Monodisperse titanium dioxide, its preparation method and use

Abstract

The present application relates to a kind of monodisperse titanium dioxide and its preparation method and application, the preparation method includes, titanate is mixed with mixed solvent to obtain mixture, the mixed solvent is made of ethanol and acetonitrile;Base source is added to mixture, continuous stirring reaction;Stop stirring, aging treatment, obtain monodisperse titanium dioxide.The present application is based on specific ethanol and acetonitrile mixed system, the hydrolysis rate of Ti 4+ Is regulated, the stability of system is maintained, the isotropic growth of TiO2 Grain is provided with support, and it is induced to form regular spherical morphology spontaneously.In addition, the present application can not only shorten the time of stirring reaction by aging treatment, but also make spherical precursor have sufficient time to carry out lattice rearrangement, reduce lattice defect, improve crystallinity, make morphology more regular, surface more smooth at the same time, avoid abnormal grain and adhesion, to obtain monodisperse, uniform particle size spherical TiO2.

Description

Technical Field

[0001] This invention relates to the field of titanium dioxide materials technology, specifically to a monodisperse titanium dioxide, its preparation method, and its applications. Background Technology

[0002] Titanium dioxide (TiO2) microspheres, as a functional material that combines a regular spherical structure with the intrinsic properties of TiO2 (photocatalysis, ultraviolet shielding, and high stability), have broad application prospects in photocatalysis, solar cells, biomedicine and other fields. Their spherical morphology can provide higher specific surface area and more uniform dispersion, which provides important support for the optimization of material functions.

[0003] In recent years, monodisperse TiO2 microspheres have attracted widespread attention from researchers due to their broad application prospects in high-tech fields such as high-performance ceramics, catalysts, and photonic crystals. Currently, methods such as sol-gel, chemical precipitation, microemulsion, hydrolysis, and spray drying are used. Among these, the sol-gel method is the most conventional. However, due to the difficulty in controlling the reaction rate, TiO2 microspheres prepared by the conventional sol-gel method exhibit severe agglomeration, poor dispersibility, and non-uniform size. Some methods have also made corresponding adjustments to the liquid phase system, successfully preparing monodisperse TiO2 microspheres. For example, CN1712357A discloses a method for preparing monodisperse spherical titanium dioxide colloidal particles with controllable size and morphology. Titanate is dissolved in a mixed solvent of anhydrous ethanol and acetonitrile, and water or ammonia is added at low temperature to carry out the reaction, resulting in spherical, monodisperse TiO2 particles with a narrow size distribution. However, this method requires controlling the low-temperature reaction and a relatively long stirring time. CN104211112A discloses a method for preparing uniformly sized micro / nano TiO2 spherical particles. Under room temperature conditions, using titanate as a precursor and acetonitrile and KCl as auxiliary agents, uniformly sized micro / nano TiO2 spherical particles with a diameter distribution of 100-300 nm are prepared via hydrolysis. This method is simple to operate and has mild reaction conditions; however, it requires a large amount of n-propanol and the co-salt KCl.

[0004] Therefore, there is an urgent need to develop a simple, room-temperature, and energy-efficient method for preparing monodisperse TiO2. Summary of the Invention

[0005] To overcome the problems existing in the prior art, the present invention provides a method for preparing monodisperse titanium dioxide, comprising, A mixture is obtained by mixing titanate with a mixed solvent, wherein the mixed solvent is composed of ethanol and acetonitrile; Add the alkali source to the mixture and continue stirring to react; Stop stirring and allow to age to obtain monodisperse titanium dioxide.

[0006] Furthermore, the stirring reaction is carried out at a stirring rate of 200-500 rpm for 20-60 min; The temperatures of the stirring reaction and the aging treatment are both higher than 20°C and lower than 30°C.

[0007] Furthermore, the aging process takes 3-8 hours.

[0008] Furthermore, the volume ratio of the titanate to the mixture is 1:40-60.

[0009] Furthermore, the volume ratio of ethanol to acetonitrile in the mixed solvent is 2-5:1-3.

[0010] Furthermore, the titanate ester and the alkali source are fed by a dropping method, with a dropping rate of 1-5 drops / s; The alkali source is used to adjust the pH of the mixture to 9.0-10.0.

