A preparation method of a tin dioxide coated titanium dioxide composite material doped with antimony

Abstract

The application provides a preparation method of a tin-doped antimony-doped tin dioxide coated titanium dioxide composite material, which comprises the following steps: forming an antimony complex solution by adding antimony trioxide into a citric acid-nitric acid mixed solution; adding a sodium stannate aqueous solution and the antimony complex solution into a titanium dioxide slurry drop by drop; adjusting the pH value by using ammonia water; allowing tin and antimony hydrolysis products to heterogeneously nucleate on the surface of titanium dioxide particles and to be in-situ oriented coating; aging, solid-liquid separation, drying and calcination are conducted to obtain a core-shell structure tin-doped antimony-doped tin dioxide coated titanium dioxide (TiO2@ATO) composite material. The preparation method is simple in process, mild in conditions and free of chlorine in the whole process, and the prepared TiO2@ATO composite material has excellent ultraviolet shielding performance of titanium dioxide and good conductivity of ATO, and can be applied to the fields of antistatic coating, photoelectric functional material, catalysis and electrode material.

Description

Technical Field

[0001] This invention belongs to the field of inorganic functional composite materials technology, specifically relating to a method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material. Background Technology

[0002] Antimony-doped tin dioxide (ATO) is a semiconductor material with excellent conductivity and good chemical stability, widely used in conductivity, antistatic, and electromagnetic shielding applications. Traditional ATO preparation methods often use chlorine-containing precursors such as tin tetrachloride and antimony trichloride. Chloride ions can easily remain and corrode equipment, affecting product stability, and the treatment of chlorine-containing wastewater is also challenging. To address the chlorine pollution problem, research has been conducted both domestically and internationally on various chlorine-free systems for ATO preparation. CN101597022A uses metallic tin and antimony trioxide as raw materials, dissolves them in a nitric acid-citric acid system, and prepares pure ATO through ammonia precipitation and calcination, achieving chlorine-free synthesis; CN103011263A uses stannous oxalate as the tin source and tartaric acid to dissolve the antimony source, preparing flake-shaped ATO through liquid-phase precipitation, with improved dispersibility; CN104787796B and CN103641157A, etc., respectively use plasma pyrolysis and solid-phase diffusion doping to prepare ATO with stannate or tin dioxide as chlorine-free precursors, further reducing chloride ion residue; WO2011 / 050748A1 uses sodium stannate and antimony trioxide as raw materials to directly synthesize nano-ATO through hydrothermal method, achieving chlorine-free, low particle size, and highly crystallizable controllable synthesis.

[0003] However, the existing technologies mentioned above are still focused on the preparation of pure-phase ATO powder. The resulting powders are prone to agglomeration and have high costs, and their functions are limited, failing to simultaneously meet the synergistic requirements of conductivity and UV shielding. Currently, composite methods for ATO and titanium dioxide include solid-phase reaction, liquid-phase co-precipitation, and sol-gel. Among these, the sol-gel method has better coating uniformity, but the process steps are cumbersome, the conditions are harsh, and the cost is high. Conventional liquid-phase precipitation methods generally suffer from uneven coating, weak interfacial bonding, and easy generation of free particles. Moreover, most routes still rely on chlorine-containing precursors, making it difficult to balance environmental friendliness and structural stability. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a simple, mild, and chlorine-free method for preparing antimony-doped tin dioxide-coated titanium dioxide composite material, which addresses the shortcomings of the prior art. The method involves growing a dense and uniform ATO shell on the surface of titanium dioxide in situ through heterogeneous nucleation, and systematically optimizing pH, antimony doping amount, calcination temperature, and SnO2 / TiO2 coating ratio to obtain a core-shell composite material with stable structure and excellent synergistic conductivity and ultraviolet shielding performance.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material, comprising the following steps: S1. Dissolve sodium stannate in deionized water and stir to obtain an aqueous solution of sodium stannate. S2. Add antimony trioxide to a citric acid-nitric acid mixed solution and stir to dissolve to form an antimony complex solution; S3. Disperse titanium dioxide powder in deionized water, stir and sonicate to obtain titanium dioxide slurry; S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred and the pH value is adjusted with ammonia. Then, after aging, solid-liquid separation, drying, and calcination, the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO is obtained.

