A method to improve the conductivity of TiO2@ATO spherical nanoparticles

Abstract

This invention discloses a method for improving the conductivity of TiO2@ATO spherical nanoparticles. The method includes: preparing TiO2 / ATO blended spherical particles as the matrix particles using a hydrothermal method; and coating the prepared TiO2 / ATO blended particles with ATO using a chemical co-precipitation method to obtain highly conductive TiO2@ATO spherical nanoparticles. This invention replaces the poorly conductive TiO2 as the matrix material of traditional TiO2@ATO nanoparticles with a more conductive TiO2 / ATO blend before ATO coating. Overall, compared to traditional TiO2@ATO nanoparticles prepared solely using a chemical co-precipitation method, the inherent drawback of insufficient particle conductivity due to uneven ATO coating on the outer surface is mitigated. Furthermore, compared to TiO2 / ATO blended particles prepared solely using a blending method to modify TiO2, the ATO conductive layer coating the outer surface improves the conductivity of the TiO2@ATO nanoparticles.

Description

Technical Field

[0001] This invention belongs to the field of conductive materials, and specifically relates to a method for preparing conductive nanomaterials. Background Technology

[0002] With technological advancements, functional materials are increasingly being applied across various industries, including clothing, agriculture, and aerospace. However, many polymer materials commonly used in these industries, such as synthetic fibers, rubber, and plastics, are non-conductive and poorly hydrophilic, making them prone to static charge buildup due to everyday contact, impacts, and friction. Because these materials have high resistivity, this static charge cannot be directly eliminated but accumulates on the surface, leading to severe electrostatic buildup. When triggered by external forces, the stored static energy is released, potentially causing a series of accidents. For example, people often experience discomfort due to static electricity generated by synthetic fiber clothing in daily life. More seriously, in the petrochemical industry, static electricity is frequently generated and accumulated during the production, transportation, storage, and use of many products. Electrostatic discharge can easily cause fires or even explosions, disrupting normal production and endangering personal safety. Therefore, reducing the potential static hazards of polymer materials has become a key research focus in related industries. The development and application of conductive and antistatic technologies, as the main methods and approaches to solving this problem, have gradually become an indispensable industry. Currently, industrial production primarily achieves product conductivity by adding conductive materials to the matrix material. Among these, traditional conductive fillers, such as carbon black, offer advantages like excellent conductivity, strong corrosion resistance, and low cost; however, their dark and limited color restricts their application. Titanium dioxide (TiO2) is a light-colored functional material with excellent physicochemical properties. A novel light-colored conductive material can be created by coating the surface of TiO2 with antimony tin oxide (ATO). However, the uneven distribution of ATO on the TiO2 surface during coating results in insufficient conductivity in the final product. Therefore, a method is needed to improve the conductivity of TiO2@ATO nanoparticles. Summary of the Invention

[0003] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0004] In view of the problems existing in the above and / or prior art, the present invention is proposed.

[0005] One objective of this invention is to provide a method for improving the conductivity of TiO2@ATO spherical nanoparticles, the resulting functional material having excellent conductivity and a light color.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing highly conductive TiO2@ATO spherical nanoparticles, comprising,

[0007] TiO2 / ATO blended spherical particles were prepared as substrate particles, and then ATO was coated onto the prepared TiO2 / ATO blended particles by chemical coprecipitation. Finally, highly conductive TiO2@ATO spherical nanoparticles were obtained.

[0008] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, the method for preparing TiO2 / ATO blended spherical particles is a hydrothermal method, comprising: preparing a mixed solution of ethanol (C2H5OH) and water (H2O) as a reaction solution, and then adding nitric acid to adjust the pH value of the solution. Tin tetrachloride (SnCl4-5H2O) and antimony trichloride (SbCl3) are added to the reaction aqueous solution and stirred continuously, and ultrasonically treated to better dissolve them. Then, titanium isopropoxide (C... 12 H 28 O4Ti) was added dropwise to the reaction aqueous solution while continuously stirring. Next, an aqueous solution of ammonium persulfate ((NH4)S2O8) was added to the reaction aqueous solution. After the solution temperature stabilized, stirring continued to gradually form a polymer precursor. The formed gel-like copolymer precursor was then vacuum-dried at room temperature and subsequently calcined in air. After grinding, a blended oxide powder was obtained.

