydrous ethanol until the color of the filtrate is colorless.

[0010] Further, the transition metal salt solution is obtained by dissolving a salt substance in a mixed solvent; and the salt substance is one or a combination of multiple of zirconium oxychloride octahydrate, hafnium oxychloride octahydrate, zirconium chloride, hafnium chloride, tantalum chloride, zirconium nitrate, zirconyl nitrate hydrate, zirconium acetate, zirconium sulfate and hafnium sulfate.

[0011] Further, the mixed solvent is anhydrous ethanol and ultrapure water with a volume ratio of 1:3-4:0. The pH value of the transition metal salt solution is 3-5, and the concentration is 0.0005-1 mol / L. The concentration of the microsphere powder added to the mixed solution is 1-10 g / L.

[0012] Furthermore, the solid particles are dried before the heat treatment; the stirring time is 8 to 12 hours, and the standing time is 4 to 10 hours.

[0013] Furthermore, the process parameters of the heat treatment are: in an argon atmosphere, a heating rate not exceeding 3°C / min, a heat treatment temperature of 1700-2000°C, and a time of 2-4 hours.

[0014] The invention also discloses a carbide ceramic hollow nanosphere prepared by the preparation method.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a method for preparing hollow carbide ceramic nanospheres. Polystyrene (PS) is used as a template and combined with a sugar substance and a transition metal salt to prepare hollow nanospheres through a template method. This method can control the diameter of the sphere cavity by using templates of different particle sizes, thereby meeting different environmental and performance requirements, and solving the technical problem that the existing preparation methods are difficult to control the cavity size.

[0016] Furthermore, PS microspheres are selected as templates, which can decompose during the heating process, and the residual carbon rate is much lower than that of microspheres with components such as PMMA, and no other by-products are generated; not only can single-component carbide ultra-high temperature ceramic hollow nanospheres be prepared, but also multi-component and carbide ultra-high temperature solid solution ceramic hollow nanospheres with different proportions can be prepared according to usage requirements, which can be widely used in various fields; at the same time, no catalyst is introduced during the preparation process of this method, which not only reduces the cost of raw materials and simplifies the operation, but also avoids the introduction of impurities, which is beneficial to improving the purity of carbide ultra-high temperature ceramic hollow nanospheres. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The microstructure and surface EDS spectrum of HfC hollow spheres; Among them: (a) TEM image of HfC hollow sphere, surface EDS analysis of Figure (a); (b) C element; (c) Hf element; Figure 2 The morphology of the microsphere powder prepared by hydrothermal reaction of PS microspheres and glucose at 180℃ for 20h; Figure 3 The microstructure and surface EDS spectrum of ZrC hollow spheres; Among them: (a) TEM image of ZrC hollow sphere, surface EDS analysis of Figure (a); (b) Zr element; (c) C element; Figure 4TEM image and surface EDS spectrum of (Hf, Ta)C hollow sphere; Wherein: (a) TEM image of (Hf, Ta)C hollow sphere, surface EDS analysis of figure (a); (b) C element; (c) Hf element; (d) Ta element. DETAILED DESCRIPTION

[0018] To enable persons skilled in the art to understand the features and effects of the present application, the following is a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific words used herein have their usual meanings to those skilled in the art of the present application, and in case of conflict, the definition in the specification shall prevail.

[0019] Theories or mechanisms described and disclosed herein, whether correct or not, should not be considered limiting the scope of the present application, i.e., the present application can be practiced without regard to any particular theory or mechanism.

[0020] Herein, all features defined in the form of numerical ranges or percentage ranges such as values, amounts, contents and concentrations are for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be considered to have encompassed and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0021] Herein, unless otherwise specified, "comprise", "include", "contain", "have" or similar words encompass the meaning of "consist of" and "consist essentially of", for example, "A comprises a" encompasses the meaning of "A comprises a and other" and "A comprises only a".

[0022] Herein, for the sake of brevity, all possible combinations of the technical features in each embodiment or example are not described. Therefore, as long as the combinations of the technical features do not contradict each other, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered as the scope of the present specification.