[0006] Preferably, the concentration of the sodium stannate aqueous solution in S1 is 0.01~0.5 mol / L.

[0007] Preferably, the concentration of citric acid in the citric acid-nitric acid mixed solution in S2 is 0.1~1 mol / L, and the concentration of nitric acid is 0.1~1 mol / L.

[0008] Preferably, the molar ratio of antimony to tin is 0.3~0.5, i.e., n Sb :n Sn = (0.3~0.5): 1.

[0009] Preferably, the molar ratio of citric acid to the total amount of tin and antimony is 2 to 6, i.e., n 柠檬酸 :n (Sn+Sb) =(2~6):1.

[0010] Preferably, the temperature at which the antimony complex solution is formed by stirring and dissolving in step S2 is 80~85°C.

[0011] Preferably, the ratio of titanium dioxide powder to deionized water in S3 is 3g:120mL; the power of the ultrasonic treatment is 100~300W, and the time is 30~40min.

[0012] Preferably, the concentration of ammonia in S4 is 12%, and the pH value is adjusted to 7-9.

[0013] Preferably, the aging time in S4 is 4~12h; the drying temperature is 60~100℃ and the time is 3~12h; the calcination temperature is 350~550℃ and the time is 1~8h.

[0014] The present invention also provides an antimony-doped tin dioxide-coated titanium dioxide composite material prepared by the above method.

[0015] Compared with the prior art, the present invention has the following significant technical effects: This invention provides a method for preparing a core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material, which can be applied to fields such as antistatic coatings, optoelectronic functional materials, catalysis and electrode materials, and has the following advantages: (1) The entire process is chlorine-free, environmentally friendly, and has no risk of chloride ion residue; (2) Directional coating is achieved through heterogeneous nucleation, resulting in a continuous and dense ATO shell with high coating uniformity; (3) It combines the excellent UV shielding properties of titanium dioxide with the good conductivity of ATO, resulting in a significant synergistic effect; (4) The particle dispersibility is better than that of pure ATO, which is more conducive to subsequent processing and application.

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a SEM image of the TiO2@ATO composite material of Example 1 of the present invention; Figure 2 This is a TEM image of the TiO2@ATO composite material of Example 1 of the present invention; Figure 3 This is the XRD pattern of the TiO2@ATO composite material of Example 1 of the present invention; Figure 4 This is the UV-Vis image of the TiO2@ATO composite material of Example 1 of the present invention; Figure 5 This is the XRD pattern of the TiO2@ATO composite material of Example 2 of the present invention; Figure 6 This is the XRD pattern of the TiO2@ATO composite material of Example 3 of the present invention; Figure 7 This is the XRD pattern of the TiO2@ATO composite material of Example 4 of the present invention; Figure 8 This is the UV-Vis image of the TiO2@ATO composite material of Comparative Example 1 of this invention; Figure 9 This is the UV-Vis image of the TiO2@ATO composite material of Comparative Example 2 of this invention; Figure 10 This is a SEM image of the TiO2@ATO composite material of Comparative Example 3 of the present invention; Figure 11 This is a SEM image of the TiO2@ATO composite material of Comparative Example 4 of the present invention. Detailed Implementation