[0009] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, in the hydrothermal method for preparing TiO2 / ATO blended spherical particles, the reaction solution composition is C2H5OH:H2O = 1:1 to 1:10, and nitric acid is added to make the solution pH 0.7.

[0010] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, in the hydrothermal method for preparing TiO2 / ATO blended spherical particles, the molar ratio of Ti:Sn in the reaction system is 15:1 to 2.5:1, and the molar ratio of Sn:Sb is 12:1.

[0011] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, in the hydrothermal method for preparing TiO2 / ATO blended spherical particles, the reaction temperature is 60-80℃ and the reaction time is 1-3h.

[0012] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, in the hydrothermal method for preparing TiO2 / ATO blended spherical particles, the calcination temperature of the polymer precursor is 400-800℃.

[0013] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, wherein: the chemical co-precipitation method includes,

[0014] Prepare sodium hydroxide solution as a precipitant;

[0015] Tin tetrachloride and antimony trichloride are added to a hydrogen peroxide solution as coating agents. During the preparation process, the solution needs to be stirred continuously and hydrochloric acid is added dropwise to dissolve the solid particles in the coating agent.

[0016] The prepared TiO2 / ATO blend spherical particles were placed in deionized water and ultrasonically dispersed to form a suspension. The suspension was then heated with constant stirring to prevent particle agglomeration. As the temperature rose, a prepared coating agent was added, along with a sodium hydroxide precipitant to stabilize the pH. After all the coating agent was added, heating and stirring continued. Finally, the suspension was thoroughly washed with deionized water until no Cl- was present, and then vacuum dried. The dried particles were then calcined.

[0017] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, in the chemical coprecipitation method, after the temperature of the suspension is increased, a prepared coating agent is added to start the reaction, wherein the temperature of the suspension is 60℃~100℃.

[0018] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, in the chemical coprecipitation method, a precipitant sodium hydroxide solution needs to be added simultaneously with the addition of the coating agent to stabilize the pH value of the reaction solution, wherein the pH value is 1 to 3.

[0019] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, in the chemical coprecipitation method, after all the coating agent is added, heating and stirring are continued, wherein the stirring time is 1.5h to 2.5h.

[0020] As a preferred embodiment of the method for preparing highly conductive TiO2@ATO spherical nanoparticles according to the present invention, in the chemical coprecipitation method, the dried particles are calcined at a temperature of 400–800°C.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] This invention replaces the poorly conductive TiO2 substrate of traditional TiO2@ATO nanoparticles with a more conductive TiO2 / ATO blend, followed by ATO coating. Overall, compared to traditional TiO2@ATO nanoparticles prepared solely by chemical co-precipitation, the inherent drawback of insufficient particle conductivity due to uneven ATO coating on the outer surface is mitigated. Furthermore, compared to TiO2 / ATO blends prepared solely by modifying TiO2 through blending, the ATO conductive layer on the outer surface enhances the conductivity of the TiO2@ATO nanoparticles. Detailed Implementation

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the examples in the specification.

[0024] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0025] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0026] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0027] Example 1

[0028] (1) Preparation of substrate particles, namely TiO2 / ATO blend spherical particles. A mixed solution of ethanol (C2H5OH) and water (H2O) was prepared as the reaction solution, wherein C2H5OH:H2O = 1:8, and then nitric acid was added to adjust the pH of the solution to 0.7. Tin tetrachloride (SnCl4-5H2O) and antimony trichloride (SbCl3) were added to the reaction aqueous solution and stirred continuously, and sonicated for 0.5 h for better dissolution. The molar ratio of Ti:Sn was 10:1, and the molar ratio of Sn:Sb was 12:1. Then 0.02M titanium isopropoxide (C 12 H 28O4Ti) was added dropwise to the reaction aqueous solution while continuously stirring. Then, a 5 wt% (NH4)S2O8 aqueous solution was added as an initiator to the reaction aqueous solution, bringing the concentration of ammonium persulfate in the mixed solution to 0.25 mol / L. The mixed solution was continuously heated and stirred at 80°C for 2 hours to gradually form a polymer precursor. The resulting gel-like copolymer precursor was then vacuum dried at room temperature for 10 hours, followed by calcination at 600°C in air for 3 hours. After grinding, the blended oxide powder was obtained.