[0023] The present application provides a preparation method of carbide ceramic nanohollow sphere, comprising the following steps: Step 1: uniformly sized polystyrene (PS) microspheres are added to ultrapure water, and ultrasonic treatment is performed thereon to make the microspheres present in a single particle dispersed state, to obtain a polystyrene dispersion liquid; Step 2: ultrapure water and a saccharide substance are added to the polystyrene dispersion liquid, and then it is placed in a water bath kettle, and stirring treatment is performed thereon at 30-70°C until the saccharide is completely dissolved and the PS microspheres are fully dispersed in the saccharide solution, to obtain a polystyrene microsphere saccharide mixed solution; Step 3: Pour the polystyrene microsphere saccharide mixed solution into a polytetrafluoroethylene liner and place it in a high-pressure reaction kettle for hydrothermal reaction to obtain a reaction product; Step 4: Centrifugal treatment is performed on the reaction product to separate out solid particles, and the particles are washed alternately with ultrapure water and anhydrous ethanol until the filtrate is colorless, and the obtained solid particles are dried to obtain a brownish microsphere powder; Step 5: A certain amount of zirconium, hafnium and tantalum salt substances are dissolved in a mixed solution of anhydrous ethanol and ultrapure water, and a transition metal salt solution is obtained after adjusting the pH of the solution. The microsphere powder is added to the transition metal salt solution, stirred at room temperature for 8-12 h, and then left to stand for 4-10 h. The solid particles are separated and dried. Step 6: The solid particles are heat treated to obtain carbide ultrahigh-temperature ceramic hollow nanospheres.

[0024] Preferably, the mass fraction of the polystyrene dispersion is 8-12 wt.%, and the PS microspheres have no particle size range requirement and are uniform in size.

[0025] Preferably, the saccharide substance can be glucose, fructose and starch; the ratio of polystyrene dispersion: ultrapure water: saccharide substance is 1.5-3 g: 40-70 ml: 1-3 g.

[0026] Preferably, the holding temperature of the hydrothermal reaction is 160-200℃, and the holding time is 6-22 h.

[0027] Preferably, the zirconium, hafnium and tantalum salt substances can be one or more combinations of zirconium oxychloride octahydrate, hafnium oxychloride octahydrate, zirconium chloride, hafnium chloride, tantalum chloride, zirconium nitrate, zirconyl nitrate hydrate, zirconium acetate, zirconium sulfate and hafnium sulfate; the volume ratio of the mixed solution of anhydrous ethanol and ultrapure water is 1:3-4:0; the concentration of the mixed solution of transition metal salts is 0.0005 mol / L-1 mol / L, the solution pH is 3-5, and the concentration of the added microsphere powder is 1-10 g / L.

[0028] Preferably, the heat treatment temperature is 1700-2000℃, the time is 2-4 h, the heating rate cannot exceed 3℃ / min, and the whole process is protected by argon.

[0029] Preferably, the size of the cavity of the carbide ultrahigh-temperature ceramic hollow nanosphere is controlled by the size of the polystyrene microspheres in step 1.

[0030] The application will be further described in conjunction with specific examples. It should be understood that these examples are only used to illustrate the application and not intended to limit the scope of the application. Furthermore, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content of the application, and these equivalent forms also fall within the scope defined by the appended claims.

[0031] The following examples use the instruments and equipment that are conventional in the art. The experimental methods in the following examples, unless otherwise specified, are generally carried out according to conventional conditions, or according to the conditions recommended by the manufacturer. The following examples use various raw materials, unless otherwise specified, all use conventional commercially available products, which are conventional specifications in the art. In the specification of the application and the following examples, unless otherwise specified, "%" means weight percent, "parts" means weight parts, and the ratio means weight ratio.