[0018] Example 1

[0019] This embodiment describes a method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material. Sb / n Sn =0.35, n 柠檬酸 :n (Sn+Sb) ≈3.51:1, including the following steps: S1. At room temperature, 1.59 g of sodium stannate (Na2SnO3·3H2O, molar amount of tin n) is added. Sn =0.005961mol) was added to a 100mL beaker, and 50mL of deionized water was added. The mixture was stirred and dissolved to obtain an aqueous solution of sodium stannate (concentration of 0.11922mol / L). S2. Add 5.43 g of citric acid (C6H8O7, 0.02826 mol) to 50 mL of deionized water, heat to 70 °C, and add 1 mL of 68% concentrated nitric acid to obtain a citric acid-nitric acid mixed solution (citric acid and nitric acid concentrations are 0.554 mol / L and 0.296 mol / L, respectively); then add 0.305 g of antimony trioxide (Sb2O3, molar amount of antimony n) to the citric acid-nitric acid mixed solution. Sb =0.0021mol), stirred at 85℃ until completely dissolved, to obtain an antimony complex solution (Sb(III)-citric acid complex solution formed by dissolving Sb2O3 in a citric acid-nitric acid system). S3. Weigh 3 g of TiO2 powder and add it to 120 mL of deionized water. After stirring, sonicate at 100 W for 40 min to obtain a highly dispersed titanium dioxide slurry. S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously and slowly added dropwise to the titanium dioxide slurry obtained in S3. During the addition process, continuous stirring is maintained, and the pH is adjusted to 7.5 with 12% ammonia water. This allows the tin and antimony hydrolysis products to heterogeneously nucleate and in-situ directionally coat the titanium dioxide particles. After the addition is complete, the mixture is aged for 5 hours. The resulting product is filtered, dried at 80℃ for 5 hours, and calcined at 550℃ for 2 hours to obtain a core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO (coating amount 30%). The coating amount is calculated based on the ratio of the mass of the reaction product SnO2 to the mass of TiO2 added before the reaction.

[0020] Figure 1 This is a SEM image of the TiO2@ATO composite material prepared in this embodiment. The TiO2 matrix with a particle size of 120-300nm is completely covered, and there is a dense and uniform ATO particle coating layer on the surface, forming a regular core-shell structure. The coating layer has a consistent and continuous thickness, with no exposed part of the matrix.

[0021] Figure 2 This is a TEM image of the TiO2@ATO composite material prepared in this embodiment, with a coating thickness of 9.8-18.5 nm and a particle size of 4-7 nm.

[0022] Figure 3 The image shows the XRD pattern of the TiO2@ATO composite material prepared in this embodiment. Diffraction peaks consistent with SnO2 and TiO2 can be observed, indicating that the material has good crystallinity. No diffraction peaks of antimony and related compounds were observed, indicating that antimony did not form compounds, but was doped into the tin dioxide lattice in the form of doping.

[0023] Figure 4 This is the UV-vis image of the TiO2@ATO composite material prepared in this embodiment. It has good absorption performance in the ultraviolet light range and good transmittance in the visible light range.

[0024] Example 2

[0025] This embodiment describes a method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material. The main difference from Example 1 is the calcination time in step S4, which includes the following steps: S1. At room temperature, add 1.59g of sodium stannate to a 100mL beaker, add 50mL of deionized water, stir to dissolve and obtain an aqueous solution of sodium stannate; S2. Add 5.43g of citric acid to 50mL of deionized water, heat to 70℃, add 1mL of 68% concentrated nitric acid to obtain a citric acid-nitric acid mixed solution; then add 0.305g of antimony trioxide to the citric acid-nitric acid mixed solution, stir at 80℃ until completely dissolved to obtain an antimony complex solution. S3. Weigh 3g of TiO2 powder and add it to 120mL of deionized water. After stirring, sonicate at 200W for 35min to obtain a highly dispersed titanium dioxide slurry. S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously and slowly added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred, and the pH is adjusted to 7.5 with 12% ammonia water. This allows the tin and antimony hydrolysis products to heterogeneously nucleate and in-situ directionally coat the titanium dioxide particles. After the dropwise addition is complete, the mixture is aged for 4 hours. The resulting product is filtered, dried at 100℃ for 3 hours, and calcined at 550℃ for 1 hour to obtain the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO.

[0026] Figure 5 This is the XRD pattern of the TiO2@ATO composite material prepared in this embodiment.

