Covalent organic framework materials containing amino-substituted benzothiophene sulfone and preparation method and application thereof

Abstract

The application discloses a covalent organic framework material containing amino-substituted benzothiophene sulfone and a preparation method and application thereof, belongs to the technical field of photocatalytic materials, and is characterized in that in mesitylene and 1,4-dioxane, a Schiff base reaction occurs between an aldehyde group and an amine group to form an imine bond, the stability and photoelectric catalytic performance of the material are improved, the covalent organic framework material containing amino-substituted benzothiophene sulfone has high crystallinity and excellent stable porosity, and the photocatalytic activity and stability are significantly improved. The Schiff base reaction between the aldehyde group and the amine group forms a stable imine bond multi-component COF, the unique electronic structure and energy band regulation capability of the imine bond multi-component COF exhibit photocatalytic activity and stability superior to those of a traditional two-component COF material, the unique sulfone group structure, 1,3,5-tri-(4-formyl-phenyl) triazine and 2,4,6-triformylphloroglucinol interaction improves the photo-induced charge separation efficiency and the performance of photocatalytic production of hydrogen peroxide.

Description

Technical Field

[0001] This invention relates to the field of photocatalytic materials technology, specifically to amino-substituted benzothiophene sulfone covalent organic framework materials, their preparation methods, and applications. Background Technology

[0002] Hydrogen peroxide is widely recognized as one of the most valuable commercial chemicals, with broad applications, particularly in wastewater treatment, medical disinfection, and chemical synthesis. It serves as a substrate for various reactions and plays a crucial role in organic synthesis. Hydrogen peroxide is typically produced using the anthraquinone process; however, this chemical method presents several challenges, with high energy consumption being particularly pronounced in industrial-scale operations, thus increasing the cost of hydrogen peroxide production.

[0003] Photocatalysis is a highly efficient, environmentally friendly, and mild solar-to-chemical energy conversion pathway, in which photocatalysts play a crucial role. With the increasing global demand for renewable energy, the development of photocatalysis technology is particularly important. The core principle of photocatalysis is to utilize the electron-hole pairs generated by the photocatalyst under light radiation to initiate a series of redox reactions, achieving the conversion or decomposition of target substances. Studies have shown that by optimizing the design of photocatalysts and improving the structure of photocatalytic systems, the production efficiency of hydrogen peroxide can be significantly improved. Furthermore, solar-driven photocatalysis technology plays a vital role in addressing the energy crisis and environmental problems. With the gradual depletion of fossil fuel resources and the increasing severity of environmental pollution, finding clean and renewable energy alternatives has become a paramount task.

[0004] Covalent organic frameworks (COFs) are a class of porous crystalline materials formed by strong covalent bonds connecting lightweight elements such as carbon, hydrogen, boron, oxygen, nitrogen, and silicon. Since their initial report in 2005, COFs have demonstrated significant application potential in numerous fields due to their unique structure and properties, particularly excelling in photocatalysis. Characterized by high specific surface area, tunable functional groups, and excellent photoelectric properties, COFs exhibit immense application value in photocatalysis. Through scientific structural design and functional modification, COFs can effectively improve the efficiency and selectivity of photocatalytic reactions, providing novel solutions for clean energy development, environmental pollution control (such as the degradation of organic pollutants), and green chemical synthesis. However, existing COF materials exhibit low yields in the photocatalytic production of hydrogen peroxide. For example, imine-linked COFs, such as TpPa-1, with a microporous structure accounting for over 80%, only achieve a hydrogen peroxide yield of 1200 μmol·h⁻¹ under simulated sunlight irradiation. -1 ·g -1This data is far below the efficiency standards required for industrial production. A COF based on benzidine, namely BPDA-COF, although possessing a mesoporous structure, suffers from a photocatalytic hydrogen peroxide production rate of only 1800 μmol·h⁻¹ due to the lack of effective catalytic active sites on the pore walls. -1 ·g -1 Similarly, it is difficult to meet actual production needs. Summary of the Invention

[0005] This invention provides a covalent organic framework material containing amino-substituted benzothiophene sulfone, its preparation method, and its application. It effectively solves the technical problem of low yield of hydrogen peroxide in photocatalytic production of existing covalent organic framework materials. This invention improves the performance of photocatalytic hydrogen peroxide production by increasing the photogenerated charge separation efficiency through the interaction between the three components: amino-substituted benzothiophene sulfone, 1,3,5-tris-(4-formyl-phenyl)triazine, and 2,4,6-triformyl-phloroglucinol.