[0032] Example 1 A preparation method of carbide ceramic nanohollow spheres, comprising the following steps: Step 1: 0.25 g of PS microspheres with a particle size of about 500 nm were added to 2.25 g of ultrapure water, and ultrasonic treatment was performed to make the microspheres present as single particle dispersion, to obtain a 10 wt.% PS microsphere dispersion solution; Step 2: 70 mL of ultrapure water and 1.7 g of starch were added to the PS microsphere dispersion solution, and then it was placed in a water bath kettle for stirring treatment at 60°C until the starch was completely dissolved and the PS microspheres were fully dispersed in the starch solution, to obtain a PS microsphere and starch mixed solution; Step 3: The PS microsphere and starch mixed solution was poured into a polytetrafluoroethylene liner and placed in a high-pressure reaction kettle for hydrothermal reaction at 190°C for 12 h, to obtain a reaction product; Step 4: The reaction product was subjected to centrifugal treatment to separate out solid particles, and was washed alternately with ultrapure water and anhydrous ethanol until the filtrate was colorless, and the obtained solid particles were subjected to drying treatment at 60°C for 24 h, to obtain a brownish microsphere powder; Step 5: 10.7 mg of hafnium oxychloride octahydrate was dissolved in 20 mL of a mixed solution of anhydrous ethanol and ultrapure water with a mass ratio of 3:1, and the solution PH was adjusted to 4, to obtain a transition metal salt solution; 0.03 g of the microsphere powder was added to the transition metal salt solution, and after stirring at room temperature for 12 h and standing for 10 h, the solid particles were separated out and subjected to drying treatment at 60°C for 12 h; Step 6: The dried solid particles were heat treated at 1900°C at a temperature rising rate of 2°C / min for 2 h, to obtain hafnium carbide superhigh-temperature ceramic hollow nanospheres (HfC hollow spheres), as shown in Figure 1 It can be seen from the figure that the hollow spheres have good sphericity, and the cavity diameter is about 500 nm, which is close to the diameter of the PS microsphere template.

[0033] Example 2 A preparation method of a carbide ceramic nanohollow sphere, comprising the following steps: Step 1: 0.16 g of PS microspheres with a particle size of about 100 nm are added into 1.84 g of ultrapure water, and ultrasonic treatment is performed thereon, so that the microspheres are in a single particle dispersed state, to obtain a 8 wt.% PS microsphere dispersion liquid; Step 2: 60 mL of ultrapure water and 2 g of glucose are added into the PS microsphere dispersion liquid, and then the mixture is placed in a water bath kettle and subjected to stirring treatment at 30℃ until the glucose is completely dissolved and the PS microspheres are fully dispersed in the glucose solution, to obtain a PS microsphere and glucose mixed solution; Step 3: The PS microsphere and glucose mixed solution is poured into a polytetrafluoroethylene liner and placed in a high-pressure reaction kettle, and hydrothermal reaction is performed at 180℃ for 20 h, to obtain a reaction product; Step 4: The reaction product is subjected to centrifugal treatment, and the solid particles are separated out and washed alternately with ultrapure water and anhydrous ethanol until the filtrate is colorless, and the obtained solid particles are subjected to drying treatment at 70℃ for 10 h, to obtain a brownish microsphere powder, and the micro-morphology is as shown in Figure 2 It can be seen from the figure that the glucose-coated PS microsphere powder has good monodispersity, the microspheres are not bonded to each other and have no damage phenomenon, and the particle sizes are similar; Step 5: 7.2 g of zirconium oxychloride octahydrate is dissolved in 40 mL of a mixed solution of anhydrous ethanol and ultrapure water with a mass ratio of 1:3, and the PH of the solution is adjusted to 3, to obtain a transition metal salt solution; 0.4 g of the microsphere powder is added into the transition metal salt solution, and after stirring at room temperature for 12 h and standing for 4 h, the solid particles are separated out and subjected to drying treatment at 70℃ for 10 h; Step 6: The dried solid particles are heat-treated at 1800℃ for 2 h at a temperature rising rate of 2℃ / min, to obtain a zirconium carbide super-high-temperature ceramic hollow nanosphere (ZrC hollow sphere), as shown in Figure 3 It can be seen from the figure that the cavity diameter of the hollow sphere is about 100 nm, which is similar to the diameter of the PS microsphere template.

