A cofs-based flexible material and a preparation method and application thereof

Abstract

The application relates to a COFs-based flexible material and a preparation method and application thereof. Covalent organic framework powder is added into an ethyl cellulose solution, a uniformly mixed dispersion liquid is obtained through ultrasonic treatment, and then the dispersion liquid is directly cast into a film or loaded on a flexible substrate to obtain the COFs-based flexible material. Compared with the prior art, the composite material obtained by the application has excellent toughness and excellent mechanical stability, not only retains the functional characteristics of the COFs material itself, but also enhances the performance stability of the COFs material.

Description

Technical Field

[0001] This invention relates to the field of functional materials preparation technology, and in particular to a COFs-based flexible material, its preparation method, and its application. Background Technology

[0002] Covalent organic frameworks (COFs) are a class of crystalline porous organic polymers formed by organic monomers linked by covalent bonds. They possess advantages such as large specific surface area, regular pore structure, and designable functional groups, and have broad application prospects in gas separation, water treatment, adsorption, and catalysis. However, most COF materials are typically insoluble microcrystalline powders, making it difficult to process them into self-supporting macroscopic materials. While coating them onto rigid substrates can partially solve the recycling problem, it often leads to issues such as masking of active sites, increased mass transfer resistance, and easy peeling of the membrane substrate layer, thus affecting the performance of COF materials. Summary of the Invention

[0003] The purpose of this invention is to provide a COFs-based flexible material, its preparation method and application. The material has excellent toughness and good mechanical stability, and the performance stability of COFs materials is enhanced.

[0004] The objective of this invention can be achieved through the following technical solution: a method for preparing COFs-based flexible materials, wherein covalent organic framework powder is added to an ethyl cellulose (EC) solution, and a uniformly mixed dispersion is obtained by ultrasonic treatment, and then the dispersion is directly cast into a film or loaded onto a flexible substrate to obtain COFs-based flexible materials.

[0005] Preferably, the ethyl cellulose solution uses ethyl acetate as a solvent.

[0006] More preferably, in the ethyl cellulose solution, the mass-to-volume ratio of ethyl cellulose to ethyl acetate is 1.0 g: (35~45) mL.

[0007] More preferably, in the ethyl cellulose solution, the mass-to-volume ratio of ethyl cellulose to ethyl acetate is 1.0 g: 40 mL.

[0008] Preferably, the ethyl cellulose solution is prepared by dissolving ethyl cellulose in ethyl acetate and then preparing a homogeneous and transparent solution by vigorous stirring and ultrasonic treatment.

[0009] More preferably, the ultrasonic treatment conditions include: room temperature, normal pressure, 100-180W, and ultrasonic treatment for 10-20 minutes.

[0010] Preferably, the mass-to-volume ratio of the covalent organic framework powder to the ethyl cellulose solution is 10 mg: (13~17) mL.

[0011] More preferably, the mass-to-volume ratio of the covalent organic framework powder to the ethyl cellulose solution is 10 mg:15 mL.

[0012] Preferably, the covalent organic framework powder is a COFs material with photocatalytic properties.

[0013] Preferably, the covalent organic framework powder includes one or more of Tp-2,4-Pd COF, Tp-2,4-Pm COF, TpDo COF, TpBpy COF, and TpBpyAn COF.

[0014] More preferably, the preparation method of the Tp-2,4-Pd COF includes the following steps: 1,3,5-tricarboxymethyl phloroglucinol, pyridine monomers and N,N-dimethylformamide were mixed in a glass tube and subjected to multiple cycles of freezing-vacuuming-thawing for degassing. The glass tube was then vacuum-sealed and heated at a constant temperature of 110~130℃. After the reaction was completed, the product was filtered, washed, extracted and dried to obtain the Tp-2,4-Pd COF.

[0015] More preferably, the preparation method of the Tp-2,4-Pm COF includes the following steps: 1,3,5-tricarboxymethyl phloroglucinol, pyrimidine monomers and N,N-dimethylformamide were mixed in a glass tube and subjected to multiple cycles of freezing-vacuuming-thawing for degassing. The glass tube was then vacuum-sealed and kept at a constant temperature of 110~130℃ for static heating. After the reaction was completed, the product was filtered, washed, extracted and dried to obtain the Tp-2,4-Pm COF.

[0016] More preferably, the preparation method of the TpDo COF includes the following steps: 1,3,5-tricarboxymethyl phloroglucinol, 3,3'-dihydroxybenzidine, 1,4-dioxane, and mesitylene were placed in a glass tube and mixed. Acetic acid was added, and the mixture was subjected to multiple cycles of freezing-vacuuming-thawing for degassing. The glass tube was then vacuum-sealed and heated at a constant temperature of 110-130°C. After the reaction was completed, the product was filtered, washed, extracted, and dried to obtain the TpDo COF.