[0006] The first objective of this invention is to provide a method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone, comprising the following steps:

[0007] Using 1,3,5-tris-(4-formyl-phenyl)triazine, amino-substituted benzothiophene sulfone, and 2,4,6-tricarboxymethyl phloroglucinol as raw materials, and mesitylene and 1,4-dioxane as solvents, a suspension was obtained by sonication. Acetic acid solution was added to the suspension, and three freeze-thaw cycles were performed. Under vacuum at 120℃~180℃, the aldehyde groups in 1,3,5-tris-(4-formyl-phenyl)triazine and 2,4,6-tricarboxymethyl phloroglucinol underwent a Schiff base reaction with the primary amine in the amino-substituted benzothiophene sulfone to obtain a covalent organic framework material containing amino-substituted benzothiophene sulfone.

[0008] In the above technical solution, the purpose of freezing, evacuation and thawing is to create a vacuum environment to completely remove gaseous impurities from the system, thereby facilitating the reaction and improving the crystallinity of the reaction product. The reason for using three freezing, evacuation and thawing cycles is that a single freezing-evacuation-thawing cycle is difficult to completely remove the gas, and multiple cycles will not significantly improve the degassing effect, but will instead increase the operation time and energy consumption. Moreover, repeated freezing and thawing will cause some raw materials to undergo side reactions prematurely due to drastic temperature changes, affecting the structural stability of the product. Therefore, three freezing, evacuation and thawing cycles are the best approach.

[0009] In a preferred embodiment, the molar ratio of 1,3,5-tris-(4-formyl-phenyl)triazine, amino-substituted benzothiophene sulfone, and 2,4,6-triformylphloroglucinol is 1:2.5~3.5:0.8~1.2.

[0010] In a preferred embodiment, the volume ratio of mesitylene to 1,4-dioxane is 1.8 to 2.2:3.

[0011] In a preferred embodiment, the molar ratio of 2,4,6-tricarboxymethyl phloroglucinol to acetic acid is 1:0.0024~0.0036.

[0012] In a preferred embodiment, the vacuum degree is 1×10⁻⁶. -3 Pa ~ 1×10 -1 Pa.

[0013] In a preferred embodiment, the Schiff base reaction time is 60h~84h.

[0014] In a preferred embodiment, after the Schiff base reaction is completed, the product is filtered to obtain a primary product. The primary product is then subjected to Soxhlet extraction with tetrahydrofuran and acetone, and vacuum dried at 50°C to 60°C to obtain a covalent organic framework material containing amino-substituted benzothiophene sulfone.

[0015] A second objective of this invention is to provide an amino-substituted benzothiophene sulfone covalent organic framework material, prepared by any of the methods described above.

[0016] A third objective of this invention is to provide an application of the above-mentioned amino-substituted benzothiophene sulfone covalent organic framework material in the photocatalytic production of hydrogen peroxide.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] This invention provides a method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone. In this invention, a Schiff base reaction is conducted in the unique solvent systems of mesitylene and 1,4-dioxane, where the aldehyde groups of 1,3,5-tris-(4-formyl-phenyl)triazine and 2,4,6-triformylphloroglucinol react with the primary amine in the amino-substituted benzothiophene sulfone. The nitrogen atom of the amine carries a lone pair of electrons, which attacks the positive potential of the carbonyl carbon atom in the aldehyde group, forming an intermediate α-hydroxyamine. Subsequently, a Schiff base structure is formed through a dehydration reaction. Highly crystalline materials cannot be obtained in other conventional solvent systems. Compared to other chemical bonds, the formation of the imine bond significantly improves the stability and photocatalytic and electrocatalytic performance of the material. The amino-substituted benzothiophene sulfone covalent organic framework material prepared by this invention exhibits high crystallinity and excellent stable porosity, thereby significantly improving photocatalytic activity and stability. A multi-component COF, formed by the Schiff base reaction of aldehyde and amine groups to form chemically stable imine bonds, exhibits superior photocatalytic activity and stability compared to traditional two-component COF materials due to its unique electronic structure and bandgap modulation capability. The unique sulfone structure, 1,3,5-tris-(4-formyl-phenyl)triazine, and 2,4,6-triformyl-phloroglucinol interact with each other, increasing the efficiency of photogenerated charge separation and effectively improving the photocatalytic production of hydrogen peroxide.