[0034] Example 3 A preparation method of a carbide ceramic nanohollow sphere, comprising the following steps: Step 1: 0.3 g of PS microspheres with a particle size of about 300 nm are added into 2.7 g of ultrapure water, and ultrasonic treatment is performed thereon, so that the microspheres are in a single particle dispersed state, to obtain a 10 wt.% PS microsphere dispersion liquid; Step 2: Add 40 mL of ultrapure water and 2.3 g of starch to the PS microsphere dispersion, then place it in a water bath and stir it at 70°C until the starch is completely dissolved and the PS microspheres are fully dispersed in the starch solution to obtain a mixed solution of PS microspheres and starch; Step 3: Pour the mixed solution of PS microspheres and starch into a polytetrafluoroethylene liner, place it in a high-pressure reactor, and perform hydrothermal reaction at 200°C for 6 hours to obtain a reaction product; Step 4: The reaction product was centrifuged to separate the solid particles, and the solid particles were washed alternately with ultrapure water and anhydrous ethanol until the filtrate was colorless. The solid particles were dried at 70°C for 20 hours to obtain a brown microsphere powder; Step 5: Dissolve 0.23 g of tantalum chloride and 0.58 g of hafnium chloride in 60 mL of anhydrous ethanol and adjust the pH of the solution to 4 to obtain a transition metal salt solution; add 0.2 g of microsphere powder to the transition metal salt solution, stir at room temperature for 10 hours, and then let it stand for 10 hours. Separate the solid particles and dry them at 70°C for 24 hours; Step 6: The dried solid particles are heat treated at 2000°C for 4 h at a heating rate of 2°C / min to obtain hafnium tantalum carbide ultra-high temperature ceramic hollow nanospheres ((Hf, Ta)C hollow spheres). Figure 4 As shown in the figure, it can be seen that the cavity diameter of the hollow sphere is about 300 nm, which is close to the diameter of the PS microsphere template, and the content of Hf element is higher than that of Ta element, which is consistent with the content of the added transition metal salt.

[0035] Example 4 A method for preparing carbide ceramic hollow nanospheres comprises the following steps: Step 1: 0.18 g of PS microspheres with a particle size of approximately 800 nm were added to 1.32 g of ultrapure water and subjected to ultrasonic treatment to disperse the microspheres into single particles, thereby obtaining a 12 wt.% PS microsphere dispersion. Step 2: Add 40 mL of ultrapure water and 1 g of glucose to the PS microsphere dispersion, then place it in a water bath and stir it at 70°C until the glucose is completely dissolved and the PS microspheres are fully dispersed in the glucose solution to obtain a mixed solution of PS microspheres and glucose; Step 3: Pour the mixed solution of PS microspheres and glucose into a polytetrafluoroethylene liner, place it in a high-pressure reactor, and perform hydrothermal reaction at 160°C for 22 hours to obtain a reaction product; Step 4: The reaction product was centrifuged to separate the solid particles, and the solid particles were washed alternately with ultrapure water and anhydrous ethanol until the filtrate was colorless. The solid particles were dried at 70°C for 20 hours to obtain a brown microsphere powder; Step 5: 3.58 g of tantalum chloride was dissolved in 10 mL of anhydrous ethanol and 10 mL of ultrapure water, and the PH of the solution was adjusted to 5 to obtain a transition metal salt solution; 0.02 g of microsphere powder was added to the transition metal salt solution, stirred at room temperature for 8 h, and then placed for 6 h; the solid particles were separated and dried at 70°C for 24 h; Step 6: The dried solid particles were heat treated at 1700°C for 4 h at a heating rate of 2°C / min to obtain tantalum carbide ultra-high temperature ceramic hollow nanospheres.

