A uranium-containing antimonate tungstate, its preparation method and application

Abstract

The present invention provides a uranium-containing antimony tungstate, a preparation method thereof and an application thereof, belonging to the technical field of new polyacid chemistry materials, and is used to enrich the research on the proton conduction performance of uranium-containing antimony tungstate and improve its proton conductivity. The chemical formula of the present invention is (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O, belonging to the triclinic system, space group P-1, and the unit cell parameters are: #imgabs0##imgabs1#α = 89.1980(10)°, β = 89.5610(10)°, γ = 83.9440(10)°, #imgabs2##imgabs3#Z = 1. Using (NH4) 18 [NaSb9W 21 O 86 ·24H2O, sodium tungstate and uranyl nitrate as raw materials, a uranium-containing antimony tungstate is obtained through a water bath heating reaction. The material has a clear structure, good stability, and proton conduction performance, and its preparation process is simple and easy to operate.

Description

Technical Field

[0001] The present invention belongs to the technical field of new polyoxometalate chemistry materials, and particularly relates to a uranium-containing antimony tungstate and a preparation method and application thereof. Background Art

[0002] With the rapid development of industry, proton exchange membrane fuel cells have received extensive attention due to their advantages such as environmental friendliness, good stability, and high performance (N. Ogiwara, T. Iwano, T. Ito, S. Uchida, Chem. Soc. Rev. 2022, 462, 214524.). Polyoxometalates (POMs for short) are a large class of high-nuclear metal-oxygen clusters formed by the connection of transition metal elements such as Mo, W, V, etc. with oxygen atoms. They have structural diversity and tunable functions and have developed rapidly in applications such as catalysis, medicine, and magnetism (M. T. Pope, A. Müller, Angew. Chem. Int. Ed. Engl. 1991, 30, 34-48; H. N. Miras, J. Yan, D.-L. Long, L. Cronin, Chem. Soc. Rev. 2012, 41, 7403-7430; L. Qin, R. Wang, X. Xin, M. Zhang, T. Liu, H. Lv, G.-Y. Yang, Appl. Catal. B Environ. 2022, 312, 121386; M. Lu, M. Zhang, J. Liu, T.-Y. Yu, J.-N. Chang, L.-J. Shang, S.-L. Li, Y.-Q. Lan, J. Am. Chem. Soc. 2022, 144, 1861-1871.). Polyoxometalates have relatively high thermal stability and can provide a large number of proton hopping sites, and are widely used in proton exchange fuel cells (Y.-Q. Jiao, H.-Y. Zang, X.-L. Wang, E.-L. Zhou, B.-Q. Song, C.-G. Wang, K.-Z Shao, Z.-M. Su, Chem. Commun. 2015, 51, 11313-11316; J.-C. Liu, Q. Han, L.-J. Chen, J.-W. Zhao, C. Streb, Y.-F. Song, Angew. Chem. Int. Ed. 2018, 57, 8416-8420; N. Osamu, K. Teruo, O. Isao, M. Yoshizo, Chem. Lett. 1979, 8, 17-18; K.-D. Kreuer, Chem. Mater. 1996, 8, 610-641.). At the same time, the unique "pseudo-liquid phase" behavior of polyoxometalates is their unique advantage as proton-conducting materials (S.-S. Wang, G.-Y. Yang, Chem. Rev. 2015, 115, 4893-4962.).Meanwhile, the Lewis basicity of oxygen atoms can form cation-cation interactions with the Lewis acidity of metal cation centers, thus acting as hydrogen bond acceptors to form excellent proton conductivity (D. Gui, W. Duan, J. Shu, F. Zhai, N. Wang, X. Wang, J. Xie, H. Li, L. Chen, J. Diwu, Z. Chai, S. Wang, CCS Chem. 2019, 1, 197-206.). Therefore, under appropriate temperature and humidity conditions, polyoxometalate-based materials can exhibit excellent proton conduction properties.