[0019] This invention prepared a covalent organic framework material containing amino-substituted benzothiophene sulfone, designated COF-830, via a solvothermal method. Its photocatalytic hydrogen peroxide production performance in pure aqueous solution without sacrificial agents or co-catalysts reached 2023 μmol·g⁻¹. -1 ·h -1 It is 1.57 times that of COF-816, a covalent organic framework material containing amino-substituted benzothiophene sulfone prepared from amino-substituted benzothiophene sulfone and 1,3,5-tris-(4-formyl-phenyl)triazine, which is one of the highest yields among existing photocatalysts for producing hydrogen peroxide. Attached Figure Description

[0020] Figure 1 This is a structural diagram of COF-830 prepared in Example 1 of the present invention.

[0021] Figure 2 This is a structural diagram of COF-816 prepared in Comparative Example 1 of the present invention.

[0022] Figure 3 The XRD pattern and simulated pattern of COF-830 prepared in Example 1 of this invention are shown.

[0023] Figure 4 The XRD pattern and simulated pattern of COF-816 prepared in Comparative Example 1 of this invention are shown.

[0024] Figure 5 The images show the FT-TR spectra of each raw material and the prepared COF-830 in Example 1 of this invention, where 1 is COF-830, 2 is 1,3,5-tris-(4-formyl-phenyl)triazine, 3 is amino-substituted benzothiophene sulfone, and 4 is 2,4,6-triformylphloroglucinol.

[0025] Figure 6 The images show the FT-TR spectra of each raw material and the prepared COF-816 in Comparative Example 1 of this invention, where 1 is COF-816, 2 is amino-substituted benzothiophene sulfone, and 3 is 1,3,5-tris-(4-formyl-phenyl)triazine.

[0026] Figure 7 This is a SEM image of COF-830 prepared in Example 1 of the present invention.

[0027] Figure 8 This is a SEM image of COF-816 prepared in Comparative Example 1 of this invention.

[0028] Figure 9 The hydrogen peroxide yield spectra of COF-830 prepared in Example 1 and COF-816 prepared in Comparative Example 1 as a function of time are shown. Detailed Implementation

[0029] To enable those skilled in the art to better understand and implement the technical solutions of this invention, the invention will be further described below with reference to specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the invention. Unless otherwise specified, the following test methods and detection methods are conventional methods; unless otherwise specified, the reagents and raw materials are commercially available.

[0030] In view of the technical problem of low yield of hydrogen peroxide production by photocatalysis of existing covalent organic framework materials mentioned in the background of this invention, this invention provides a covalent organic framework material containing amino-substituted benzothiophene sulfone, its preparation method and application.

[0031] The technical solution of the present invention will be analyzed and described in detail below.

[0032] This invention first provides a method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone, comprising the following steps:

[0033] Using 1,3,5-tris-(4-formyl-phenyl)triazine, amino-substituted benzothiophene sulfone, and 2,4,6-triformyl-resorcinol as raw materials, and mesitylene and 1,4-dioxane as solvents, a suspension was obtained by sonication. Acetic acid solution was added to the suspension, and three freeze-thaw cycles were performed at a vacuum of 1×10⁻⁶. -3 Pa ~ 1×10 -1Under vacuum of Pa, at 120℃~180℃, the aldehyde groups in 1,3,5-tris-(4-formyl-phenyl)triazine and 2,4,6-triformyl-resorcinol react with the primary amine in amino-substituted benzothiophene sulfone in a Schiff base reaction for 60h~84h to obtain a covalent organic framework material containing amino-substituted benzothiophene sulfone.

[0034] The amino-substituted benzothiophene sulfone covalent organic framework material prepared using the above-mentioned technical solution exhibits high crystallinity and excellent stable porosity, thereby significantly improving photocatalytic activity and stability. The aldehyde and amine groups undergo a Schiff base reaction to form a chemically stable imine bond multi-component COF. With its unique electronic structure and band structure modulation ability, it demonstrates superior photocatalytic activity and stability compared to traditional two-component COF materials. The unique sulfone structure, 1,3,5-tris-(4-formyl-phenyl)triazine, and 2,4,6-triformyl-phloroglucinol interact among the three components, increasing the photogenerated charge separation efficiency and effectively improving the photocatalytic production of hydrogen peroxide.