[0017] More preferably, the preparation method of the TpBpy COF includes the following steps: 1,3,5-tricarboxymethyl phloroglucinol, aminobipyridine, mesitylene, dioxane, and acetic acid were mixed in a glass tube and subjected to multiple cycles of freezing-vacuuming-thawing for degassing. The glass tube was then vacuum-sealed and heated at a constant temperature of 110-130°C. After the reaction was completed, the product was filtered, washed, extracted, and dried to obtain the TpBpy COF.

[0018] More preferably, the preparation method of the TpBpyAn COF includes the following steps: 1,3,5-tricarboxymethyl phloroglucinol, aminobipyridine, 2,6-diaminoanthracene, mesitylene, dioxane, and acetic acid were mixed in a glass tube and subjected to multiple cycles of freezing-vacuuming-thawing for degassing. The glass tube was then vacuum-sealed and heated at a constant temperature of 110-130°C. After the reaction was completed, the product was filtered, washed, extracted, and dried to obtain the TpBpyAn COF.

[0019] Preferably, the ultrasonic treatment conditions include: room temperature, normal pressure, 100-180W, and ultrasonic treatment for 10-20 minutes.

[0020] In this invention, the COFs powder dispersion process employs ultrasonic treatment until a uniform dispersion with no obvious particle agglomeration is formed. The ultrasonic treatment is conventional room temperature ultrasonication, requiring no additional heating or pressurization. The entire preparation process of this invention is carried out under normal temperature and pressure conditions, without the need for additional heating, pressurization, vacuuming, or other auxiliary operations.

[0021] Preferably, the process of directly casting the dispersion into a film includes: pouring the dispersion into a molding mold and allowing it to dry naturally at room temperature to obtain the COFs-based film material.

[0022] More preferably, the natural drying time is 5 to 7 hours.

[0023] More preferably, the thickness of the COFs base film material is 90-110 μm.

[0024] This invention combines the excellent processing and molding capabilities of ethyl cellulose with the rich functional properties of COFs materials, and integrates them with a room-temperature and ambient-pressure casting film-forming system to develop a versatile and easy-to-operate COFs composite membrane preparation technology. This approach eliminates the dependence of traditional processes on high-temperature, high-pressure, vacuum equipment and highly toxic solvents. It also overcomes the limitations of existing technologies that can only be applied to single COFs materials, enabling compatibility with COFs fillers of various structures. This provides a new technical approach for the low-cost, large-scale preparation and multi-field application of COFs-based functional composite membranes.

[0025] Preferably, the process of loading the dispersion onto the flexible substrate includes: placing both the dispersion and the flexible fabric in the same container, with the dispersion covering the flexible fabric, and allowing the container to dry naturally at room temperature to obtain the COFs-based flexible fabric.

[0026] More preferably, the natural drying time is 5 to 7 hours.

[0027] In this invention, COFs-based flexible fabrics are flexible and durable, porous and breathable, and can be cut to size as needed and conform to various complex structures.

[0028] In this invention, the drying process is carried out entirely at room temperature and pressure, without the use of heating or vacuum drying equipment.

[0029] A COFs-based flexible material, prepared by the above method, comprises an ethyl cellulose matrix and a covalent organic framework filler, wherein the covalent organic framework filler is uniformly dispersed within the ethyl cellulose matrix.

[0030] Preferably, the COFs-based flexible material further includes a flexible fabric on which an ethyl cellulose matrix containing covalent organic framework fillers is uniformly loaded.

[0031] An application of the above-mentioned COFs-based flexible material is to use the COFs-based flexible material for photocatalytic production of H2O2 or degradation of organic matter in high humidity environments or water.

[0032] In this invention, when the flexible material is used in photocatalytic reactions, the matrix can effectively fix the active components of COFs, prevent the loss of active materials, and improve the recycling performance of the material.

[0033] Preferably, the COFs-based flexible material is used for photocatalytic production of H2O2 or degradation of organic matter in water.

[0034] Preferably, the organic compound includes methylene blue, Congo red, and rhodamine.

[0035] An application of the above-mentioned COFs-based flexible material is to use the COFs-based flexible material in the fields of molecular sieving, water purification, and substance adsorption.

[0036] In this invention, when flexible materials are used for molecular sieving, water purification, and substance adsorption, the regular channels of COFs can be used to achieve efficient separation of molecules of different sizes and adsorption and removal of pollutants.

