Preparation method and application of an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst

Abstract

This invention provides a method for preparing and applying an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten-antimonate visible light photocatalyst. Belonging to the field of catalyst technology, the method for preparing an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten-antimonate visible light photocatalyst includes the following steps: sodium tungstate dihydrate, ammonium chloride, tetramethylammonium bromide, antimony trichloride, and uranyl nitrate hexahydrate are sequentially added to a 100 mL beaker; 30-100 mL of deionized water is added to the beaker, and then... (The sentence is incomplete and requires further context to translate accurately.) ‑1 Adjust the pH of the solution with HCl solution to pH 2-5; after stirring the reaction solution in step S2 evenly, place it in a water bath and heat it at 60-100℃ for 3 hours; after taking out the reaction solution in step S3 and cooling it to room temperature, filter it and evaporate the filtrate in the open at room temperature.

Description

Technical Field

[0001] This invention belongs to the field of catalyst technology, specifically relating to a method for preparing and applying a sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst modified with inorganic-organic mixed ammonium. Background Technology

[0002] Fluorinated organic compounds (FOCs) have wide applications in industrial production and consumer goods. Among them, perfluorooctane sulfonate (PFOS) possesses both oleophobic and hydrophobic properties, making it widely used in the production of stain-resistant agents for textiles, leather goods, furniture, and carpets. Due to its high chemical stability, it is used as an intermediate in the production of coatings, foam fire extinguishers, floor polishes, pesticides, and termite control agents. Furthermore, it is used in paint additives, adhesives, pharmaceutical products, flame retardants, petroleum and mining products, and insecticides. Currently, 96 different FOCs can release PFOS through degradation in the environment; these substances are called PFOS-related substances. Contrary to the typical behavior of many persistent organic pollutants, FOCs do not accumulate in adipose tissue because they are both hydrophobic and lipophobic. Conversely, PFOS is attached to proteins in the blood and liver, and research results indicate that PFOS and its derivatives are difficult for organisms to excrete through inhalation and intake via drinking water and food, and ultimately accumulate in the blood, liver, kidneys, and brain of the human body and other organisms.

[0003] PFOS is one of the most recalcitrant organic pollutants, and its degradation methods include physical separation, chemical degradation, biodegradation, and others such as molecular imprinting, high and low temperature plasma methods. Physical separation methods cannot completely degrade PFOS, the adsorbent cannot be reused, and the cost is high. Chemical degradation methods suffer from harsh conditions and high costs. Biodegradation has been less studied, but it also suffers from long processing times, sensitivity of microorganisms to environmental changes, and the influence of microorganisms on processing efficiency. Therefore, it is essential to develop a catalyst that achieves rapid, complete, and reusable degradation of PFOS. Summary of the Invention

[0004] Based on the above-mentioned technical problems, the present invention provides a method for preparing and applying an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst.

[0005] The specific technical solution is as follows:

[0006] A sandwich-type dinuclear uranium-tungsten antimonate visible light photocatalyst modified with inorganic-organic mixed ammonium has the structural formula (NH4). 12 [N(CH3)4]2{[UO2(H2O)]2[SbW9O 33 ] }2·17H2O, chemical formula C8H 110 N 14 O 89 Sb2W 18 U2 belongs to the triclinic crystal system and has a space group of . P -1, the unit cell parameters are: a =13.0578(6) Å, b =18.8944(8) Å, c =20.6558(9) Å, α =87.397(2)º, b =80.522(2)º, γ =82.395(2)º, V =4980.9(4) Å 3 , Z =2;

[0007] The structural formula contains two monohydrated uranyl ions [UO2(H2O)]. 2+ Sandwich replaces two [SbW9O] 33 ] 9- Ions form a stable dimer {[UO2(H2O)]2[SbW9O]2} 33 ]} 14- The counteracting cations are two tetramethylammonium cations and 12 ammonium ions, for a total of 17 water molecules of crystallization.

[0008] A method for preparing an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst includes the following steps:

[0009] S1: Add sodium tungstate dihydrate, ammonium chloride, tetramethylammonium bromide, antimony trichloride and uranyl nitrate hexahydrate sequentially to a 100 mL beaker;

[0010] S2: Add 30-100 mL of deionized water to the beaker, and use 6 mol·L⁻¹ water. -1 HCl solution is used to adjust the pH of the solution to a value of 2-5.

[0011] S3: After stirring the reaction solution in step S2 evenly, place it in a water bath and heat it at 60-100℃ for 3 hours.

[0012] S4: After the reaction solution in step S3 is taken out and cooled to room temperature, it is filtered, and the filtrate is evaporated in the open at room temperature;

[0013] S5: After waiting for 15 days, yellow strip-shaped crystals precipitate out. After filtration, the crystals are washed with deionized water and anhydrous ethanol, and then naturally dried to obtain the target uranium tungstate antimonate.