[0027] Example 3

[0028] This embodiment describes a method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material. The main difference from Example 1 is the calcination time in step S4, which includes the following steps: S1. At room temperature, add 1.59g of sodium stannate to a 100mL beaker, add 50mL of deionized water, stir to dissolve and obtain an aqueous solution of sodium stannate; S2. Add 5.43g of citric acid to 50mL of deionized water, heat to 70℃, add 1mL of 68% concentrated nitric acid to obtain a citric acid-nitric acid mixed solution; then add 0.305g of antimony trioxide to the citric acid-nitric acid mixed solution, stir at 81℃ until completely dissolved to obtain an antimony complex solution. S3. Weigh 3 g of TiO2 powder and add it to 120 mL of deionized water. After stirring, sonicate at 200 W for 35 min to obtain a highly dispersed titanium dioxide slurry. S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously and slowly added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred, and the pH is adjusted to 7.5 with 12% ammonia water. This allows the tin and antimony hydrolysis products to heterogeneously nucleate and in-situ directionally coat the titanium dioxide particles. After the dropwise addition is complete, the mixture is aged for 6 hours. The resulting product is filtered, dried at 90℃ for 4 hours, and calcined at 550℃ for 4 hours to obtain the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO.

[0029] Figure 6 This is the XRD pattern of the TiO2@ATO composite material in this embodiment.

[0030] Example 4

[0031] This embodiment describes a method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material. The main difference from Example 1 is the calcination temperature in step S4, and the method includes the following steps: S1. At room temperature, add 1.59g of sodium stannate to a 100mL beaker, add 50mL of deionized water, stir to dissolve and obtain an aqueous solution of sodium stannate; S2. Add 5.43g of citric acid to 50mL of deionized water, heat to 70℃, add 1mL of 68% concentrated nitric acid to obtain a citric acid-nitric acid mixed solution; then add 0.305g of antimony trioxide to the citric acid-nitric acid mixed solution, stir at 82℃ until completely dissolved to obtain an antimony complex solution. S3. Weigh 3 g of TiO2 powder and add it to 120 mL of deionized water. After stirring, sonicate at 200 W for 35 min to obtain a highly dispersed titanium dioxide slurry. S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously and slowly added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred, and the pH is adjusted to 7.5 with 12% ammonia water. This allows the tin and antimony hydrolysis products to heterogeneously nucleate and in-situ directionally coat the titanium dioxide particles. After the dropwise addition is complete, the mixture is aged for 10 hours. The resulting product is filtered, dried at 60°C for 12 hours, and calcined at 350°C for 2 hours to obtain the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO.

[0032] Figure 7 This is the XRD pattern of the TiO2@ATO composite material prepared in this embodiment.

[0033] Comparative Example 1 A method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material differs from Example 1 mainly in that the amount of antimony doping is different (n). Sb / n Sn =0.15), including the following steps: S1. At room temperature, add 1.59g of sodium stannate to a 100mL beaker, add 50mL of deionized water, stir to dissolve and obtain an aqueous solution of sodium stannate; S2. Add 5.43g of citric acid to 50mL of deionized water, heat to 70℃, add 1mL of 68% concentrated nitric acid to obtain a citric acid-nitric acid mixed solution; then add 0.13g of antimony trioxide to the citric acid-nitric acid mixed solution, stir at 85℃ until completely dissolved to obtain an antimony complex solution. S3. Weigh 3 g of TiO2 powder and add it to 120 mL of deionized water. After stirring, sonicate at 300 W for 30 min to obtain a highly dispersed titanium dioxide slurry. S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously and slowly added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred, and the pH is adjusted to 8.5 with 12% ammonia water. This allows the tin and antimony hydrolysis products to heterogeneously nucleate and in-situ directionally coat the titanium dioxide particles. After the dropwise addition is complete, the mixture is aged for 5 hours. The resulting product is filtered, dried at 80°C for 5 hours, and calcined at 550°C for 2 hours to obtain the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO.

[0034] Figure 8 This is the UV-vis image of the TiO2@ATO composite material prepared in Comparative Example 1.