[0037] Compared with the prior art, the present invention has the following technical advantages: 1) By selecting an ethyl cellulose substrate and designing a preparation method, the present invention uniformly loads COFs materials, resulting in composite materials with excellent toughness and mechanical stability. This not only retains the functional characteristics of COFs materials themselves, but also enhances the performance stability of COFs materials.

[0038] 2) The COF / EC composite membrane obtained by this invention has uniform dispersion of components and complete membrane structure. It combines the good film-forming properties of ethyl cellulose substrate with the excellent functional properties of COF, and has good application prospects in the fields of molecular photocatalytic synthesis of hydrogen peroxide, photocatalytic degradation of organic matter, and odor treatment.

[0039] 3) The COFs-based flexible fabric obtained by this invention has excellent toughness, excellent mechanical stability and excellent functional properties of COF, and has good application prospects in the fields of molecular photocatalytic synthesis of hydrogen peroxide, photocatalytic degradation of organic matter, and odor treatment.

[0040] 4) This invention employs a solution blending combined with room temperature casting film formation process. It relies on mild preparation conditions to achieve composite film formation of Tp-2,4-Pd and various COFs materials with different structures and ethyl cellulose. This overcomes the problems of harsh conditions and high solvent toxicity in existing COFs composite film preparation processes, simplifies the operation process, reduces preparation costs, and ensures the integrity of the composite film structure and uniform dispersion of components.

[0041] 5) This invention uses ethyl cellulose as the film-forming matrix and ethyl acetate as the solvent, combined with a simple process of ultrasonic dispersion and room temperature casting and drying, to stably prepare composite films with various COFs doped structures; the resulting composite films have good interfacial bonding and complete overall structure, while possessing the excellent film-forming properties and mechanical flexibility of ethyl cellulose as well as the unique porous structure and functional characteristics of COFs materials.

[0042] 6) The preparation process of this invention is simple, mild, green and low in toxicity. It does not require high temperature and high pressure or complex equipment. It is easy to operate, has a short preparation cycle, and the raw materials are readily available, enabling large-scale preparation.

[0043] 7) The present invention uses a solution blending method combined with room temperature natural drying to form a film. The COFs filler is not prone to agglomeration and the pores are not easily blocked, which can fully preserve the porous structure and functional activity of the COFs themselves. At the same time, the ethyl cellulose matrix plays a good role in fixing the COFs, which improves the overall mechanical strength and cycle stability of the composite membrane.

[0044] 8) The composite membrane obtained by this invention combines the advantages of polymer matrix and COFs material, and has application potential in multiple fields such as molecular separation, water treatment, adsorption, and photocatalysis. The material function can be flexibly adjusted according to the different types of COFs selected, thus expanding the application scenarios of COFs membrane materials. Attached Figure Description

[0045] Figure 1 This is a SEM image and a physical photograph of the membrane material prepared based on Tp-2,4-Pd COF in Embodiment 1 of the present invention. Figure 2 This is a SEM image and a physical photograph of the membrane material prepared based on Tp-2,4-Pm COF in Embodiment 2 of the present invention. Figure 3 This is a SEM image and a physical photograph of the membrane material prepared based on TpDo COF in Embodiment 3 of the present invention. Figure 4 This is a SEM image and a physical photograph of the membrane material prepared based on TpBpy COF in Example 4 of the present invention. Figure 5 This is a SEM image and a physical photograph of the membrane material prepared based on TpBpyAn COF in Embodiment 5 of the present invention. Figure 6 This is a physical image of the flexible catalyst fabric prepared based on Tp-2,4-Pd COF in Example 6 of the present invention. Figure 7 This is a schematic diagram of the photocatalytic hydrogen peroxide production of the membrane material prepared based on Tp-2,4-Pd COF in Example 1 of the present invention; Figure 8 This is the result of photocatalytic degradation of methylene blue using a membrane material prepared based on Tp-2,4-Pm COF in Example 2 of the present invention. Figure 9 This is the result of photocatalytic degradation of Congo red using a membrane material prepared based on TpDo COF in Example 3 of the present invention; Figure 10 This is the result of photocatalytic degradation of rhodamine using a membrane material based on TpBpy COF in Example 4 of the present invention. Figure 11 This is the result of photocatalytic degradation of rhodamine by a flexible step material based on Tp-2,4-Pd COF in Example 6 of the present invention. Figure 12 This is a detailed SEM image of the membrane material prepared based on Tp-2,4-Pd COF in Example 1 of the present invention. Figure 13 This is a detailed SEM image of the membrane material prepared based on Tp-2,4-Pm COF in Example 2 of the present invention. Figure 14This is a detailed SEM image of the membrane material prepared based on TpDo COF in Example 3 of the present invention. Figure 15 This is a detailed SEM image of the membrane material prepared based on TpBpy COF in Example 4 of the present invention. Figure 16 This is a detailed SEM image of the membrane material prepared based on TpBpyAn COF in Example 5 of the present invention. Detailed Implementation

[0046] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0047] Unless otherwise specified, the reagents, methods, instruments, and equipment used in this invention are conventional in the art. Unless otherwise specified, the reagents and materials used in the following examples are all commercially available.