[0003] In the early stage, our research group disclosed a ternary heterometallic antimony tungstate and its preparation method in Patent CN116462717A for the proton conduction properties of polyoxometalate-based materials, and obtained good proton conduction properties (2.3×10 -2 S cm -1 ), and the following research was carried out to further expand the polyoxometalate-based conductive material system and improve the conductivity of uranium-containing antimony tungstate. SUMMARY OF THE INVENTION

[0004] Aiming at the technical problem of the lack of research on the proton conduction properties of uranium-containing antimony tungstate, the present invention provides a uranium-containing antimony tungstate, its preparation method and application. The preparation method of the uranium-containing antimony tungstate of the present invention has low cost, simple and safe preparation process, and is easy to operate. Moreover, the prepared uranium-containing antimony tungstate has proton conduction characteristics, so it has potential application value in the field of POM proton conductive materials.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A uranium-containing antimony tungstate, with the chemical formula (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O, belonging to the triclinic system, with the space group P-1, and the unit cell parameters are: α = 89.1980(10)°, β = 89.5610(10)°, γ = 83.9440(10)°, Z = 1.

[0007] The structure of the uranium-containing antimony tungstate is described as follows: the uranium-containing antimony tungstate contains a dimeric [(UO2)2(H2O)2(SbW9O 33 )2(Sb(OH))2] 10- anion, ten ammonium ions and 31 lattice water molecules. [(UO2)2(H2O)2(SbW9O 33 )2(Sb(OH))2] 10-The anion is composed of two [SbW9O 33 Sb(OH)] 7- units connected by sharing UO2 2+ cations, and the two UO2 2 + ions are adjacent in position. [SbW9O 33 Sb(OH)] 7- The anion can be regarded as composed of {SbO3} units bonded to the three - vacant Keggin - type [SbW9O 33 9- units through two μ2 - O atoms. Among them, uranium has a seven - coordinate pentagonal bipyramid configuration, and the acyl O groups of the UO2 2+ cation are arranged approximately perpendicularly. One oxygen atom in the equatorial position comes from the coordinated water molecule, and the remaining 4 oxygen atoms come from the terminal oxygen atoms of two [SbW9O 33 9- units respectively. [(UO2)2(H2O)2(SbW9O 33 )2(Sb(OH))2] 10- The anion as a whole forms a structure similar to a bow - tie shape. In the [SbW9O 33 Sb(OH)] 7- unit, the Sb atom has a three - coordinate trigonal pyramid geometry. In [(UO2)2(H2O)2(SbW9O 33 )2(Sb(OH))2] 10- the anion, the four Sb atoms are arranged in a trapezoid, the distance between Sb1 - Sb4 is the distance between Sb2 - Sb3 is There is an angle of 43.357° between the two [SbW9O 33 Sb(OH)] 7- units; the bond length of the U = O bond in the UO2 2+ cation is in the range of , the O = U = O bond angles are 176.471° and 175.697°, and the O = U - O bond angle range is 85.72° - 96.193°.

[0008] The uranium - containing antimony tungstate is prepared by a conventional aqueous solution method. The specific steps are as follows:

[0009] Dissolve (NH4) 18 [NaSb9W 21 O 86 ​​Dissolve [[ID=]]·24H2O in water, then add Na2WO4·2H2O, and adjust the pH to 4.3 - 5.0 with acetic acid. Subsequently, add an aqueous solution of uranyl nitrate, and adjust the pH to 3.0 - 3.8 with hydrochloric acid. Then add ammonium chloride, and finally heat for reaction. After the reaction solution cools to room temperature, filter it, and let the clear filtrate stand and volatilize at room temperature to obtain uranyl antimonotungstate crystals.

[0010] Further, the molar ratio of (NH4) 18 [NaSb9W 21 O 86 ·24H2O, Na2WO4, UO2(NO3)2·6H2O and NH4Cl is 1:4:(3 - 5):110.

[0011] Further, the acetic acid solution is prepared by diluting glacial acetic acid, with a concentration of 6 mol / L; the hydrochloric acid solution is prepared by diluting 37% concentrated hydrochloric acid, with a concentration of 3 mol / L; the concentration of the UO2(NO3)2·6H2O aqueous solution is 1 mol / L.

[0012] Further, the temperature of the reaction is 50 - 60 °C, the time is 0.5 - 2 h; the standing and volatilization time is 10 - 20 days.