[0035] Comparative Example 2 A method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material differs from Example 1 mainly in that the amount of antimony doping is different (n). Sb / nSn = 0.75), including the following steps: S1. At room temperature, add 1.59g of sodium stannate to a 100mL beaker, add 50mL of deionized water, stir to dissolve and obtain an aqueous solution of sodium stannate; S2. Add 5.43g of citric acid to 50mL of deionized water, heat to 70℃, add 1mL of 68% concentrated nitric acid to obtain a citric acid-nitric acid mixed solution; then add 0.65g of antimony trioxide to the citric acid-nitric acid mixed solution, stir at 85℃ until completely dissolved to obtain an antimony complex solution. S3. Weigh 3 g of TiO2 powder and add it to 120 mL of deionized water. After stirring, sonicate at 300 W for 30 min to obtain a highly dispersed titanium dioxide slurry. S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously and slowly added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred, and the pH is adjusted to 8.5 with 12% ammonia water. This allows the tin and antimony hydrolysis products to heterogeneously nucleate and in-situ directionally coat the titanium dioxide particles. After the dropwise addition is complete, the mixture is aged for 5 hours. The resulting product is filtered, dried at 80°C for 5 hours, and calcined at 550°C for 2 hours to obtain the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO.

[0036] Figure 9 This is the UV-vis image of the TiO2@ATO composite material prepared in Comparative Example 2.

[0037] Comparative Example 3 The preparation method of an antimony-doped tin dioxide-coated titanium dioxide composite material differs from Example 1 mainly in the coating amount. The coating ratio is adjusted based on a SnO2 / TiO2 ratio of 50%. The change in the amount of antimony trioxide is to ensure that the Sb doping amount remains constant, i.e., n... Sb / n Sn =0.35, the change in the amount of citric acid is also to maintain the ratio of citric acid to tin and antimony at a constant level, including the following steps: S1. At room temperature, add 2.65g of sodium stannate to a 100mL beaker, add 50mL of deionized water, and stir to dissolve to obtain an aqueous solution of sodium stannate (concentration of 0.1987mol / L). S2. Add 9.03 g of citric acid to 50 mL of deionized water, heat to 70 °C, add 1 mL of 68% concentrated nitric acid to obtain a citric acid-nitric acid mixed solution; then add 0.51 g of antimony trioxide to the citric acid-nitric acid mixed solution, stir at 83 °C until completely dissolved to obtain an antimony complex solution. S3. Weigh 3 g of TiO2 powder and add it to 120 mL of deionized water. After stirring, sonicate at 100 W for 40 min to obtain a highly dispersed titanium dioxide slurry. S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously and slowly added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred, and the pH is adjusted to 8.5 with 12% ammonia water. This allows the tin and antimony hydrolysis products to heterogeneously nucleate and in-situ directionally coat the titanium dioxide particles. After the dropwise addition is complete, the mixture is aged for 5 hours. The resulting product is filtered, dried at 80°C for 5 hours, and calcined at 550°C for 2 hours to obtain the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO.

[0038] Figure 10 This is a SEM image of the TiO2@ATO composite material prepared in Comparative Example 3.

[0039] Comparative Example 4 A method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material involves changing the coating amount. The coating ratio is adjusted based on a SnO2 / TiO2 ratio of 10%. The change in the amount of antimony trioxide is to ensure that the Sb doping amount remains constant, i.e., n... Sb / n Sn =0.35, the change in the amount of citric acid is also to maintain the ratio of citric acid to tin and antimony at a constant level, including the following steps: S1. At room temperature, add 0.53g of sodium stannate to a 100mL beaker, add 50mL of deionized water, and stir to dissolve to obtain an aqueous solution of sodium stannate (concentration of 0.03974mol / L). S2. Add 1.81g of citric acid to 50mL of deionized water, heat to 70℃, add 1mL of 68% concentrated nitric acid to obtain a citric acid-nitric acid mixed solution; then add 0.1g of antimony trioxide to the citric acid-nitric acid mixed solution, stir at 80℃ until completely dissolved to obtain an antimony complex solution. S3. Weigh 3g of TiO2 powder and add it to 120mL of deionized water. After stirring, sonicate at 100W for 40min to obtain a highly dispersed titanium dioxide slurry. S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously and slowly added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred, and the pH is adjusted to 7.5 with 12% ammonia water. This allows the tin and antimony hydrolysis products to heterogeneously nucleate and in-situ directionally coat the titanium dioxide particles. After the dropwise addition is complete, the mixture is aged for 5 hours. The resulting product is filtered, dried at 80°C for 5 hours, and calcined at 550°C for 2 hours to obtain the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO.