[0048] In the following examples, Tp-2,4-Pd COF was prepared using the following process: 42 mg (0.2 mmol) of 1,3,5-tricarboxymethyl phloroglucinol (Tp) and 33.5 mg (0.3 mmol) of a pyridine monomer (2,4-Pd) were placed in a 20 mL hard glass tube, and 10 mL of N,N-dimethylformamide (DMF) was added. The hard glass tube was then sonicated for 20 minutes to ensure uniform dispersion of the materials. The reaction system was then subjected to three consecutive freeze-evacuation-thawing cycles for degassing. The glass tube was then vacuum-sealed and heated at 120°C for 72 hours. After the reaction, the yellow solid powder was collected by filtration and washed successively with dichloromethane and subjected to Soxhlet extraction with tetrahydrofuran. The obtained product was dried under vacuum at 80°C for 12 hours, yielding 65.3 mg of Tp-2,4-Pd, with a yield of 82%.

[0049] Tp-2,4-Pm COF was prepared as follows: 42 mg (0.2 mmol) of 1,3,5-tricarboxymethyl phloroglucinol (Tp) and 33.3 mg (0.3 mmol) of a pyrimidine monomer (2,4-Pm) were placed in a 20 mL hard glass reaction tube containing 10 mL of N,N-dimethylformamide (DMF). The hard glass tube was then sonicated for 20 minutes to ensure uniform dispersion of the materials. The reaction system was then subjected to three consecutive freeze-evacuation-thawing cycles to remove gases. The reaction tube was then vacuum-sealed and heated undisturbed at 120°C for 72 hours. After the reaction, the yellow solid powder was collected by filtration, washed with dichloromethane, and then extracted with tetrahydrofuran using a Soxhlet extractor. The resulting product was dried under vacuum at 80°C for 12 hours to obtain Tp-2,4-Pm (68.6 mg, 83% yield).

[0050] TpDo COF was prepared as follows: 42.1 mg (0.2 mmol) of 1,3,5-tricarboxymethyl phloroglucinol (Tp) and 65 mg (0.3 mmol) of 3,3'-dihydroxybenzidine (DO) were placed in a 10 mL hard glass tube, along with 1.5 mL of 1,4-dioxane and 1.5 mL of mesitylene. The hard glass tube was then sonicated for 20 minutes to ensure uniform dispersion of the materials. 0.3 mL of 6 mol / L acetic acid was added to the system, followed by three consecutive freeze-evacuation-thawing cycles to remove gases. The glass tube was then vacuum-sealed and the reaction was allowed to proceed at 120°C for 72 hours. After the reaction, the red solid powder was collected by filtration and washed sequentially with dichloromethane and extracted with tetrahydrofuran using a Soxhlet extractor. The product was then vacuum-dried at 80°C for 12 hours to obtain TpDo covalent organic framework material with a mass of 86.8 mg and a yield of 81%.

[0051] The TpBpy COF was prepared as follows: 0.2 mmol Tp (42.0 mg) and 0.3 mmol aminobipyridine (55.8 mg) were added to a 10 mL hard glass tube containing 0.8 mL mesitylene, 0.2 mL dioxane, and 0.1 mL acetic acid at 6 mol / L. The mixture was sonicated for 10 min, degassed by three cycles of freezing-vacuuming-thawing, and then vacuum-sealed. The mixture was reacted at 120°C for 3 days, and after natural cooling to room temperature, the solid precipitate was collected by filtration and washed repeatedly with tetrahydrofuran and acetone. The resulting solid precipitate was then subjected to Soxhlet extraction with tetrahydrofuran for 12 h, followed by vacuum drying at 40°C for 24 h to obtain the TpBpy covalent organic framework material (88 mg, 90% yield).