[0036] Example 5 A preparation method of carbide ceramic nanohollow spheres, comprising the following steps: Step 1: 0.24 g of PS microspheres with a particle size of about 800 nm was added to 2.76 g of ultrapure water, and ultrasonic treatment was performed to make the microspheres present a single particle dispersed state, to obtain a 8 wt.% PS microsphere dispersion liquid; Step 2: 70 mL of ultrapure water and 3 g of glucose were added to the PS microsphere dispersion liquid, and then it was placed in a water bath kettle and stirred at 70°C until the glucose was completely dissolved and the PS microspheres were fully dispersed in the glucose solution, to obtain a PS microsphere and glucose mixed solution; Step 3: The PS microsphere and glucose mixed solution was poured into a polytetrafluoroethylene liner and placed in a high-pressure reaction kettle, and hydrothermal reaction was carried out at 180°C for 20 h to obtain a reaction product; Step 4: The reaction product was centrifuged to separate the solid particles, and ultrapure water and anhydrous ethanol were used to wash alternately until the filtrate was colorless; the obtained solid particles were dried at 70°C for 20 h to obtain brown microsphere powder; Step 5: 7 g of zirconium chloride and 10.75 g of tantalum chloride were dissolved in 30 mL of anhydrous ethanol and 30 mL of ultrapure water, and the PH of the solution was adjusted to 5 to obtain a transition metal salt solution; 0.48 g of microsphere powder was added to the transition metal salt solution, stirred at room temperature for 8 h, and then placed for 6 h; the solid particles were separated and dried at 70°C for 24 h; Step 6: The dried solid particles were heat treated at 1900°C for 4 h at a heating rate of 3°C / min to obtain zirconium tantalum carbide ultra-high temperature ceramic hollow nanospheres.

[0037] The above is only to illustrate the technical idea of the present application, and cannot limit the protection scope of the present application. Any modification made according to the technical idea of the present application on the basis of the technical scheme falls within the protection scope of the claims of the present application.

Claims

1. A method for preparing carbide ceramic hollow nanospheres, characterized in that: The following steps are involved: mixing a polystyrene dispersion with water and a sugar substance to obtain a polystyrene microsphere sugar mixed solution; subjecting the polystyrene microsphere-saccharide mixed solution to a hydrothermal reaction to obtain a reaction product; Post-processing the reaction product to obtain microsphere powder; The microsphere powder and the transition metal salt solution are mixed to obtain a mixed solution; the mixed solution is stirred and allowed to stand, and then solid particles are obtained by separation; The solid particles are heat-treated to obtain carbide ceramic hollow nanospheres.

2. The method for preparing carbide ceramic hollow nanospheres according to claim 1, wherein: The polystyrene dispersion is obtained by mixing polystyrene and ultrapure water; the mass fraction of the polystyrene dispersion is 8-12 wt.%.

3. The method for preparing carbide ceramic hollow nanospheres according to claim 1, wherein: The sugar substance is one of glucose, fructose and starch; The usage ratio of the polystyrene dispersion, water and sugar substance is (1.5-3) g: (40-70) mL: (1-3) g.

4. The method for preparing carbide ceramic hollow nanospheres according to claim 1, wherein: The temperature of the hydrothermal reaction is 160-200° C., and the insulation time is 6-22 hours.

5. The method for preparing carbide ceramic hollow nanospheres according to claim 1, wherein: The post-processing includes centrifugation, washing and drying in sequence; The washing process is to use ultrapure water and anhydrous ethanol to wash alternately until the filtrate is colorless.

6. The method for preparing carbide ceramic hollow nanospheres according to claim 1, wherein: The transition metal salt solution is obtained by dissolving a salt substance in a mixed solvent; the salt substance is one or more combinations of zirconium oxychloride octahydrate, hafnium oxychloride octahydrate, zirconium chloride, hafnium chloride, tantalum chloride, zirconium nitrate, zirconium oxynitrate hydrate, zirconium acetate, zirconium sulfate and hafnium sulfate.

7. The method for preparing carbide ceramic hollow nanospheres according to claim 6, characterized in that: The mixed solvent is anhydrous ethanol and ultrapure water in a volume ratio of 1:3 to 4:0; The pH value of the transition metal salt solution is 3-5, and the concentration is 0.0005-1 mol / L; The concentration of the microsphere powder added to the mixed solution is 1-10 g / L.

8. The method for preparing carbide ceramic hollow nanospheres according to claim 1, wherein: The solid particles are dried before the heat treatment; the stirring time is 8 to 12 hours, and the standing time is 4 to 10 hours.

9. The method for preparing carbide ceramic hollow nanospheres according to claim 1, wherein: The process parameters of the heat treatment are: in an argon atmosphere, a heating rate not exceeding 3°C / min, a heat treatment temperature of 1700-2000°C, and a time of 2-4 hours.

10. A carbide ceramic hollow nanosphere, characterized in that: The method is prepared according to any one of claims 1 to 9.

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