[0014] In the above technical solution, in step S1, the amounts of sodium tungstate dihydrate, ammonium chloride, tetramethylammonium bromide, antimony trichloride, and uranyl nitrate hexahydrate are 20 mmol, 20 mmol, 2 mmol, 2 mmol, and 2 mmol, respectively.

[0015] In the above technical solution, in step S2, the pH of the solution is 3.

[0016] In the above technical solution, in step S3, the temperature of the water bath is 85°C.

[0017] An inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst for visible light catalytic degradation of perfluorooctane sulfonic acid.

[0018] The present invention discloses a method for preparing and applying an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst. Compared with the prior art, the advantages are as follows:

[0019] This invention provides a method for preparing a sandwich-type dinuclear uranyl tungsten antimonate visible light photocatalyst modified with inorganic-organic mixed ammonium. The method employs a one-step synthesis of uranyl polyacid salt visible light photocatalysts at room temperature and aqueous solution. This method is simple, low-cost, and the resulting uranyl polyacid salt visible light photocatalyst achieves a degradation rate of 90.5% in 5 minutes and 96.3% in 30 minutes when used to degrade perfluorooctane sulfonic acid. Furthermore, it exhibits good stability, mild degradation conditions, rapid degradation, high degradation rate, and the ability to be reused while preventing secondary pollution. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light catalyst of the present invention, wherein all ammonium ions are not hydrogenated, while the others such as coordinated water, water of crystallization and tetramethylammonium cation are hydrogenated;

[0021] Figure 2 The infrared spectrum of the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst of the present invention is shown.

[0022] Figure 3 The PXRD pattern of the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst of the present invention is obtained through theoretical simulation and experimental measurement.

[0023] Figure 4 This is a schematic diagram showing the relationship between the degradation rate and time of the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light catalyst for the photocatalytic degradation of perfluorooctane sulfonic acid according to the present invention.

[0024] Figure 5This is a graph showing the relationship between the number of cycles and the degradation rate of the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst of the present invention.

[0025] Figure 6 The powder diffraction pattern of the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light catalyst of the present invention is shown in theoretical simulations, in freshly prepared samples, and in the catalyst recovered after 10 cycles of visible light catalytic degradation of PFOS. Detailed Implementation

[0026] The following are specific implementation cases and appendices. Figure 1-6 The present invention will be further described, but the present invention is not limited to these embodiments. Example 1:

[0027] A sandwich-type dinuclear uranium-tungsten antimonate visible light photocatalyst modified with inorganic-organic mixed ammonium has the structural formula (NH4). 12 [N(CH3)4]2{[UO2(H2O)]2[SbW9O 33 ]2}·17H2O, chemical formula C8H 110 N 14 O 89 Sb2W 18 U2 belongs to the triclinic crystal system and has a space group of . P -1, the unit cell parameters are: a =13.0578(6) Å, b =18.8944(8) Å, c =20.6558(9) Å, α =87.397(2)º, b =80.522(2)º, γ =82.395(2)º, V =4980.9(4) Å 3 , Z =2;

[0028] The structural formula contains two monohydrated uranyl ions [UO2(H2O)]. 2+ Sandwich replaces two [SbW9O] 33 ] 9- Ions form a stable dimer {[UO2(H2O)]2[SbW9O]2} 33 ]} 14- The counteracting cations are two tetramethylammonium cations and 12 ammonium ions, for a total of 17 water molecules of crystallization.

[0029] A method for preparing an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst includes the following steps:

[0030] S1: Add sodium tungstate dihydrate, ammonium chloride, tetramethylammonium bromide, antimony trichloride and uranyl nitrate hexahydrate sequentially to a 100 mL beaker;

[0031] S2: Add 30-100 mL of deionized water to the beaker, and use 6 mol·L⁻¹ water. -1 HCl solution is used to adjust the pH of the solution to a value of 2-5.

[0032] S3: After stirring the reaction solution in step S2 evenly, place it in a water bath and heat it at 60-100℃ for 3 hours.

[0033] S4: After the reaction solution in step S3 is taken out and cooled to room temperature, it is filtered, and the filtrate is evaporated in the open at room temperature;

[0034] S5: After waiting for 15 days, yellow strip-shaped crystals precipitate out. After filtration, the crystals are washed with deionized water and anhydrous ethanol, and then naturally dried to obtain the target uranium tungstate antimonate.

[0035] In an embodiment of the present invention, in step S1, the amounts of sodium tungstate dihydrate, ammonium chloride, tetramethylammonium bromide, antimony trichloride, and uranyl nitrate hexahydrate are 20 mmol, 20 mmol, 2 mmol, 2 mmol, and 2 mmol, respectively.