[0052] The TpBpyAn COF was prepared as follows: 0.1 mmol Tp (21.0 mg), 0.075 mmol aminobipyridine (14.0 mg), and 0.075 mmol 2,6-diaminoanthracene (An-NH2, 15.6 mg) were added to a 10 mL hard glass tube containing 0.8 mL mesitylene, 0.2 mL dioxane, and 0.1 mL acetic acid at 6 mol / L. The mixture was sonicated for 10 min, degassed by three cycles of freezing-vacuuming-thawing, and then vacuum-sealed. The mixture was reacted at 120°C for 3 days, and after natural cooling to room temperature, the solid precipitate was collected by filtration and washed repeatedly with tetrahydrofuran and acetone. The resulting solid precipitate was then subjected to Soxhlet extraction with tetrahydrofuran for 12 h and vacuum drying at 40°C for 24 h to obtain the TpBpyAn covalent organic framework material (40 mg, 92% yield).

[0053] Example 1 A method for preparing a Tp-2,4-Pd / EC catalyst membrane by compositing COF material with EC sol using a simple sol-gel method includes the following steps: 1 g of ethyl cellulose and 40 mL of ethyl acetate were mixed in a glass conical flask and stirred vigorously. The mixture was then sonicated at 150 W for 15 minutes to obtain a clear and transparent EC (ethyl cellulose) sol. 10 mg of Tp-2,4-Pd COF powder was mixed with 15 mL of EC sol and added to the conical flask. The mixture was stirred vigorously and sonicated for 10 minutes to obtain a uniformly dispersed and non-agglomerated Tp-2,4-Pd / EC sol. The obtained Tp-2,4-Pd / EC sol was spread evenly on a 6 cm diameter glass petri dish and allowed to air dry naturally in a well-ventilated environment at room temperature. The film material was then gently peeled off with a small spatula to obtain the Tp-2,4-Pd / EC catalyst film material (Tp-2,4-Pd / EC).

[0054] SEM images and physical images of the prepared Tp-2,4-Pd / EC catalyst membrane are shown below. Figure 1 As shown, from Figure 1 As can be seen from the SEM images, the Tp-2,4-Pd material retains its original microstructure after the introduction of EC. The porous framework structure indicates that the Tp-2,4-Pd / EC catalyst film possesses excellent gas permeation performance in photocatalytic reactions. Figure 1 The Tp-2,4-Pd / EC catalyst membrane, as shown in the physical image, exhibits excellent toughness and superior mechanical stability, demonstrating its potential for practical application.

[0055] Example 2 A method for preparing a Tp-2,4-Pm / EC catalyst membrane by compositing COF material with EC sol using a simple sol-gel method includes the following steps: 1 g of ethyl cellulose and 40 mL of ethyl acetate were mixed in a glass conical flask and stirred vigorously. The mixture was then sonicated at 150 W for 15 minutes to obtain a clear and transparent EC (ethyl cellulose) sol. 10 mg of Tp-2,4-Pm COF powder was mixed with 15 mL of EC sol and added to the conical flask. The mixture was stirred vigorously and sonicated for 10 minutes to obtain a uniformly dispersed and non-agglomerated Tp-2,4-Pm / EC sol. The obtained Tp-2,4-Pm / EC sol was spread evenly on a 6 cm diameter glass petri dish and allowed to air dry naturally in a well-ventilated environment at room temperature. The film material was then gently peeled off with a small spatula to obtain the Tp-2,4-Pm / EC catalyst film material (Tp-2,4-Pm / EC).

[0056] SEM images and physical images of the prepared Tp-2,4-Pm / EC catalyst membrane are shown below. Figure 2 As shown, from Figure 2 As can be seen from the SEM images, the Tp-2,4-Pm material retains its original microstructure after the introduction of EC. The presence of a porous framework structure indicates that the Tp-2,4-Pm / EC catalyst film possesses excellent gas permeation performance in photocatalytic reactions. Figure 2 The Tp-2,4-Pm / EC catalyst membrane, as shown in the physical image, exhibits excellent toughness and superior mechanical stability, demonstrating its potential for practical application.

[0057] Example 3 A method for preparing a TpDo / EC catalyst membrane by combining COF material with EC sol via a simple sol-gel method includes the following steps: 1g of ethyl cellulose and 40ml of ethyl acetate were mixed in a glass conical flask and stirred vigorously. The mixture was then sonicated at 150W for 15 minutes to obtain a clear and transparent EC (ethyl cellulose) sol. 10mg of TpDo COF powder was mixed with 15ml of EC sol and added to the conical flask. The mixture was stirred vigorously and sonicated for 10 minutes to obtain a uniformly dispersed TpDo / EC sol without agglomeration. The obtained TpDo / EC sol was spread evenly on a 6cm diameter glass petri dish and allowed to air dry naturally in a well-ventilated environment at room temperature. The film material was then gently peeled off with a small spatula to obtain the TpDo / EC catalyst film material (TpDo / EC).