[0040] Figure 11 This is a SEM image of the TiO2@ATO composite material in Comparative Example 4.

[0041] The resistivity test results of the TiO2@ATO composite materials prepared in Examples 1-4 and Comparative Examples 1-4 are shown in Table 1: Table 1 Resistivity Test Results

[0042] Comparing the effects of antimony doping amount on the conductivity of TiO2@ATO composite materials, it was found that the antimony doping amount in Comparative Example 1 was small, resulting in limited charge carriers for the formation of n-type semiconductor ATO and a higher resistivity; while the antimony doping amount in Comparative Example 2 was too large, which also led to an increase in the resistivity of the material.

[0043] Comparing the effects of ATO coating amount on the conductivity of TiO2@ATO composite materials, it was found that when the coating amount in Comparative Example 3 was too large (50%), the resistivity decreased, but the prepared conductive material was dark in color, which limited its application range. Moreover, the SEM image showed that ATO agglomeration was severe and caused waste of raw materials. Comparative Example 4 had a low coating amount of only 10%, resulting in poor conductivity.

[0044] This invention prepares a core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material, TiO2@ATO. The preparation method is simple, mild, and chlorine-free throughout the process. The resulting TiO2@ATO composite material combines the excellent UV shielding performance of titanium dioxide with the good conductivity of ATO, and can be applied in fields such as antistatic coatings, optoelectronic functional materials, catalysis, and electrode materials.

[0045] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing an antimony-doped tin dioxide-coated titanium dioxide composite material, characterized in that, Includes the following steps: S1. Dissolve sodium stannate in deionized water and stir to obtain an aqueous solution of sodium stannate. S2. Add antimony trioxide to a citric acid-nitric acid mixed solution and stir to dissolve to form an antimony complex solution; S3. Disperse titanium dioxide powder in deionized water, stir and sonicate to obtain titanium dioxide slurry; S4. The sodium stannate aqueous solution obtained in S1 and the antimony complex solution obtained in S2 are simultaneously added dropwise to the titanium dioxide slurry obtained in S3. During the dropwise addition, the mixture is continuously stirred and the pH value is adjusted with ammonia. Then, after aging, solid-liquid separation, drying, and calcination, the core-shell structured antimony-doped tin dioxide-coated titanium dioxide composite material TiO2@ATO is obtained.

2. The method according to claim 1, characterized in that, The concentration of the sodium stannate aqueous solution mentioned in S1 is 0.01~0.5mol / L.

3. The method according to claim 1, characterized in that, The concentration of citric acid in the citric acid-nitric acid mixed solution described in S2 is 0.1~1 mol / L, and the concentration of nitric acid is 0.1~1 mol / L.

4. The method according to claim 1, characterized in that, The molar ratio of antimony to tin is 0.3 to 0.

5.

5. The method according to claim 4, characterized in that, The molar ratio of citric acid to the total of tin and antimony is 2 to 6.

6. The method according to claim 1, characterized in that, The temperature at which the antimony complex solution is formed by stirring and dissolving in S2 is 80~85℃.

7. The method according to claim 1, characterized in that, The ratio of titanium dioxide powder to deionized water in S3 is 3g:120mL; the ultrasonic treatment power is 100~300W, and the time is 30~40min.

8. The method according to claim 1, characterized in that, The concentration of ammonia in S4 is 12%, and the pH value is adjusted to 7-9.

9. The method according to claim 1, characterized in that, The aging time in S4 is 4~12h; the drying temperature is 60~100℃ and the time is 3~12h; the calcination temperature is 350~550℃ and the time is 1~8h.

10. An antimony-doped tin dioxide-coated titanium dioxide composite material prepared by the method according to any one of claims 1 to 9.

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