[0011] Furthermore, after the aging process, there is a heat treatment step, which is carried out at 200-350°C for 1-3 hours.

[0012] The present invention also provides a monodisperse titanium dioxide, which is obtained by the above preparation method.

[0013] Furthermore, the monodisperse titanium dioxide is spherical with a particle size of 200-400 nm.

[0014] The present invention also provides the application of the above-mentioned monodisperse titanium dioxide in catalysts, drug carriers, functional fillers, special ceramics, and solar cells.

[0015] Compared with the prior art, the beneficial effects of the present invention include: This invention is based on a specific ethanol and acetonitrile mixture system to regulate Ti 4+ The hydrolysis rate is maintained, thus ensuring the stability of the system and providing support for the isotropic growth of TiO2 grains, inducing their spontaneous formation of regular spherical morphology. Furthermore, the aging treatment in this invention not only shortens the stirring reaction time and eliminates the need for low temperatures, but also allows the spherical precursors sufficient time for lattice rearrangement, reducing lattice defects, increasing crystallinity, and resulting in a more regular morphology and smoother surface, preventing deformed particles and adhesion, thereby obtaining monodisperse, uniformly sized spherical TiO2.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0018] Figure 1 The XRD pattern of the monodisperse titanium dioxide prepared in Example 2 is shown; Figure 2 A scanning electron microscope image of the monodisperse titanium dioxide prepared in Example 1 is shown; Figure 3 A scanning electron microscope image of the monodisperse titanium dioxide prepared in Example 2 is shown; Figure 4 A scanning electron microscope image of the spherical titanium dioxide prepared in Comparative Example 1 is shown; Figure 5 A bar chart showing the particle size distribution of monodisperse titanium dioxide prepared in Example 2 is shown. Figure 6 A scanning electron microscope image of the spherical titanium dioxide prepared in Comparative Example 3 is shown. Figure 7 A scanning electron microscope image of the monodisperse titanium dioxide prepared in Comparative Example 4 is shown. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0020] 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 invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0021] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0022] In a mixed solvent system based on ethanol and acetonitrile, acetonitrile can react with Ti4+ The formation of weak coordination slows down the hydrolysis and polycondensation rate of titanate, preventing the formation of amorphous precipitates. A specific ratio of ethanol maintains the stability of the system, ensuring uniform hydrolysis of the titanate, thus providing a stable environment for the formation of spherical precursors. This invention uses ethanol and acetonitrile as reaction solvents and optimizes their ratio.

[0023] For some existing processes that use ethanol and acetonitrile as reaction solvents, it is still necessary to control the reaction temperature or add organic solvents and inorganic salts. This invention introduces an aging treatment step after controlling the addition of the alkali source to the reaction. The aging treatment not only shortens the stirring reaction time and eliminates the need for the reaction to be carried out at a low temperature, but also allows the spherical precursor sufficient time for lattice rearrangement, reducing lattice defects, improving crystallinity, and making the morphology more regular and the surface smoother, avoiding deformed particles and adhesion, thereby obtaining monodisperse, uniformly sized spherical TiO2.

[0024] In view of this, on the one hand, the present invention provides a method for preparing monodisperse titanium dioxide, comprising, A mixture is obtained by mixing titanate with a mixed solvent, wherein the mixed solvent is composed of ethanol and acetonitrile; Add the alkali source to the mixture and continue stirring to react; Stop stirring and allow to age to obtain monodisperse titanium dioxide.

[0025] In some preferred embodiments, the stirring reaction is carried out at a stirring rate of 200-500 rpm for 20-40 min; The temperatures of the stirring reaction and the aging treatment are both higher than 20°C and lower than 30°C.

[0026] In some preferred embodiments, the aging process takes 3-8 hours.

[0027] In some preferred embodiments, the volume ratio of the titanate to the mixture is 1:40-60.

[0028] It should be noted that the type of titanate in this invention is not strictly limited. For example, titanate includes at least one of tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and tetratert-butyl titanate.

[0029] In some preferred embodiments, the volume ratio of ethanol to acetonitrile in the mixed solvent is 2-5:1-3.