[0013] Further, the application of the uranyl antimonotungstate in a proton conductive material.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1. In the present invention, the polyacid raw material (NH4) 18 [NaSb9W 21 O 86 ·24H2O reacts with uranyl nitrate to synthesize uranyl antimonotungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O, enriching the structural diversity.

[0016] 2. The preparation method of the uranyl antimonotungstate prepared in the present invention adopts a conventional aqueous solution preparation method. After the reaction is completed, it can be obtained by simple post-treatment operations such as standing and volatilization. The cost is low, the preparation process is safe and simple, and it is easy to operate.

[0017] 3. The structure of the uranyl antimonotungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O prepared in the present invention is clear. The conductivity of the uranyl antimonotungstate reaches 8.68×10 -2 S cm -1, which has good proton conduction performance. The abundant oxygen atoms of antimonotungstate can form interactions with uranyl ions and further form an intermolecular hydrogen bond network with crystal water molecules, providing transmission sites for protons, enabling the uranium-containing antimonotungstate prepared by the present invention to have excellent proton conduction performance and showing potential application value in polyoxometalate-based conductive materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 is the structural diagram of the uranium-containing antimonotungstate of the present invention, where a is the ball-and-stick diagram of the [SbW9O 33 9- unit; b is the ball-and-stick diagram of the {SbO3} unit; c is the geometric configuration of the U atom; d and e are the polyhedron / ball-and-stick schematic diagrams of the uranium-containing antimonotungstate anion of the present invention; f is the position of the {SbO3} unit in the compound; g is the dihedral angle between the [SbW9O 33 Sb(OH)] 7- units.

[0020] Figure 2 Among them: (a) Impedance spectra of the uranium-containing antimonotungstate at 25 °C and different humidities of 45%, 55%, 65%, 75% and 85%; (b) Relationship diagram of the conductivity of the uranium-containing antimonotungstate versus humidity; (c) Impedance spectra of the uranium-containing antimonotungstate at 85% humidity and different temperatures of 25 °C, 35 °C, 45 °C, 55 °C, 65 °C, 75 °C and 85 °C; (d) Curve of linear fitting by the Arrhenius equation.

[0021] Figure 3 are the infrared spectra (a) and X-ray powder diffraction patterns (b) of the uranium-containing antimonotungstate of the present invention before and after proton conduction testing. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] Example 1

[0024] ​Preparation method of ammonium-containing uranium antimonotungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O is as follows:

[0025] (1) Preparation of acetic acid solution (6.0 mol·L -1 ): Dilute 5.0 mL of glacial acetic acid with distilled water to 15.0 mL; Preparation of hydrochloric acid solution (3.0 mol·L -1 ): Dilute 3.0 mL of 37% concentrated hydrochloric acid with distilled water to 12.0 mL; Preparation of UO2(NO3)2·6H2O solution (1.0 mol·L -1 ): Dissolve 5.02 g of uranyl nitrate (UO2(NO3)2·6H2O) in 10.0 mL of distilled water.

[0026] (2) Under stirring conditions, dissolve 1.209 g of (NH4) 18 [NaSb9W 21 O 86 ·24H2O in 100.0 mL of water, add 0.25 g of Na2WO4·2H2O, stir at room temperature for 30 min, then adjust the pH to 4.7 with the acetic acid solution prepared in step (1), stir for 20 min, add 0.5 mL of the UO2(NO3)2·6H2O solution prepared in step (1), adjust the pH to 3.4 with the hydrochloric acid solution prepared in step (1), and continue to stir for 10 min, then add 1.0 g of NH4Cl. React at 50 °C for 1 h, cool and filter, and let stand for 15 days to obtain yellow crystals, with a yield of about 25% (based on UO2(NO3)2·6H2O).

[0027] Among them, the molar ratio of the reaction raw materials (NH4) 18 [NaSb9W 21 O 86 ·24H2O, Na2WO4, UO2(NO3)2·6H2O and NH4Cl is 1:4:3:110.