[0035] The purpose of using freezing, evacuation, and thawing in the above technical solution is to create a vacuum environment to thoroughly remove gaseous impurities from the system, thereby facilitating the reaction and improving the crystallinity of the reaction product. The reason for using three freezing, evacuation, and thawing cycles is that a single freezing-evacuation-thawing cycle is insufficient to completely remove the gas, while multiple cycles do not significantly improve the degassing effect but instead increase operation time and energy consumption. Furthermore, repeated freezing and thawing can cause some raw materials to undergo side reactions prematurely due to drastic temperature changes, affecting the structural stability of the product. Therefore, using three freezing, evacuation, and thawing cycles is the optimal approach.

[0036] To further improve the stability and photocatalytic and electrocatalytic performance of the material, the molar ratio of 1,3,5-tris-(4-formyl-phenyl)triazine, amino-substituted benzothiophene sulfone, and 2,4,6-triformylphloroglucinol is 1:2.5~3.5:0.8~1.2. The volume ratio of mesitylene to 1,4-dioxane is 1.8~2.2:3. The molar ratio of 2,4,6-triformylphloroglucinol to acetic acid solution is 1:0.0024~0.0036. The concentration of the acetic acid solution is 3 mol / L, and the volume ratio of 2,4,6-triformylphloroglucinol to acetic acid solution is 1 mol:0.8 mL~1.2 mL.

[0037] To obtain a covalent organic framework material containing amino-substituted benzothiophene sulfone with good yield and purity, after the Schiff base reaction is completed, the mixture is filtered to obtain a primary product. The primary product is then extracted using tetrahydrofuran and acetone using a Soxhlet extraction method and dried under vacuum at 50°C to 60°C to obtain a covalent organic framework material containing amino-substituted benzothiophene sulfone.

[0038] The technical effects of the present invention will be described below with reference to specific embodiments and comparative examples.

[0039] Example 1

[0040] A method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone includes the following steps:

[0041] A mixture of 16.5 mg of 1,3,5-tris-(4-formyl-phenyl)triazine, 32.9 mg of amino-substituted benzothiophene sulfone, and 8.4 mg of 2,4,6-triformyl-resorcinol (molar ratio 1:3:1) was added to a 15 mL Piezorx tube containing a mixed solvent system of mesitylene and 1,4-dioxane (volume ratio 2:3). The mixture was sonicated for 10 min to ensure thorough dispersion and obtain a homogeneous suspension. Then, 1 mL of a 3 mol / L acetic acid solution was added to the suspension, and the solvent was rapidly frozen into a solid using a liquid nitrogen bath. The frozen solvent was connected to a vacuum system, and the stopcock of the container was closed. A high-vacuum pump was used to evacuate the container for 3 minutes to remove gases and volatile substances from the solvent. The vacuum pump was then turned off, and the container was slowly heated to allow the solvent to gradually thaw under vacuum. This freezing-evacuation-thawing process was repeated three times to obtain a pressure of 1 × 10⁻⁶. - 3 The reaction was carried out in a vacuum-sealed environment at 120°C for 72 hours. After filtration, the initial product was obtained. The initial product was then subjected to Soxhlet extraction with tetrahydrofuran and acetone. Finally, the product was dried under vacuum at 60°C using a watch glass to obtain the final brownish-red product, namely the covalent organic framework material containing amino-substituted benzothiophene sulfone, denoted as COF-830, with a yield of 98%. Its structure is as follows. Figure 1 As shown.

[0042] Example 2

[0043] A method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone includes the following steps:

[0044] A mixture of 16.5 mg of 1,3,5-tris-(4-formyl-phenyl)triazine, 27.4 mg of amino-substituted benzothiophene sulfone, and 6.7 mg of 2,4,6-tricarboxymethyl phloroglucinol (molar ratio 1:2.5:0.8) was added to a 15 mL Piezerx tube containing a mixed solvent system of trimethylbenzene and 1,4-dioxane (volume ratio 2:3). The mixture was sonicated for 10 min to achieve thorough dispersion and obtain a homogeneous suspension. Then, 1 mL of a 3 mol / L acetic acid solution was added to the suspension, and the solvent was rapidly frozen into a solid using a liquid nitrogen bath. The frozen solvent was connected to a vacuum system, and the stopcock of the container was closed. A high-vacuum pump was used to evacuate the container for 3 minutes to remove gases and volatile substances from the solvent. The vacuum pump was then turned off, and the container was slowly heated to gradually thaw the solvent under vacuum. This freezing-evacuation-thawing process was repeated three times to obtain a pressure of 1 × 10⁻⁶. -3 The reaction was carried out in a vacuum-sealed environment at 120°C for 72 h. After filtration, the initial product was obtained. The initial product was extracted by Soxhlet extraction with tetrahydrofuran and acetone. Finally, the product was dried under vacuum at 60°C using a watch glass to obtain 63.7 mg of the final brownish-red product, which is a covalent organic framework material containing amino-substituted benzothiophene sulfone with a yield of 98%, denoted as COF-830.