[0030] In some preferred embodiments, the titanate ester and the alkali source are fed by a dropping method, with a dropping rate of 1-5 drops / s; The alkali source is used to adjust the pH of the mixture to 9.0-10.0.

[0031] It should be noted that the alkali source in this invention is not strictly limited. Based on the method of addition, the alkali source can be at least one of alkaline substances such as ammonia, organic bases (ethylenediamine, triethylamine, diisopropylamine, etc.), and inorganic bases (sodium hydroxide, potassium hydroxide, etc.), and / or solutions of these alkaline substances. The solvent of the solution is not strictly limited and can be at least one of water, ethanol, acetone, acetonitrile, etc. Based on the dropwise addition method and reaction control, ammonia is the most preferred alkali source.

[0032] In some preferred embodiments, a heat treatment step is performed after aging, wherein the heat treatment is carried out at 200-350°C for 1-3 hours. Specifically, the heat treatment may be performed using a constant temperature oven or a muffle furnace. To improve the crystallinity of the product, the present invention employs a low-temperature drying method. Drying at a lower temperature, rather than high-temperature (≥500°C) calcination, resolves the contradiction between improving crystallinity and preserving morphology, simplifies the process, reduces energy consumption, and ensures product structural stability, enabling finished product preparation without complex equipment.

[0033] The present invention will be further described in detail below through specific embodiments. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. Where specific techniques or conditions are not specified in the embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments used that do not specify the manufacturer are all conventional products that can be obtained commercially.

[0034] Example 1 A method for preparing monodisperse titanium dioxide includes the following steps: S1. Measure 200 mL of ethanol and 50 mL of acetonitrile into a 500 mL beaker, turn on the magnetic stirrer, adjust the stirring speed to 300 rpm, and stir and mix at 25 °C for 10 min to form a mixed solvent; use a pipette to take 5 mL of tetrabutyl titanate and add it to the mixed solvent that is being stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. The system is transparent at the beginning of the addition. After the addition is completed, continue stirring for 30 min, and it will turn into a pale yellow transparent solution.

[0035] S2. Using a pipette, 1.5 mL of ammonia water is added to the pale yellow transparent solution obtained in step S1, which is stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. After the ammonia water is added, a white precipitate is formed. After the addition is completed, the pH of the mixed system is about 9.5. Continue stirring for 30 min. At this time, the white precipitate in the system settles slightly and there is no obvious aggregation.

[0036] S3. Turn off the magnetic stirrer and stop stirring. Let the beaker stand at 25°C for 6 hours to form a uniform white precipitate layer. After aging, remove the clear solution on the top layer. Wash the remaining white precipitate with deionized water several times and centrifuge. Dry it in an oven at 60°C for 24 hours to obtain the precursor white powder. Finally, sinter the precursor white powder in a muffle furnace at 300°C for 2 hours to obtain monodisperse titanium dioxide.

[0037] Example 2 A method for preparing monodisperse titanium dioxide includes the following steps: S1. Measure 150 mL of ethanol and 100 mL of acetonitrile into a 500 mL beaker, turn on the magnetic stirrer, adjust the stirring speed to 300 rpm, and stir and mix at 25 °C for 10 min to form a mixed solvent; use a pipette to take 5 mL of tetrabutyl titanate and add it to the mixed solvent that is being stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. The system is transparent at the beginning of the addition. After the addition is completed, continue stirring for 30 min, and it will turn into a pale yellow transparent solution.

[0038] S2. Using a pipette, 1.5 mL of ammonia water is added to the pale yellow transparent solution obtained in step S1, which is stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. After the ammonia water is added, a white precipitate is formed. After the addition is completed, the pH of the mixed system is about 9.5. Continue stirring for 30 min. At this time, the white precipitate in the system settles slightly and there is no obvious aggregation.

[0039] S3. Turn off the magnetic stirrer and stop stirring. Let the beaker stand at 25°C for 6 hours to form a uniform white precipitate layer. After aging, remove the clear solution on the top layer. Wash the remaining white precipitate with deionized water several times and centrifuge. Dry it in an oven at 60°C for 24 hours to obtain the precursor white powder. Finally, sinter the precursor white powder in a muffle furnace at 300°C for 2 hours to obtain monodisperse titanium dioxide.