[0028] Example 2

[0029] Preparation method of ammonium-containing uranium antimonotungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O is as follows:

[0030] (1) Preparation of acetic acid solution (6.0 mol·L -1Preparation of (): Dilute 5.0 mL of glacial acetic acid with distilled water to 15.0 mL; hydrochloric acid solution (3.0 mol·L -1 Preparation of (): Dilute 3.0 mL of 37% concentrated hydrochloric acid with distilled water to 12.0 mL; UO2(NO3)2·6H2O solution (1.0 mol·L -1 Preparation of (): Dissolve 5.02 g of uranyl nitrate (UO2(NO3)2·6H2O) in 10.0 mL of distilled water.

[0031] (2) Under stirring conditions, dissolve 1.209 g of (NH4) 18 [NaSb9W 21 O 86 ·24H2O in 100.0 mL of water, add 0.25 g of Na2WO4·2H2O, stir at room temperature for 30 min, then adjust the pH to 4.7 with the acetic acid solution prepared in step (1), stir for 20 min, add 0.5 mL of the UO2(NO3)2·6H2O solution prepared in step (1), adjust the pH to 3.4 with the hydrochloric acid solution prepared in step (1), and continue to stir for 10 min, then add 1.0 g of NH4Cl. React at 60 °C for 0.5 h, cool and filter, and let stand for 15 days to obtain yellow crystals, with a yield of about 20% (based on UO2(NO3)2·6H2O).

[0032] Among them, the molar ratio of the reaction raw materials (NH4) 18 [NaSb9W 21 O 86 ·24H2O, Na2WO4, UO2(NO3)2·6H2O, and NH4Cl is 1:4:3:110.

[0033] Example 3

[0034] The preparation method of the uranium-containing antimonotungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O in this example is as follows:

[0035] (1) Preparation of acetic acid solution (6.0 mol·L -1 ): Dilute 5.0 mL of glacial acetic acid with distilled water to 15.0 mL; hydrochloric acid solution (3.0 mol·L -1 ): Dilute 3.0 mL of 37% concentrated hydrochloric acid with distilled water to 12.0 mL; UO2(NO3)2·6H2O solution (1.0 mol·L -1 ): Dissolve 5.02 g of uranyl nitrate (UO2(NO3)2·6H2O) in 10.0 mL of distilled water.

[0036] (2) Under stirring conditions, dissolve 1.209 g of (NH4) 18 [NaSb9W 21 O 86 ·24H2O in 100.0 mL of water, add 0.25 g of Na2WO4·2H2O, stir at room temperature for 30 min, then adjust the pH to 4.7 with the acetic acid solution prepared in step (1), stir for 20 min, add 0.5 mL of the UO2(NO3)2·6H2O solution prepared in step (1), adjust the pH to 3.4 with the hydrochloric acid solution prepared in step (1), and continue to stir for 10 min, then add 1.0 g of NH4Cl. React at 50 °C for 2 h, cool and filter, and let stand for 15 days to obtain yellow crystals with a yield of about 18% (based on UO2(NO3)2·6H2O).

[0037] Among them, the molar ratio of the reaction raw materials (NH4) 18 [NaSb9W 21 O 86 ·24H2O, Na2WO4, UO2(NO3)2·6H2O and NH4Cl is 1:4:3:110.

[0038] Example 4

[0039] The preparation method of the uranium-containing antimonotungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O in this example is as follows:

[0040] (1) Preparation of acetic acid solution (6.0 mol·L -1 ): Dilute 5.0 mL of glacial acetic acid with distilled water to 15.0 mL; Preparation of hydrochloric acid solution (3.0 mol·L -1 ): Dilute 3.0 mL of 37% concentrated hydrochloric acid with distilled water to 12.0 mL; Preparation of UO2(NO3)2·6H2O solution (1.0 mol·L -1 ): Dissolve 5.02 g of uranyl nitrate (UO2(NO3)2·6H2O) in 10.0 mL of distilled water.

[0041] (2) Under stirring conditions, dissolve 1.209 g of (NH4) 18 [NaSb9W 21 O 86Dissolve 24H2O in 100.0 mL of water, add 0.25 g of Na2WO4·2H2O, stir at room temperature for 30 min, then adjust the pH to 4.3 with the acetic acid solution prepared in step (1), stir for 20 min, add 0.7 mL of the UO2(NO3)2·6H2O solution prepared in step (1), adjust the pH to 3.8 with the hydrochloric acid solution prepared in step (1), continue to stir for 10 min, and then add 1.0 g of NH4Cl. React at 55 °C for 1 h, cool, filter, and let stand for 10 days to obtain yellow crystals with a yield of approximately 18% (based on UO2(NO3)2·6H2O).