[0029] (2) ATO coating of the substrate particles was performed using a chemical co-precipitation method. First, a 10% sodium hydroxide solution was prepared as a precipitant. Then, tin tetrachloride (SnCl4-5H2O) and antimony trichloride (SbCl3) were weighed out as coating agents according to a Sn:Sb molar ratio of 10:1, and added to a 10wt% hydrogen peroxide (H2O2) solution. Simultaneously, hydrochloric acid was added dropwise to the solution with continuous stirring until the coating agents were fully dissolved. Meanwhile, the prepared substrate particles (TiO2 / ATO blended spherical particles) were placed in deionized water and thoroughly dispersed into a suspension under ultrasonic treatment. The suspension was then transferred to a three-necked flask and continuously stirred and heated. Once the suspension temperature reached 90℃, the prepared coating agent (a mixed solution of SnCl4 and SbCl3) was added. A precipitant (NaOH solution) was added simultaneously with the addition of the coating agent to maintain the pH of the solution at 2. After all the coating agent has been added, continue heating and stirring for 2 hours to fully mature the hydrolysis product. Then, thoroughly wash the resulting suspension until no Cl- is present, and then dry it in a vacuum oven.

[0030] (3) The dried particles were calcined at 600℃ to obtain highly conductive TiO2@ATO spherical nanoparticles.

[0031] Example 2

[0032] The difference from Example 1 is that in step (1), an aqueous solution of ethanol with C2H5OH:H2O = 1:1 is used as the reaction solution for preparing the substrate blend particles.

[0033] Example 3

[0034] The difference from Example 1 is that in step (1), an aqueous solution of ethanol with C2H5OH:H2O = 1:10 is used as the reaction solution for preparing the substrate blend particles.

[0035] Example 4

[0036] The difference from Example 1 is that in step (1), the molar ratio of Ti:Sn is controlled to be 15:1 when preparing TiO2 / ATO blend particles.

[0037] Example 5

[0038] The difference from Example 1 is that the molar ratio of Ti:Sn is controlled to be 2.5:1 when preparing TiO2 / ATO blend particles in step (1).

[0039] Example 6

[0040] The difference from Example 1 is that the hydrothermal reaction time for preparing TiO2 / ATO blend particles in step (1) is 1 h.

[0041] Example 7

[0042] The difference from Example 1 is that the hydrothermal reaction time for preparing TiO2 / ATO blend particles in step (1) is 3 hours.

[0043] Example 8

[0044] The difference from Example 1 is that the temperature of calcining the polymer precursor in step (1) is 400°C.

[0045] Example 9

[0046] The difference from Example 1 is that the temperature of calcining the polymer precursor in step (1) is 800°C.

[0047] Example 10

[0048] The difference from Example 1 is that the reaction temperature for the chemical coprecipitation method of ATO coating in step (2) is 60°C.

[0049] Example 11

[0050] The difference from Example 1 is that the reaction temperature of the chemical coprecipitation method for ATO coating in step (2) is 100°C.

[0051] Example 12

[0052] The difference from Example 1 is that the pH of the reaction solution for the ATO-coated chemical coprecipitation method in step (2) is 1.

[0053] Example 13

[0054] The difference from Example 1 is that the pH of the reaction solution for the ATO-coated chemical coprecipitation method in step (2) is 3.

[0055] Example 14

[0056] The difference from Example 1 is that the reaction time for the chemical coprecipitation method of ATO coating in step (2) is 1.5 h.

[0057] Example 15

[0058] The difference from Example 1 is that the reaction time for the chemical coprecipitation method of ATO coating in step (2) is 2.5 h.

[0059] Example 16

[0060] The difference from Example 1 is that in step (3), the dried particles are calcined at a temperature of 400°C.

[0061] Example 17

[0062] The difference from Example 1 is that in step (3), the dried particles are calcined at a temperature of 800°C.