[0040] Example 3 A method for preparing monodisperse titanium dioxide includes the following steps: S1. Measure 125 mL of ethanol and 125 mL of acetonitrile into a 500 mL beaker, turn on the magnetic stirrer, adjust the stirring speed to 300 rpm, and stir and mix at 25 °C for 10 min to form a mixed solvent; use a pipette to take 5 mL of tetrabutyl titanate and add it to the mixed solvent that is being stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. The system is transparent at the beginning of the addition. After the addition is completed, continue stirring for 30 min, and it will turn into a pale yellow transparent solution.

[0041] S2. Using a pipette, 1.5 mL of ammonia water is added to the pale yellow transparent solution obtained in step S1, which is stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. After the ammonia water is added, a white precipitate is formed. After the addition is completed, the pH of the mixed system is about 9.5. Continue stirring for 30 min. At this time, the white precipitate in the system settles slightly and there is no obvious aggregation.

[0042] S3. Turn off the magnetic stirrer and stop stirring. Let the beaker stand at 25°C for 6 hours to form a uniform white precipitate layer. After aging, remove the clear solution on the top layer. Wash the remaining white precipitate with deionized water several times and centrifuge. Dry it in an oven at 60°C for 24 hours to obtain the precursor white powder. Finally, sinter the precursor white powder in a muffle furnace at 300°C for 2 hours to obtain monodisperse titanium dioxide.

[0043] Example 4 A method for preparing monodisperse titanium dioxide includes the following steps: S1. Measure 100 mL of ethanol and 150 mL of acetonitrile into a 500 mL beaker, turn on the magnetic stirrer, adjust the stirring speed to 300 rpm, and stir and mix at 25 °C for 10 min to form a mixed solvent; use a pipette to take 5 mL of tetrabutyl titanate and add it to the mixed solvent that is being stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. The system is transparent at the beginning of the addition. After the addition is completed, continue stirring for 30 min, and it will turn into a pale yellow transparent solution.

[0044] S2. Using a pipette, 1.5 mL of ammonia water is added to the pale yellow transparent solution obtained in step S1, which is stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. After the ammonia water is added, a white precipitate is formed. After the addition is completed, the pH of the mixed system is about 9.5. Continue stirring for 30 min. At this time, the white precipitate in the system settles slightly and there is no obvious aggregation.

[0045] S3. Turn off the magnetic stirrer and stop stirring. Let the beaker stand at 25°C for 6 hours to form a uniform white precipitate layer. After aging, remove the clear solution on the top layer. Wash the remaining white precipitate with deionized water several times and centrifuge. Dry it in an oven at 60°C for 24 hours to obtain the precursor white powder. Finally, sinter the precursor white powder in a muffle furnace at 300°C for 2 hours to obtain monodisperse titanium dioxide.

[0046] Comparative Example 1 A method for preparing spherical titanium dioxide includes the following steps: S1. Measure 150 mL of ethanol and 100 mL of acetonitrile into a 500 mL beaker, turn on the magnetic stirrer, adjust the stirring speed to 300 rpm, and stir and mix at 25 °C for 10 min to form a mixed solvent; use a pipette to take 5 mL of tetrabutyl titanate and add it to the mixed solvent that is being stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. The system is transparent at the beginning of the addition. After the addition is completed, continue stirring for 30 min, and it will turn into a pale yellow transparent solution.

[0047] S2. Using a pipette, add water at a rate of 2 drops / s to the pale yellow transparent solution obtained in step S1, which is stirred continuously at a stirring speed of 300 rpm. After the water is added, a white precipitate is formed. After the addition is complete, the pH of the mixed system is about 7.5. Continue stirring for 30 minutes. At this time, the white precipitate in the system settles slightly and there is no obvious aggregation.

[0048] S3. Turn off the magnetic stirrer and stop stirring. Let the beaker stand at 25°C for 6 hours to form a uniform white precipitate layer. After aging, remove the clear solution on the top layer. Wash the remaining white precipitate with deionized water several times and centrifuge. Dry it in an oven at 60°C for 24 hours to obtain the precursor white powder. Finally, sinter the precursor white powder in a muffle furnace at 300°C for 2 hours to obtain spherical titanium dioxide.