[0042] Among them, the reaction raw materials (NH4) 18 [NaSb9W 21 O 86 ·24H2O, Na2WO4, UO2(NO3)2·6H2O, and NH4Cl have a molar ratio of 1:4:4:110.

[0043] Example 5

[0044] The preparation method of the uranium-containing antimony tungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O in this example is as follows:

[0045] (1) Preparation of acetic acid solution (6.0 mol·L -1 ): Dilute 5.0 mL of glacial acetic acid with distilled water to 15.0 mL; Preparation of hydrochloric acid solution (3.0 mol·L -1 ): Dilute 3.0 mL of 37% concentrated hydrochloric acid with distilled water to 12.0 mL; Preparation of UO2(NO3)2·6H2O solution (1.0 mol·L -1 ): Dissolve 5.02 g of uranyl nitrate (UO2(NO3)2·6H2O) in 10.0 mL of distilled water.

[0046] (2) Under stirring conditions, add 1.209 g of (NH4) 18 [NaSb9W 21 O 86Dissolve [[ID=]]·24H2O in 100.0 mL of water, add 0.25 g of Na2WO4·2H2O, stir at room temperature for 30 min, then adjust the pH to 5.0 with the acetic acid solution prepared in step (1), stir for 20 min, add 0.8 mL of the UO2(NO3)2·6H2O solution prepared in step (1), adjust the pH to 3.0 with the hydrochloric acid solution prepared in step (1), continue to stir for 10 min, and then add 1.0 g of NH4Cl. React at 50 °C for 1 h, cool, filter, and let stand for 15 days to obtain yellow crystals with a yield of about 11% (based on UO2(NO3)2·6H2O).

[0047] Among them, the molar ratio of the reaction raw materials (NH4) 18 [NaSb9W 21 O 86 ·24H2O, Na2WO4, UO2(NO3)2·6H2O, and NH4Cl is 1:4:5:110.

[0048] Example 6

[0049] The preparation method of the uranium-containing antimonotungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O in this example is as follows:

[0050] (1) Preparation of acetic acid solution (6.0 mol·L -1 ): Dilute 5.0 mL of glacial acetic acid with distilled water to 15.0 mL; Preparation of hydrochloric acid solution (3.0 mol·L -1 ): Dilute 3.0 mL of 37% concentrated hydrochloric acid with distilled water to 12.0 mL; Preparation of UO2(NO3)2·6H2O solution (1.0 mol·L -1 ): Dissolve 5.02 g of uranyl nitrate (UO2(NO3)2·6H2O) in 10.0 mL of distilled water.

[0051] (2) Under stirring conditions, add 1.209 g of (NH4) 18 [NaSb9W 21 O 86Dissolve [[ID=]]·24H2O in 100.0 mL of water, add 0.25 g of Na2WO4·2H2O, stir at room temperature for 30 min, then adjust the pH to 4.3 with the acetic acid solution prepared in step (1), stir for 20 min, add 0.8 mL of the UO2(NO3)2·6H2O solution prepared in step (1), adjust the pH to 3.0 with the hydrochloric acid solution prepared in step (1), continue to stir for 10 min, and then add 1.0 g of NH4Cl. React at 50 °C for 1 h, cool, filter, and let stand for 20 days to obtain yellow crystals with a yield of about 21% (based on UO2(NO3)2·6H2O).

[0052] Among them, the molar ratio of the reaction raw materials (NH4) 18 [NaSb9W 21 O 86 ·24H2O, Na2WO4, UO2(NO3)2·6H2O, and NH4Cl is 1:4:5:110.