[0063] Performance testing

[0064] The resistivity of the highly conductive TiO2@ATO spherical nanoparticles prepared in Examples 1 to 17 was tested to observe their conductivity. The testing method was as follows: the sample powder was pressed into thin discs less than 4 mm thick using a 20 mm diameter mold at 30 MPa, and the thickness of the discs was measured using vernier calipers. The resistivity was measured using a four-probe tester, and the resistivity calculation formula (1) is as follows:

[0065]

[0066] In the formula, ρ is the sample resistivity (Ω·cm); D is the sample diameter (mm); S is the average probe spacing (mm); W is the sample thickness (mm); and F... sp F(D / S) is the probe spacing correction factor; F(W / S) is the sample diameter correction factor; F(W / S) is the sample thickness correction factor; I is the current of probes 1 and 4, uA; U is the voltage between probes 2 and 3, uV.

[0067] As can be seen from Examples 1 to 3 and Examples 6 to 9, changing the experimental conditions for preparing the substrate particles will affect the conductivity of the final TiO2@ATO spherical nanoparticles. The best results were obtained by using the conditions in Example 1, where the ratio of ethanol to water was 1:8, the reaction time was 2 hours, and the calcination temperature of the polymer precursor was 600°C.

[0068] As shown in Examples 1, 4, and 5, changing the Ti:Sn molar ratio during the preparation of the substrate particles affects the conductivity and morphology of the final TiO2@ATO spherical nanoparticles. As the Ti:Sn molar ratio decreases and the Sn content increases, the conductivity of the TiO2@ATO spherical nanoparticles gradually improves, but the molding of the substrate particles becomes more difficult. When the Ti:Sn molar ratio is too small, the substrate particles have very small particle sizes and easily form irregular polyhedra, making them difficult to effectively coat in subsequent processes and utilize effectively. Therefore, the Ti:Sn molar ratio of 10:1 in Example 1, which produces spherical substrate particles, yields the best overall effect.

[0069] Table 1

[0070] <![CDATA[Resistivity of TiO2@ATO spherical nanoparticles kΩ·cm]]> Example 1 8kΩ·cm Example 2 10kΩ·cm Example 3 13kΩ·cm Example 4 30kΩ·cm Example 5 1kΩ·cm Example 6 11kΩ·cm Example 7 9kΩ·cm Example 8 35kΩ·cm Example 9 30kΩ·cm Example 10 13kΩ·cm Example 11 11kΩ·cm Example 12 22kΩ·cm Example 13 25kΩ·cm Example 14 14kΩ·cm Example 15 9kΩ·cm Example 16 35kΩ·cm Example 17 29kΩ·cm

[0071] Based on Examples 1 and 10 to 17, it can be seen that changing the experimental conditions during ATO coating will affect the conductivity of the final TiO2@ATO spherical nanoparticles. The best results were obtained by using the reaction temperature of 90°C, the pH value of the reaction solution of 2, the reaction time of 2h, and the calcination temperature of the dried particles of 600°C in Example 1.

[0072] Comparative Example 1

[0073] The difference from Example 1 is that the molar ratio of Ti:Sn was controlled to be 20:1 when preparing the TiO2 / ATO blend particles in step (1). The resistivity of the finally prepared TiO2@ATO spherical nanoparticles was approximately 39 kΩ·cm.

[0074] Comparative Example 2

[0075] The difference from Example 1 is that the temperature of calcining the polymer precursor in step (1) is 200°C, and the resistivity of the TiO2@ATO spherical nanoparticles prepared in the end is about 38 kΩ·cm.

[0076] Comparative Example 3

[0077] The difference from Example 1 is that the temperature of calcining the polymer precursor in step (1) is 900℃, and the resistivity of the TiO2@ATO spherical nanoparticles obtained in the end is about 37kΩ·cm.

[0078] Comparative Example 4

[0079] The difference from Example 1 is that the pH of the reaction solution for the chemical coprecipitation method of ATO coating in step (2) is 7, and the resistivity of the TiO2@ATO spherical nanoparticles obtained is about 45 kΩ·cm.

[0080] Comparative Example 5

[0081] The difference from Example 1 is that in step (3), the dried particles are calcined at a temperature of 200°C, and the resistivity of the TiO2@ATO spherical nanoparticles obtained is approximately 40 kΩ·cm.

[0082] Comparative Example 6

[0083] The difference from Example 1 is that in step (3), the dried particles are calcined at a temperature of 200°C, and the resistivity of the TiO2@ATO spherical nanoparticles obtained is approximately 38 kΩ·cm.