[0045] Example 3

[0046] A method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone includes the following steps:

[0047] A mixture of 16.5 mg of 1,3,5-tris-(4-formyl-phenyl)triazine, 38.4 mg of amino-substituted benzothiophene sulfone, and 10.1 mg of 2,4,6-tricarboxymethyl phloroglucinol (molar ratio 1:3.5:1.2) was added to a 15 mL Piezorx tube containing a mixed solvent system of trimethylbenzene and 1,4-dioxane (volume ratio 2:3). The mixture was sonicated for 10 min to ensure thorough dispersion and obtain a homogeneous suspension. Then, 1 mL of a 3 mol / L acetic acid solution was added to the suspension, and the solvent was rapidly frozen into a solid using a liquid nitrogen bath. The frozen solvent was connected to a vacuum system, and the stopcock of the container was closed. A high-vacuum pump was used to evacuate the container for 3 minutes to remove gases and volatile substances from the solvent. The vacuum pump was then turned off, and the container was slowly heated to allow the solvent to gradually thaw under vacuum. This freezing-evacuation-thawing process was repeated three times to obtain a pressure of 1 × 10⁻⁶. -3The reaction was carried out in a vacuum-sealed environment at 120°C for 72 h, followed by filtration to obtain the initial product. The initial product was then subjected to Soxhlet extraction with tetrahydrofuran and acetone, and finally dried under vacuum at 60°C using a watch glass to obtain 63.7 mg of the final brownish-red product, which is a covalent organic framework material containing amino-substituted benzothiophene sulfone with a yield of 98%, denoted as COF-830.

[0048] Example 4

[0049] A method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone includes the following steps:

[0050] A mixture of 16.5 mg of 1,3,5-tris-(4-formyl-phenyl)triazine, 27.4 mg of amino-substituted benzothiophene sulfone, and 8.4 mg of 2,4,6-tricarboxymethyl phloroglucinol (in a molar ratio of 1:2.5:1) was added to a 15 mL Piezorx tube containing a mixed solvent system of trimethylbenzene and 1,4-dioxane (in a volume ratio of 2:3). The mixture was sonicated for 10 min to ensure thorough dispersion and obtain a homogeneous suspension. Then, 1 mL of a 3 mol / L acetic acid solution was added to the suspension, and the solvent was rapidly frozen into a solid using a liquid nitrogen bath. The frozen solvent was connected to a vacuum system, and the stopcock of the container was closed. A high-vacuum pump was used to evacuate the container for 3 minutes to remove gases and volatile substances from the solvent. The vacuum pump was then turned off, and the container was slowly heated to allow the solvent to thaw gradually under vacuum. This freezing-evacuation-thawing process was repeated three times to obtain a pressure of 1 × 10⁻⁶. -3 The reaction was carried out in a vacuum-sealed environment at 120°C for 72 h, followed by filtration to obtain the initial product. The initial product was then subjected to Soxhlet extraction with tetrahydrofuran and acetone, and finally dried under vacuum at 60°C using a watch glass to obtain 63.7 mg of the final brownish-red product, which is a covalent organic framework material containing amino-substituted benzothiophene sulfone with a yield of 98%, denoted as COF-830.

[0051] To further illustrate the technical effects of the present invention, comparative examples are also provided, as follows:

[0052] Comparative Example 1

[0053] The difference from Example 1 is that 2,4,6-tricarboxymethyl phloroglucinol is not added.