[0058] SEM images and physical images of the prepared TpDo / EC catalyst membrane are shown below. Figure 3 As shown, from Figure 3As can be seen from the SEM images, the TpDo material retains its original microstructure after the introduction of EC. The porous framework structure indicates that the TpDo / EC catalyst film possesses excellent gas permeation performance in photocatalytic reactions. Figure 3 The TpDo / EC catalyst membrane, as shown in the physical image, exhibits excellent toughness and superior mechanical stability, demonstrating its potential for practical applications.

[0059] Example 4 A method for preparing a TpBpy / EC catalyst membrane by compositing COF material with EC sol using a simple sol-gel method includes the following steps: 1 g of ethyl cellulose and 40 mL of ethyl acetate were mixed in a glass conical flask and stirred vigorously. The mixture was then sonicated at 150 W for 15 minutes to obtain a clear and transparent EC (ethyl cellulose) sol. 10 mg of TpBpy COF powder was mixed with 15 mL of EC sol and added to the conical flask. The mixture was stirred vigorously and sonicated for 10 minutes to obtain a uniformly dispersed TpBpy / EC sol without agglomeration. The obtained TpBpy / EC sol was spread evenly on a 6 cm diameter glass petri dish and allowed to air dry naturally in a well-ventilated environment at room temperature. The film material was then gently peeled off with a small spatula to obtain the TpBpy / EC catalyst film material (TpBpy / EC).

[0060] SEM images and physical images of the prepared TpBpy / EC catalyst membrane are shown below. Figure 4 As shown, from Figure 4 As can be seen from the SEM images, the TpBpy material retains its original microstructure after the introduction of EC. The porous framework structure indicates that the TpBpy / EC catalyst film possesses excellent gas permeation performance in photocatalytic reactions. Figure 4 The TpBpy / EC catalyst membrane, as shown in the physical image, exhibits excellent toughness and superior mechanical stability, demonstrating its potential for practical applications.

[0061] Example 5 A method for preparing a TpBpyAn / EC catalyst membrane by compositing COF material with EC sol using a simple sol-gel method includes the following steps: 1 g of ethyl cellulose and 40 mL of ethyl acetate were mixed in a glass conical flask and stirred vigorously. The mixture was then sonicated at 150 W for 15 minutes to obtain a clear and transparent EC (ethyl cellulose) sol. 10 mg of TpBpyAn COF powder was mixed with 15 mL of EC sol and added to the conical flask. The mixture was stirred vigorously and sonicated for 10 minutes to obtain a uniformly dispersed TpBpyAn / EC sol without agglomeration. The obtained TpBpyAn / EC sol was spread evenly on a 6 cm diameter glass petri dish and allowed to air dry naturally in a well-ventilated environment at room temperature. The film material was then gently peeled off with a small spatula to obtain the TpBpyAn / EC catalyst film material (TpBpyAn / EC).

[0062] SEM schematic and physical image of the prepared TpBpyAn / EC catalyst membrane are shown below. Figure 5 As shown, from Figure 5 As can be seen from the SEM images, the TpBpyAn material retains its original microstructure after the introduction of EC. The porous framework structure indicates that the TpBpyAn / EC catalyst film possesses excellent gas permeation performance in photocatalytic reactions. Figure 5 The TpBpyAn / EC catalyst membrane, as shown in the physical image, exhibits excellent toughness and superior mechanical stability, demonstrating its potential for practical applications.

[0063] Example 6 A method for preparing a Tp-2,4-Pd / EC flexible fabric by composited COF material with EC sol using a simple impregnation coating method includes the following steps: 1 g of ethyl cellulose and 40 mL of ethyl acetate were mixed in a glass conical flask and stirred vigorously. The mixture was then sonicated at 150 W for 15 minutes to obtain a clear and transparent EC (ethyl cellulose) sol. 10 mg of Tp-2,4-Pd COF powder was mixed with 15 mL of EC sol and added to the conical flask. The mixture was stirred vigorously and sonicated for 10 minutes to obtain a uniformly dispersed and non-agglomerated Tp-2,4-Pd / EC sol. The obtained Tp-2,4-Pd / EC sol was spread evenly on a 6 cm diameter glass petri dish. Flexible fabric was then cut into suitable shapes and placed in the petri dish containing the Tp-2,4-Pd / EC sol for 2 hours. Afterward, the fabric was removed and allowed to air dry naturally in a well-ventilated environment at room temperature to obtain the Tp-2,4-Pd / EC flexible fabric material.

[0064] A physical image of the prepared flexible fabric for the Tp-2,4-Pd / EC catalyst is shown below. Figure 6 As shown, in Figure 6 The physical image shows that the flexible fabric of the Tp-2,4-Pd / EC catalyst exhibits excellent toughness and good mechanical stability, demonstrating its potential for practical application.