[0084] Table 2

[0085]

[0086]

[0087] During the hydrothermal preparation of substrate particles, as the molar ratio of Ti:Sn increases, the content of ATO with good conductivity in the substrate particles decreases, resulting in a decrease in the overall conductivity of the substrate particles.

[0088] When preparing TiO2@ATO nanoparticles, the calcination temperature in both the substrate particle preparation and ATO coating processes should be controlled at around 600℃. As the calcination temperature increases, the Sb entering the SnO2 lattice... 3+ Transform into Sb 5+ The increasing concentration of ATO leads to a higher concentration of conductive free electrons, thereby enhancing the conductivity of the powder. Furthermore, the increased calcination temperature densifies ATO, reducing the contact resistance between SnO2 crystals and further improving the powder's conductivity. When the calcination temperature is below 600℃, Sb enters the SnO2 lattice... 3+ Only a small amount was converted to Sb. 5+ Furthermore, the contact resistance between SnO2 particles is relatively high, resulting in poor electrical conductivity. When the calcination temperature exceeds 600℃, the Sb doped in SnO2 undergoes oxidation under high-temperature conditions. 5+ Transform into Sb 3+ It may precipitate in the form of Sb2O4, which would actually reduce the concentration of conductive free electrons; and high temperature would cause TiO2 to undergo a crystal transformation, which would be detrimental to the coating of ATO.

[0089] When coating with ATO, the pH of the reaction solution should be controlled to around 2. At low pH, hydration occurs on the particle surface, forming a stable, positively charged (H+) layer. +The hydration film of a particle is disrupted by the increasing OH- concentration as the pH rises. This disrupts the hydration film, catalyzing aggregation and leading to particle size growth. When the OH- concentration reaches a certain level, the particles become negatively charged and reach a stable state, making it difficult for the crystals to aggregate and grow. Therefore, excessively high pH levels result in a rapid hydrolysis reaction, making uniform nucleation difficult to avoid. This not only causes agglomeration but also hinders the uniform coating of crystals on the particles, resulting in poor electrical conductivity of the product.

[0090] Comparative Example 7

[0091] The difference from Example 1 is that the substrate particles were not blended and modified, and the substrate particles coated with ATO were replaced with pure TiO2 particles. The resistivity of the TiO2@ATO spherical nanoparticles prepared in the end was about 40 kΩ·cm.

[0092] Comparative Example 8

[0093] The difference from Example 1 is that the blended modified substrate particles were not coated with ATO, and the resistivity of the final TiO2@ATO spherical nanoparticles was about 25 kΩ·cm.

[0094] When coating substrate particles with ATO using the chemical co-precipitation method, the ATO distribution on the surface of the substrate particles becomes uneven, making it difficult to form continuous conductive pathways. This results in poor conductivity of TiO2@ATO nanoparticles. However, after modifying the substrate particles by blending them with TiO2 / ATO particles, which have higher conductivity, the previously exposed component on the surface of the TiO2@ATO nanoparticles changes from TiO2 to TiO2 / ATO. Since TiO2 / ATO has better conductivity, it is easier for it to form continuous conductive pathways with the ATO layer on the outer surface, thus enhancing the conductivity of the final TiO2@ATO nanoparticle product.

[0095] Even without coating the outer surface of the substrate particles with ATO, although the uniform distribution of the TiO2 / ATO components within the substrate particles can form continuous conductive pathways, the conductivity of TiO2 / ATO is still lower than that of ATO, a material with excellent conductivity. Therefore, coating the outer surface of the TiO2 / ATO substrate particles with ATO can enhance the conductivity of the particles.

[0096] Table 3

[0097] <![CDATA[Preparation method of TiO2 conductive particles]]> resistivity <![CDATA[Chemical co-precipitation method (TiO2@ATO particles)]]> 40kΩ·cm Comparative Example 7 <![CDATA[Blending method (TiO2 / ATO particles)]]> 25kΩ·cm Comparative Example 8 <![CDATA[Blending method + chemical coprecipitation method (TiO2@ATO particles)]]> 8kΩ·cm Example 1

[0098] Comparative Example 9

[0099] The difference from Example 1 is that ammonium persulfate, the initiator, was not used when preparing the substrate particles, and the resistivity of the TiO2@ATO spherical nanoparticles obtained was approximately 39 kΩ·cm.