[0054] A method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone includes the following steps:

[0055] A mixture of 16.5 mg of 1,3,5-tris-(4-formyl-phenyl)triazine and 32.9 mg of amino-substituted benzothiophene sulfone was added to a 15 mL Piezerx tube containing a 2:3 volume ratio of trimethylolpropene and 1,4-dioxane. The mixture was sonicated for 10 min to ensure complete dispersion, resulting in a homogeneous suspension. Then, 1 mL of a 3 mol / L acetic acid solution was added to the suspension, and the solvent was rapidly frozen into a solid using a liquid nitrogen bath. The frozen solvent was connected to a vacuum system, and the stopcock of the container was closed. A high-vacuum pump was used to evacuate the container for 3 minutes to remove gases and volatile substances from the solvent. The vacuum pump was then turned off, and the container was slowly heated to allow the solvent to gradually thaw under vacuum. This freezing-evacuation-thawing process was repeated three times to obtain a pressure of 1 × 10⁻⁶. -3 The reaction was carried out in a vacuum-sealed environment at 120°C for 72 hours. After filtration, the initial product was obtained. The initial product was then subjected to Soxhlet extraction with tetrahydrofuran and acetone. Finally, the product was dried under vacuum at 60°C using a watch glass to obtain 30.8 mg of the final bright yellow product, which is a covalent organic framework material containing amino-substituted benzothiophene sulfone with a yield of 56%, denoted as COF-816. Its structure is as follows. Figure 2 As shown.

[0056] The photocatalytic production of hydrogen peroxide was carried out using the covalent organic framework material containing amino-substituted benzothiophene sulfone prepared in the above examples and Comparative Example 1, as detailed below.

[0057] By preparing aqueous solutions of H2O2 with different known concentrations and reacting them with potassium iodide and potassium hydrogen phthalate, a mixed solution was obtained. The absorbance of the mixed solution at 350 nm was detected using a UV-Vis spectrophotometer. A standard curve was obtained by fitting the concentration and absorbance.

[0058] The specific method for detecting hydrogen peroxide in this invention is as follows: Take a certain amount of potassium iodide solution and potassium hydrogen phthalate (C8H5KO4 solution), add 1 mL of the solution obtained after photocatalytic reaction, store in the dark for 30 min, and then react with H2O2 under acidic conditions. - It will become I3 - That is, H2O2 + 3I - +2H + →I3 - The photocatalytic reaction produces H₂O, which exhibits a strong absorption peak at 350 nm using a UV-Vis spectrophotometer, and its absorbance value is also obtained. The amount of H₂O₂ produced during the photocatalytic reaction is calculated using a standard curve.

[0059] The testing procedure was as follows: Samples of amino-substituted benzothiophene sulfone covalent organic framework materials prepared in the examples and comparative examples were pretreated. The samples were dispersed in water, sonicated for a period of time, then centrifuged and freeze-dried. 5 mg of the freeze-dried sample was dispersed in 50 mL of deionized water and sonicated for 30 min until uniformly dispersed. The dispersion was then injected into a gas-liquid reactor, and air was degassed using oxygen bubbling for 20 min. The mixture was stirred in the dark for 30 min to achieve absorption and equilibrium of the analytical results. The reaction mixture was irradiated with a 300 W xenon lamp equipped with a 420 nm cutoff filter. The entire photoreaction process used a stirrer and circulating water, and the reaction temperature was controlled at 25 °C. Every 10 minutes, 1 mL of the reaction solution was taken out, centrifuged, filtered to remove the photocatalyst, and then 1 mL of the filtrate was used for a colorimetric reaction to measure the absorbance. The absorbance was then substituted into a standard curve to obtain the hydrogen peroxide production rate. The amino-substituted benzothiophene sulfone covalent organic framework material prepared in Example 1 of this invention exhibited the highest photocatalytic hydrogen peroxide production rate, which was 2023 μmol·g. -1 ·h -1 .

[0060] The morphology and properties of the amino-substituted benzothiophene sulfone covalent organic framework material prepared in the embodiments of the present invention were characterized and tested, and the results are as follows.

[0061] Figure 3 and Figure 4 The XRD patterns are those of COF-830 prepared in Example 1 and COF-816 prepared in Comparative Example 1 of this invention. Figure 3 and Figure 4 The numbers 1 and 1 represent the X-ray diffraction patterns of COF-830 and COF-816, respectively. Figure 3 and Figure 4 Figure 2 shows the peak positions of the two COFs simulated using the materials studio. As shown in the figure, the peak positions of COF-830 and COF-816 are consistent with those simulated using the materials studio, proving the successful preparation of COF-830 and COF-816.