[0065] Example 7 Tests on photocatalytic hydrogen peroxide production using Tp-2,4-Pd / EC catalyst membrane materials: (1) Take a circular Tp-2,4-Pd / EC catalyst membrane material with a diameter of 6 cm prepared in Example 1 and 40 ml of deionized water into the photocatalytic reactor; (2) Irradiate the above solution with light for three hours, and take the supernatant every half hour to test the hydrogen peroxide yield; (3) Record the data and quantify the hydrogen peroxide yield using the hydrogen peroxide production standard curve. Collect the hydrogen peroxide yield for each time period and plot it.

[0066] like Figure 7 As shown, the Tp-2,4-Pd / EC catalyst membrane material exhibits excellent catalytic performance in the photocatalytic hydrogen peroxide production reaction: within a 3-hour reaction time, the Tp-2,4-Pd / EC catalyst membrane achieved 1398.8 mmol / L hydrogen peroxide. g -1 m -2 h -1 The Tp-2,4-Pd / EC catalyst membrane not only retains the excellent photocatalytic hydrogen peroxide production performance of Tp-2,4-Pd material, but also significantly improves the stability of the catalytic reaction after being made into a catalyst membrane.

[0067] Example 8 Tests on the photocatalytic degradation of methylene blue dye using Tp-2,4-Pm / EC catalyst membrane materials: (1) Take a circular Tp-2,4-Pm / EC catalyst membrane material with a diameter of 6 cm prepared in Example 2 and 40 mL of methylene blue aqueous solution with a concentration of 10 mg / L into the photocatalytic reactor; (2) Irradiate the above solution with light for three hours. Take 2 mL of the supernatant at fixed time intervals and measure the absorption peak with a UV-Vis spectrophotometer to compare with the absorption peak of the initial concentration of methylene blue solution to test the efficiency of photocatalytic degradation of methylene blue solution. (3) Record data. Collect the absorption peaks of the methylene blue solution for each time period and plot them.

[0068] like Figure 8 As shown, the Tp-2,4-Pm / EC catalyst membrane material exhibits excellent degradation performance in the photocatalytic degradation of methylene blue solution: within a 3-hour reaction time, the Tp-2,4-Pm / EC catalyst membrane achieved a photocatalytic degradation efficiency of 40%. The Tp-2,4-Pm / EC catalyst membrane not only retains the excellent photocatalytic degradation performance of Tp-2,4-Pm material in degrading methylene blue solution, but also significantly improves the stability of the photocatalytic degradation reaction after being made into a catalyst membrane.

[0069] Example 9 Tests on the photocatalytic degradation of Congo red dye using TpDo / EC catalyst membrane materials: (1) Take a circular TpDo / EC catalyst membrane material with a diameter of 6 cm prepared in Example 3 and 40 mL of Congo red aqueous solution with a concentration of 10 mg / L and place it in the photocatalytic reactor; (2) Irradiate the above solution with light for three hours. Take 2 ml of the supernatant at fixed time intervals and measure the absorption peak with a UV-Vis spectrophotometer to compare with the absorption peak of the initial concentration of Congo red solution to test the efficiency of photocatalytic degradation of Congo red solution. (3) Record data. Collect the absorption peaks of the Congo red solution for each time period and plot them.

[0070] like Figure 9 As shown, the TpDo / EC catalyst membrane material exhibits excellent degradation performance in the photocatalytic degradation of Congo red solution: within a 3-hour reaction time, the TpDo / EC catalyst membrane achieved a photocatalytic degradation efficiency of 81%. The TpDo / EC catalyst membrane not only retains the excellent photocatalytic degradation performance of TpDo material in Congo red solution, but also significantly improves the stability of the photocatalytic degradation reaction after being made into a catalyst membrane.

[0071] Example 10 Tests on the photocatalytic degradation of Rhodamine dye using TpBpy / EC catalyst membrane materials: (1) Take a circular TpBpy / EC catalyst membrane material with a diameter of 6 cm prepared in Example 4 and 40 mL of Rhodamine aqueous solution with a concentration of 10 mg / L and place it in the photocatalytic reactor; (2) Irradiate the above solution with light for three hours. Take 2 ml of the supernatant at fixed time intervals and measure the absorption peak with a UV-Vis spectrophotometer to compare with the absorption peak of the initial concentration of rhodamine solution to test the efficiency of photocatalytic degradation of rhodamine solution. (3) Record data. Collect the absorption peaks of the rhodamine solution for each time period and plot them.