[0053] Structure identification

[0054] Testing the product prepared in Example 1 above, it can be known that the chemical formula of the product is (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O. The structure diagram of the uranium antimony tungstate of the present invention is as shown Figure 1 below, Figure 1 where a is the ball-and-stick diagram of the [SbW9O 33 9- unit; b is the ball-and-stick diagram of the {SbO3} unit; c is the geometric configuration of the U atom; d and e are the polyhedron / ball-and-stick schematic diagrams of the uranium antimony tungstate anion of the present invention; f is the position of the {SbO3} unit in the compound; g is the dihedral angle between the [SbW9O 33 Sb(OH)] 7- units. {WO6}, blue-green octahedron; O, red sphere; Sb, blue sphere; W, blue-green sphere; U, yellow sphere.

[0055] The specific structure of the uranium antimony tungstate of the present invention is described as follows: The uranium antimony tungstate of the present invention contains a dimeric [(UO2)2(H2O)2(SbW9O 33 )2(Sb(OH))2] 10- anion, ten ammonium ions, and 31 lattice water molecules. The X-ray single crystal diffraction analysis results show that the [(UO2)2(H2O)2(SbW9O 33 )2(Sb(OH))2] 10- anion is composed of two [SbW9O 33 Sb(OH)]​7- The unit is connected by sharing UO2 2+ cations, and two uranyl ions are adjacent in position. [SbW9O 33 Sb(OH)] 7- The anion can be regarded as composed of {SbO3} units bonded to a three - vacancy Keggin - type [SbW9O 33 9- unit through two μ2 - O atoms. Among them, uranium has a pentagonal bipyramid configuration with seven - coordination, and the acyl O groups of the UO2 2+ cation are arranged approximately perpendicular to each other. One oxygen atom in the equatorial position comes from the coordinated water molecule, and the remaining 4 oxygen atoms come from the terminal oxygen atoms of two [SbW9O 33 9- units respectively. [(UO2)2(H2O)2(SbW9O 33 )2(Sb(OH))2] 10- The anion as a whole forms a structure similar to a bow - tie shape. In the [SbW9O 33 Sb(OH)] 7- unit, the Sb atom has a trigonal pyramid geometric configuration with three - coordination. [(UO2)2(H2O)2(SbW9O 33 )2(Sb(OH))2] 10- The four Sb atoms in the anion are arranged in a trapezoid, and the distance between Sb1 - Sb4 is The distance between Sb2 - Sb3 is There is an angle of 43.357° between two [SbW9O 33 Sb(OH)] 7- units; the bond lengths of the U = O bonds in the UO2 2+ cation are in the range of , the bond angles of O = U = O are 176.471° and 175.697°, and the bond angle range of O = U - O is 85.72° - 96.193°.

[0056] Bond - valence calculations (see Brown ID, et.al, 1985, B41, 244 - 247.) show that the valence of W and U atoms in the uranium - antimony - tungstate of the present invention is +6, and the valence of the Sb atom is +3. Calculating all oxygen atoms, it is found that the valences of O27 and O63 are - 0.28 and - 0.31 respectively, which are coordinated water molecules; the valences of O60 and O68 are - 0.99 and - 0.93 respectively, which are hydroxyl groups; the remaining oxygen atoms have a valence of - 2.

[0057] (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O has the following unit - cell parameters:​​ α = 89.1980(10)°, β = 89.5610(10)°, γ = 83.9440(10)°.

[0058] Figure 3 The infrared spectra (a) and X-ray powder diffraction patterns (b) before and after the proton conductivity test of the uranium-containing antimony tungstate prepared in Example 1 were prepared. By comparison, it was found that the infrared spectra and X-ray powder diffraction patterns of the uranium-containing antimony tungstate of the present invention did not change before and after the test, indicating that the structure did not change after the test.

[0059] Application Example

[0060] The uranium-containing antimony tungstate prepared in Example 1 was used as a proton conductive material, and its performance was tested as follows:

[0061] 10 mg of the uranium-containing antimony tungstate of the present invention was selected and placed in a mold. Under a pressure of 5 MPa, it was pressed into a thin sheet with a diameter of 3 mm and a thickness of 0.104 mm. The Nyquist diagrams at different temperatures and humidities were measured in the range of 0.1 V voltage and 10 MHz - 1 Hz. According to the conductivity formula σ = L / (RS), the conductivities under different conditions were calculated, where σ is the proton conductivity (S cm -1 ); L is the thickness of the thin sheet (cm); R is the resistance (Ω); S is the area of the thin sheet (cm 2 ). The activation energy at different temperatures under 85% humidity was calculated according to the Arrhenius equation ln(σ T ) = lnσ - Ea / (KT), where T is the measurement temperature (K), and K is the Boltzmann constant (eV K -1 ).