[0036] In an embodiment of the present invention, in step S2, the pH of the solution is 3.

[0037] In an embodiment of the present invention, in step S3, the temperature of the water bath is 85°C. Example 2:

[0038] An inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst for visible light catalytic degradation of perfluorooctane sulfonic acid.

[0039] In an embodiment of the present invention, the application of an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten antimonate visible light photocatalyst in the degradation of perfluorooctane sulfonic acid includes the following steps: First, the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten antimonate visible light photocatalyst is ground into powder for 10 minutes; 10 mg of the yellow powder is dissolved in 20 mL of a 10 mg·L⁻¹ solution. -1 In an aqueous solution of PFOS, the solution was placed in a photocatalytic reaction apparatus with a stirrer turned on and illuminated by a 300W LED lamp (simulating a visible light source). Within 5 minutes, 95.8% of the perfluorooctane sulfonic acid in the aqueous solution was degraded, and after 30 minutes, the degradation rate reached 99.5%, thus yielding the desired product. Figure 4 The photocatalytic degradation curve is shown.

[0040] In this embodiment, control group 1 and control group 2 were set up respectively. Control group 1 was a blank control group, without the addition of any catalyst, but under LED light irradiation, at which time perfluorooctane sulfonic acid hardly degraded; control group 2 was prepared by first stabilizing the perfluorooctane sulfonic acid test solution in a dark environment, and then adding the catalyst of the present invention, while still maintaining a dark environment. At this time, under the condition of no visible light participation, the activity of the catalyst was very low, and the degradation rate was only 12.2%.

[0041] Specifically, the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten-antimonate visible light photocatalyst can be recovered through water precipitation, and its degradation rate for recycling 1 to 10 times is as follows: Figure 5 As shown.

[0042] like Figure 5 As shown, the inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten antimonate visible light photocatalyst has a degradation rate of 95.2% after 10 cycles, indicating that its catalytic activity is well maintained. This inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten antimonate visible light photocatalyst can be reused multiple times while maintaining good catalytic performance.

[0043] like Figure 6 As shown, the powder diffraction peaks under the three conditions overlap very well, indicating that this visible light catalyst has excellent stability and will not produce secondary pollution.

[0044] In the description of this invention, the term "a plurality of" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances.

[0045] In the description of this invention, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this invention, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0046] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst modified with inorganic-organic mixed ammonium, characterized in that, Its structural formula is The chemical formula is It belongs to the triclinic crystal system and has a space group of The unit cell parameters are: , , , ; The structural formula contains two monohydrated uranyl ions. Sandwich replaces two Ions, forming stable dimers The counteracting cations are two tetramethylammonium cations and 12 ammonium ions, for a total of 17 water molecules of crystallization.

2. The method for preparing an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten-antimonate visible light photocatalyst according to claim 1, characterized in that, Includes the following steps: S1: Add sodium tungstate dihydrate, ammonium chloride, tetramethylammonium bromide, antimony trichloride and uranyl nitrate hexahydrate sequentially to a 100 mL beaker; S2: Add 30-100 mL of deionized water to the beaker, and use 6 mol·L⁻¹ water. -1 HCl solution is used to adjust the pH of the solution to a value of 2-5. S3: After stirring the reaction solution in step S2 evenly, place it in a water bath and heat it at 60-100℃ for 3 hours. S4: After the reaction solution in step S3 is taken out and cooled to room temperature, it is filtered, and the filtrate is evaporated in the open at room temperature; S5: After waiting for 15 days, yellow strip-shaped crystals precipitate out. After filtration, the crystals are washed with deionized water and anhydrous ethanol, and then naturally dried to obtain the target uranium tungstate antimonate.

3. The method for preparing an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten-antimonate visible light photocatalyst according to claim 2, characterized in that, In step S1, the amounts of sodium tungstate dihydrate, ammonium chloride, tetramethylammonium bromide, antimony trichloride, and uranyl nitrate hexahydrate are 20 mmol, 20 mmol, 2 mmol, 2 mmol, and 2 mmol, respectively.

4. The method for preparing an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten-antimonate visible light photocatalyst according to claim 2, characterized in that, In step S2, the pH of the solution is 3.

5. The method for preparing an inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium-tungsten-antimonate visible light photocatalyst according to claim 2, characterized in that, In step S3, the temperature of the water bath is 85°C.

6. The inorganic-organic mixed ammonium modified sandwich-type dinuclear uranium tungsten antimonate visible light photocatalyst according to claim 1 is used for visible light catalytic degradation of perfluorooctane sulfonic acid.

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