[0049] Comparative Example 2 A method for preparing spherical titanium dioxide includes the following steps: S1. Measure 200 mL of ethanol and 50 mL of acetonitrile into a 500 mL beaker, turn on the magnetic stirrer, adjust the stirring speed to 300 rpm, and stir and mix at 25 °C for 10 min to form a mixed solvent; use a pipette to take 5 mL of tetrabutyl titanate and add it to the mixed solvent that is being stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. The system is transparent at the beginning of the addition. After the addition is completed, continue stirring for 30 min, and it will turn into a pale yellow transparent solution.

[0050] S2. Use a pipette to draw water and add it to the pale yellow transparent solution obtained in step S1, which is stirred continuously at a stirring speed of 300 rpm, at a dropping rate of 2 drops / s. After the water is added, a white precipitate is formed. After the addition is complete, continue stirring for 30 minutes. At this time, the white precipitate in the system has settled slightly and there is no obvious aggregation.

[0051] S3. Turn off the magnetic stirrer and stop stirring. Let the beaker stand at 25°C for 6 hours to form a uniform white precipitate layer. After aging, remove the clear solution on the top layer. Wash the remaining white precipitate with deionized water several times and centrifuge. Dry it in an oven at 60°C for 24 hours to obtain the precursor white powder. Finally, sinter the precursor white powder in a muffle furnace at 300°C for 2 hours to obtain spherical titanium dioxide.

[0052] Comparative Example 3 A method for preparing spherical titanium dioxide includes the following steps: S1. Measure 150 mL of ethanol and 100 mL of acetonitrile into a 500 mL beaker, turn on the magnetic stirrer, adjust the stirring speed to 300 rpm, and stir and mix at 25 °C for 10 min to form a mixed solvent; use a pipette to take 5 mL of tetrabutyl titanate and add it to the mixed solvent that is being stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. The system is transparent at the beginning of the addition. After the addition is completed, continue stirring for 30 min, and it will turn into a pale yellow transparent solution.

[0053] S2. Using a pipette, 1.5 mL of ammonia water is added to the pale yellow transparent solution obtained in step S1, which is stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. After the ammonia water is added, a white precipitate is formed. After the addition is completed, the pH of the mixed system is about 9.5. Continue stirring for 30 min. At this time, the white precipitate in the system settles slightly and there is no obvious aggregation.

[0054] S3. Turn off the magnetic stirrer, remove the clear solution on the top layer, wash the remaining white precipitate with deionized water several times and centrifuge, then dry it in an oven at 60℃ for 24h to obtain the precursor white powder; finally, sinter the precursor white powder in a muffle furnace at 300℃ for 2h to obtain spherical titanium dioxide.

[0055] Comparative Example 4 A method for preparing monodisperse titanium dioxide includes the following steps: S1. Measure 150 mL of ethanol and 100 mL of acetonitrile into a 500 mL beaker, turn on the magnetic stirrer, adjust the stirring speed to 300 rpm, and stir and mix at 25 °C for 10 min to form a mixed solvent; use a pipette to take 5 mL of tetrabutyl titanate and add it to the mixed solvent that is being stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. The system is transparent at the beginning of the addition. After the addition is completed, continue stirring for 30 min, and it will turn into a pale yellow transparent solution.

[0056] S2. Using a pipette, 1.5 mL of ammonia water is added to the pale yellow transparent solution obtained in step S1, which is stirred continuously at a stirring speed of 300 rpm at a dropping rate of 2 drops / s. After the ammonia water is added, a white precipitate is formed. After the addition is completed, the pH of the mixed system is about 9.5. Continue stirring for 30 min. At this time, the white precipitate in the system settles slightly and there is no obvious aggregation.

[0057] S3. Turn off the magnetic stirrer and stop stirring. Let the beaker stand at 25°C for 12 hours to form a uniform white precipitate layer. After aging, remove the clear solution on the top layer. Wash the remaining white precipitate with deionized water several times and centrifuge. Dry it in an oven at 60°C for 24 hours to obtain the precursor white powder. Finally, sinter the precursor white powder in a muffle furnace at 300°C for 2 hours to obtain monodisperse titanium dioxide.