[0062] The proton conductive properties of the uranium-containing antimony tungstate of the present invention were tested at 25 °C and 45% - 85% humidity, and the relevant Niquist curves were plotted (see Figure a in Figure 2 ). According to the formula, it was calculated that the conductivity of the uranium-containing antimony tungstate of the present invention was 6.36×10 -3 S cm -1 under the conditions of 25 °C and 45% humidity. As the humidity increased, the conductivity also increased, and the conductivity reached 8.69×10 -3 S cm -1 at 85% humidity (see Figure b in Figure 2 ). At 85% humidity, the effect of temperature on the proton conductive properties was studied, and the relevant Niquist curves are shown in Figure c in Figure 2 . According to the formula, it was calculated that as the temperature increased from 25 °C to 85 °C, its conductivity increased from 8.69×10 -3 S cm -1Increased to 8.68×10 -2 S cm -1 . Under the conditions of 85% humidity and 25°C to 85°C, linear fitting was performed according to the Arrhenius equation (see Figure 2 Figure d therein), and the activation energy Ea was obtained as 0.314 eV (less than 0.4 eV), indicating that the Grotthuss mechanism of proton conduction dominates, and protons are transferred through the hydrogen bond network jump. Therefore, the uranium antimonate tungstate of the present invention can be applied to proton conductive materials.

[0063] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A uranium-containing antimonotungstate, characterized in that, The chemical formula is (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O, belonging to the triclinic system, with the space group P-1 and the unit cell parameters as follows: α = 89.1980(10)°, β = 89.5610(10)°, γ = 83.9440(10)°, Z = 1.

2. The uranium-containing antimonate tungstate according to claim 1, wherein The uranium-containing antimony tungstate (NH4) 10 [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2]·31H2O contains 10 ammonium ions, one [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2] 10- polyoxyanion and 31 crystal water molecules.

3. The uranium-containing antimonotungstate according to claim 2, wherein The [(UO2)2(H2O)2(SbW9O 33 )2(SbOH)2] 10- The polyanion contains two uranyl ions and two [(SbW9O 33 )(SbOH)] 7- units.

4. The preparation method of the uranium-containing antimony tungstate according to claim 3, characterized in that, The steps are as follows: Dissolve (NH4) 18 [NaSb9W 21 O 86 ·24H2O in distilled water, then add Na2WO4·2H2O, and adjust the pH to 4.3 - 5.0 with acetic acid solution. Subsequently, add a solution of UO2(NO3)2·6H2O dropwise and adjust the pH to 3.0 - 3.8 with hydrochloric acid solution. Then add ammonium chloride, and finally heat for reaction. After the reaction solution is cooled to room temperature, filter it, and let the clear filtrate stand and volatilize at room temperature to obtain uranium antimony tungstate crystals.

5. The preparation method of the uranium-containing antimonate tungstate according to claim 4, characterized in that, The concentration of the acetic acid solution is 6 mol / L.

6. The preparation method of the uranium-containing antimonate tungstate according to claim 5, characterized in that, The concentration of the hydrochloric acid solution is 3 mol / L.

7. The preparation method of the uranium-containing antimonate tungstate according to claim 6, wherein, The UO2(NO3)2·6H2O solution is an aqueous solution of UO2(NO3)2·6H2O with a concentration of 1 mol / L.

8. The preparation method of the uranium-containing antimonate tungstate according to claim 7, characterized in that, (NH4) in the reaction solution 18 [NaSb9W 21 O 86 ·24H2O, Na2WO4·2H2O, UO2(NO3)2·6H2O and NH4Cl are in a molar ratio of 1:4:(3 - 5):

110.

9. The preparation method of the uranium-containing antimonotungstate according to any one of claims 4-8, characterized in that, The temperature of the reaction is 50 - 60 °C, the time is 0.5 - 2 h; the static volatilization time is 10 - 20 days.

10. Use of the uranium antimonate tungstate according to any one of claims 1 - 3 as a proton conductive material.

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