[0100] An initiator is a substance that can initiate a chemical reaction by providing activation energy or altering the activity of reactants. Initiators play a crucial role in chemical reactions, polymerization reactions, and other processes. Ammonium persulfate, a common thermal initiator, generates free radicals by heating the reaction system, providing the energy required for the reaction and thus initiating it. Without an initiator, the reaction is difficult to initiate when preparing substrate particles, making it challenging to generate uniformly blended substrate particles. Furthermore, the conductive pathways within the substrate particles are often discontinuous, resulting in poor conductivity of the final product. This invention discloses a method for preparing highly conductive TiO2@ATO spherical nanoparticles, including using more conductive TiO2 / ATO blended nanoparticles as substrate particles to replace traditional TiO2 for ATO coating, ultimately producing highly conductive TiO2@ATO spherical nanoparticles.

[0101] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the present invention.

Claims

1. A method for improving the conductivity of TiO2@ATO spherical nanoparticles, characterized in that: include, TiO2 / ATO blended spherical particles were prepared by hydrothermal method as matrix particles. The prepared TiO2 / ATO blended particles were coated with ATO by chemical coprecipitation method to obtain highly conductive TiO2@ATO spherical nanoparticles. The hydrothermal method for preparing TiO2 / ATO involves mixing ethanol and water, adding nitric acid to stabilize the pH of the solution, and using this solution as the reaction solution. Add tin tetrachloride and antimony trichloride to the reaction solution, stir and sonicate, then add titanium isopropoxide dropwise and continue stirring. Then add 4wt%~6wt% of ammonium persulfate aqueous solution to make the concentration of ammonium persulfate in the mixed solution 0.2~0.3mol / L. The mixed solution was heated and stirred to form a colloidal copolymer precursor. The formed colloidal copolymer precursor was vacuum dried at room temperature, calcined and ground in air atmosphere to obtain TiO2 / ATO blended spherical particles. The mass ratio of ethanol to water was 1:1 to 1:10, and nitric acid was added to stabilize the pH of the solution at 0.

7. The mixture is heated and stirred, wherein the heating temperature is 60~80℃ and the time is 1~3h.

2. The method for improving the conductivity of TiO2@ATO spherical nanoparticles as described in claim 1, characterized in that: In the hydrothermal reaction system for preparing TiO2 / ATO blended spherical particles, the molar ratio of Ti:Sn is 15:1 to 2.5:1, and the molar ratio of Sn:Sb is 12:

1.

3. The method for improving the conductivity of TiO2@ATO spherical nanoparticles as described in claim 1, characterized in that: The calcination temperature in the hydrothermal method is 400~800℃.

4. The method for improving the conductivity of TiO2@ATO spherical nanoparticles as described in claim 1, characterized in that: The process of coating the prepared TiO2 / ATO blend particles with ATO using a chemical coprecipitation method is as follows: TiO2 / ATO blended spherical particles were ultrasonically treated in deionized water until completely dispersed into a suspension. The suspension was then heated and stirred. As the temperature of the suspension increased, a coating agent was added dropwise, while sodium hydroxide solution was added to stabilize the pH of the reaction solution. After the coating agent was completely added, heating and stirring continued to obtain the post-reaction suspension, which was then washed with deionized water until Cl-free. - After being placed in the vacuum, the dried particles are calcined.

5. The method for improving the conductivity of TiO2@ATO spherical nanoparticles as described in claim 4, characterized in that: After the temperature of the suspension is raised, a coating agent is added dropwise, and sodium hydroxide solution is added at the same time to stabilize the pH value of the reaction solution. The pH value of the reaction solution is stabilized at 1~3, and the temperature is 60~100℃.

6. The method for improving the conductivity of TiO2@ATO spherical nanoparticles as described in claim 4, characterized in that: The coating agent is prepared by adding tin tetrachloride and antimony trichloride to a hydrogen peroxide solution, stirring continuously, and adding hydrochloric acid dropwise to dissolve the solid.

7. The method for improving the conductivity of TiO2@ATO spherical nanoparticles as described in claim 4, characterized in that: The stirring time for the chemical coprecipitation method is 1.5h to 2.5h, and the calcination temperature is 400 to 800℃.

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