[0058] Test case The crystal structure of the monodisperse titanium dioxide prepared in Example 2 was characterized by XRD. Figure 1 As can be seen, its crystal structure is basically the same as that of anatase titanium dioxide, and there are no impurity peaks, indicating that the prepared monodisperse titanium dioxide has high purity and is anatase type with good crystallinity.

[0059] The microstructure of the titanium dioxide materials obtained in Example 1, Example 2, and Comparative Example 1 was observed using scanning electron microscopy. The results are as follows: Figure 2-4 As shown. Figure 5 The particle distribution of the titanium dioxide material obtained in Example 2 is also shown. It can be seen that the titanium dioxide material prepared in Example 2 has good sphericity, regular morphology, uniform size, and good dispersibility; while Comparative Example 1 exhibits more irregular structures and extremely uneven size distribution; Example 1 shows an aggregated structure of finer spherical particles. Compared to Example 2, the solvent system ratio of Example 1 is different, while Comparative Example 1 uses water as a precipitant. The morphology of the titanium dioxide materials prepared in Comparative Examples 3 and 4 was also observed using scanning electron microscopy. Figure 6 As can be seen, the material obtained in Comparative Example 3 has poor sphericity and very uneven particle distribution. This is because it has not undergone aging treatment, the particle growth has not reached a stable state, and the size is uneven. The subsequent centrifugation operation caused some of the spherical structures to be destroyed. The morphology of the materials in Comparative Example 4 and Example 2 is very similar, which shows that titanium dioxide materials with good sphericity and good dispersibility can be prepared by combining a stirring reaction with a shorter aging time.

[0060] These results demonstrate that only by strictly controlling the specific ratio of the mixed solvent of ethanol and acetonitrile, as well as the specific pH, and through short-term stirring and aging treatment, can monodisperse, uniformly sized spherical titanium dioxide be obtained.

[0061] In summary, this invention, based on a specific ethanol and acetonitrile mixture system, regulates Ti... 4+The hydrolysis rate is maintained, thus ensuring the stability of the system and providing support for the isotropic growth of TiO2 grains, inducing their spontaneous formation of regular spherical morphology. Furthermore, the aging treatment in this invention not only shortens the stirring reaction time and eliminates the need for low temperatures, but also allows the spherical precursors sufficient time for lattice rearrangement, reducing lattice defects, increasing crystallinity, and resulting in a more regular morphology and smoother surface, preventing deformed particles and adhesion, thereby obtaining monodisperse, uniformly sized spherical TiO2.

[0062] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing monodisperse titanium dioxide, characterized in that, include, A mixture is obtained by mixing titanate with a mixed solvent, wherein the mixed solvent is composed of ethanol and acetonitrile; Add the alkali source to the mixture and continue stirring to react; Stop stirring and allow to age to obtain monodisperse titanium dioxide.

2. The method for preparing monodisperse titanium dioxide according to claim 1, characterized in that, The stirring reaction was carried out at a stirring rate of 200-500 rpm for 20-60 min; The temperatures of the stirring reaction and the aging treatment are both higher than 20°C and lower than 30°C.

3. The method for preparing monodisperse titanium dioxide according to claim 1, characterized in that, The aging process takes 3-8 hours.

4. The method for preparing monodisperse titanium dioxide according to claim 1, characterized in that, The volume ratio of the titanate to the mixture is 1:40-60.

5. The method for preparing monodisperse titanium dioxide according to claim 1, characterized in that, The volume ratio of ethanol to acetonitrile in the mixed solvent is 2-5:1-3.

6. The method for preparing monodisperse titanium dioxide according to claim 1, characterized in that, The titanate ester and the alkali source are added by dropping, with a dropping rate of 1-5 drops / s; The alkali source is used to adjust the pH of the mixture to 9.0-10.

0.

7. The method for preparing monodisperse titanium dioxide according to any one of claims 1-6, characterized in that, After aging, there is a heat treatment step, which is carried out at 200-350℃ for 1-3 hours.

8. A monodisperse titanium dioxide, characterized in that, It is obtained by the preparation method according to any one of claims 1-7.

9. The monodisperse titanium dioxide according to claim 8, characterized in that, It is spherical with a particle size of 200-400nm.

10. The application of monodisperse titanium dioxide as described in claim 8 in catalysts, drug carriers, functional fillers, special ceramics, and solar cells.

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