[0062] Figure 5 and Figure 6 The figures show the FT-IR spectra of COF-830 prepared in Example 1 and COF-816 prepared in Comparative Example 1, respectively. The FT-IR spectra of COF-830 and COF-816 at 1600 cm⁻¹ are shown in the figure. -1 The presence of a strong absorption peak nearby indicates that the monomer underwent a Schiff base reaction, forming a C=N bond. Compared to amino-substituted benzothiophene sulfone, it exhibits a higher absorption peak at 3360 cm⁻¹. -1 The disappearance of NH in the vicinity proves the successful synthesis of COF-830 and COF-816 materials.

[0063] Figure 7 and Figure 8 The images show the SEM spectra of COF-830 prepared in Example 1 and COF-816 prepared in Comparative Example 1, respectively. Figure 7 and Figure 8 The morphological characteristics of COF-830 and COF-816 can be observed. Both COF-830 and COF-816 have a sheet-rod structure.

[0064] Figure 9 This is a comparison of the hydrogen peroxide production performance of COF-830 prepared in Example 1 (the highest yield in this invention) and COF-816 prepared in Comparative Example 1. Figure 1 shows the photocatalytic hydrogen peroxide production performance of COF-830 prepared in Example 1, which reaches a value of 2023 μmol·g⁻¹. -1 ·h -1 The photocatalytic hydrogen peroxide performance of COF-830 prepared in Example 2 can reach 1998 μmol·g. -1 ·h -1 The photocatalytic hydrogen peroxide performance of COF-830 prepared in Example 3 can reach 1946 μmol·g. -1 ·h -1 The photocatalytic hydrogen peroxide performance of COF-830 prepared in Example 4 can reach 2019 μmol·g. -1 ·h -1 2 represents the photocatalytic hydrogen peroxide performance of COF-816 prepared in Comparative Example 1, with a value of 1287 μmol·g⁻¹. -1 ·h -1 The photocatalytic hydrogen peroxide production performance of COF-830 in Example 1 is 1.57 times that of COF-816 in Example 1.

[0065] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for preparing a covalent organic framework material containing amino-substituted benzothiophene sulfone, characterized in that, Includes the following steps: Using 1,3,5-tris-(4-formyl-phenyl)triazine, amino-substituted benzothiophene sulfone, and 2,4,6-tricarboxymethyl phloroglucinol as raw materials, and mesitylene and 1,4-dioxane as solvents, a suspension was prepared. Acetic acid solution was added to the suspension, and under vacuum at 120°C, the aldehyde groups in 1,3,5-tris-(4-formyl-phenyl)triazine and 2,4,6-tricarboxymethyl phloroglucinol underwent a Schiff base reaction with the primary amine in the amino-substituted benzothiophene sulfone to obtain a covalent organic framework material containing amino-substituted benzothiophene sulfone, with the following structural formula: .

2. The method for preparing the covalent organic framework material containing amino-substituted benzothiophene sulfone according to claim 1, characterized in that, The molar ratio of 1,3,5-tris-(4-formyl-phenyl)triazine, amino-substituted benzothiophene sulfone, and 2,4,6-triformylphloroglucinol is 1:2.5~3.5:0.8~1.

2.

3. The method for preparing the covalent organic framework material containing amino-substituted benzothiophene sulfone according to claim 1, characterized in that, The volume ratio of mesitylene to 1,4-dioxane is 1.8~2.2:

3.

4. The method for preparing the covalent organic framework material containing amino-substituted benzothiophene sulfone according to claim 1, characterized in that, The molar ratio of 2,4,6-tricarboxymethyl phloroglucinol to acetic acid is 1:0.0024~0.0036.

5. The method for preparing the covalent organic framework material containing amino-substituted benzothiophene sulfone according to claim 1, characterized in that, The vacuum degree is 1×10⁻⁶. -3 Pa ~ 1×10 -1 Pa.

6. The method for preparing the covalent organic framework material containing amino-substituted benzothiophene sulfone according to claim 1, characterized in that, The Schiff base reaction time is 60h~84h.

7. The method for preparing the covalent organic framework material containing amino-substituted benzothiophene sulfone according to claim 1, characterized in that, After the Schiff base reaction is completed, the product is filtered to obtain the initial product. The initial product is then extracted using tetrahydrofuran and acetone and dried under vacuum at 60°C to obtain a covalent organic framework material containing amino-substituted benzothiophene sulfone.

8. A covalent organic framework material containing amino-substituted benzothiophene sulfone, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 7.

9. The application of the amino-substituted benzothiophene sulfone covalent organic framework material of claim 8 in the photocatalytic production of hydrogen peroxide.

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