[0072] like Figure 10 As shown, the TpBpy / EC catalyst membrane material exhibits excellent degradation performance in the photocatalytic degradation of rhodamine solution: within a 3-hour reaction time, the TpBpy / EC catalyst membrane achieved a photocatalytic degradation efficiency of 40%. The TpBpy / EC catalyst membrane not only retains the excellent photocatalytic degradation performance of TpBpy material in rhodamine solution, but also significantly improves the stability of the photocatalytic degradation reaction after being made into a catalyst membrane.

[0073] Example 11 Tests on the photocatalytic degradation of Rhodamine dyes in flexible fabrics using Tp-2,4-Pd / EC catalysts: (1) Take a square Tp-2,4-Pd / EC catalyst flexible cloth with a side length of 6 cm prepared in Example 6 and 40 mL of Rhodamine aqueous solution with a concentration of 10 mg / L and place it in the photocatalytic reactor; (2) Irradiate the above solution with light for three hours. Take 2 ml of the supernatant at fixed time intervals and measure the absorption peak with a UV-Vis spectrophotometer to compare with the absorption peak of the initial concentration of rhodamine solution to test the efficiency of photocatalytic degradation of rhodamine solution. (3) Record data. Collect the absorption peaks of the rhodamine solution for each time period and plot them.

[0074] like Figure 11 As shown, in the photocatalytic degradation of rhodamine solution, the Tp-2,4-Pd / EC catalyst flexible fabric exhibits excellent degradation performance: within a 3-hour reaction time, the Tp-2,4-Pd / EC catalyst flexible fabric achieved a photocatalytic degradation efficiency of 39%. The Tp-2,4-Pd / EC catalyst flexible fabric not only retains the excellent photocatalytic degradation performance of Tp-2,4-Pd materials in the degradation of rhodamine solution, but also significantly improves the stability of the photocatalytic degradation reaction after being made into a catalyst flexible fabric.

[0075] Details of the membrane materials in Examples 1-5 are as follows: Figures 12-16 As shown, this COF membrane successfully formed a dense surface layer and a porous interior structure. The tight overlap of the surface ensures the continuity and density of the membrane, and the stacking of layers inside the cross section forms a through-pore channel. The overall thickness is uniform, there are no obvious macroscopic cracks, and the film quality is excellent. The COF material achieves good layer assembly and stacking inside the membrane.

[0076] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for preparing a COFs-based flexible material, characterized in that, Covalent organic framework powder is added to an ethyl cellulose solution and ultrasonically treated to obtain a uniformly mixed dispersion. The dispersion is then directly cast into a film or loaded onto a flexible substrate to obtain a COFs-based flexible material.

2. The method for preparing COFs-based flexible materials according to claim 1, characterized in that, The ethyl cellulose solution uses ethyl acetate as a solvent.

3. The method for preparing COFs-based flexible materials according to claim 2, characterized in that, In the ethyl cellulose solution, the mass-to-volume ratio of ethyl cellulose to ethyl acetate is 1.0 g: (35~45) mL.

4. The method for preparing COFs-based flexible materials according to claim 1, characterized in that, The mass-to-volume ratio of the covalent organic framework powder to the ethyl cellulose solution is 10 mg: (13~17) mL.

5. The method for preparing COFs-based flexible materials according to claim 1, characterized in that, The covalent organic framework powder is a COFs material with photocatalytic properties.

6. The method for preparing COFs-based flexible materials according to claim 1, characterized in that, The covalent organic framework powder includes one or more of Tp-2,4-Pd COF, Tp-2,4-Pm COF, TpDo COF, TpBpy COF, and TpBpyAn COF.

7. The method for preparing COFs-based flexible materials according to claim 1, characterized in that, The process of directly casting the dispersion into a film includes: pouring the dispersion into a molding mold and allowing it to dry naturally at room temperature to obtain COFs-based film material.

8. The method for preparing COFs-based flexible materials according to claim 1, characterized in that, The process of loading a dispersion onto a flexible substrate includes: placing both the dispersion and the flexible fabric in the same container, with the dispersion covering the flexible fabric, and then allowing the container to air dry at room temperature to obtain a COFs-based flexible fabric.

9. A COFs-based flexible material, characterized in that, The product is prepared by any one of claims 1 to 8, comprising an ethyl cellulose matrix and a covalent organic framework filler, wherein the covalent organic framework filler is uniformly dispersed within the ethyl cellulose matrix.

10. An application of the COFs-based flexible material according to claim 9, characterized in that, The COFs-based flexible material is used for photocatalytic H2O2 production or organic matter degradation in high humidity environments or in water.

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