Preparation method and application of hydrogen-bonded organic framework nanosheets based on amide compounds

Abstract

The present invention discloses a preparation method and application of hydrogen-bonded organic framework nanosheets based on amide compounds, belonging to the technical field of functional material preparation. Using 1,3,5-tris(4-methylphenyl)benzene, thionyl chloride, and ammonia water as raw materials, an amide compound C 27 H 21 N3O3 for constructing a hydrogen-bonded organic framework was prepared; using dimethyl sulfoxide as a good solvent and tetrahydrofuran as a poor solvent, the target hydrogen-bonded organic framework crystal was obtained by a solvent phase transfer method; subsequently, hydrogen-bonded organic framework nanosheets were prepared by ultrasonic exfoliation, and their proton conductivity performance was explored.

Description

Technical Field

[0001] The present invention relates to a preparation method and application of hydrogen-bonded organic framework nanosheets based on amide compounds. The prepared nanosheets have excellent proton conductivity and belong to the technical field of functional nanomaterial preparation. Technical Background

[0002] Proton conducting materials are a type of ionic conductor with protons as charge carriers. Currently, proton conducting materials have been widely used in fields such as proton exchange membrane fuel cells, sensing, and bionic devices. Common proton conducting materials are mainly organic polymers (such as perfluorosulfonic acid). However, the preparation process of such proton conductors is complex, the cost is high, and the operating temperature range is narrow. In recent years, porous crystalline materials (such as metal-organic frameworks and covalent-organic frameworks) have received extensive attention as new proton conducting materials. Currently, the proton conductivity of such materials has reached or even exceeded 10 -2 S·cm -1 . However, the preparation conditions of the above-mentioned porous crystalline materials are relatively harsh. Therefore, people are committed to developing new proton conducting porous crystalline materials with high performance.

[0003] Hydrogen-bonded organic frameworks are a type of porous crystalline materials formed by intermolecular hydrogen bond interactions. Hydrogen-bonded organic frameworks are similar to metal-organic frameworks and covalent-organic frameworks, and have advantages such as high specific surface area and adjustable pore structure. In addition, compared with covalent bonds and coordination bonds, hydrogen bonds have weaker directionality, lower bond energy, and reversibility. Therefore, hydrogen-bonded organic frameworks exhibit some unique properties, such as mild synthesis conditions and easy regeneration. Currently, hydrogen-bonded organic frameworks have been widely used in fields such as gas separation and storage, sensing, etc. At the same time, the rich hydrogen bond interactions inside the hydrogen-bonded organic frameworks will be beneficial to the construction of proton transport paths. Therefore, hydrogen-bonded organic frameworks have certain potential in proton conductivity. Summary of the Invention

[0004] To solve the above technical problems, the present invention provides a preparation method of hydrogen-bonded organic framework nanosheets based on amide compounds. By a simple solvent phase transfer method combined with ultrasonic exfoliation method, hydrogen-bonded organic framework nanosheets with rich hydrogen bonds inside are prepared. Combining with a pore structure that is conducive to the adsorption of water molecules, it promotes the construction of proton transport paths inside the material, and proton conducting hydrogen-bonded organic framework nanosheets with excellent performance are obtained.

[0005] The technical solution proposed to solve the above technical problems is: A preparation method of hydrogen-bonded organic framework nanosheets based on amide compounds, comprising the following steps:

[0006] (1) Mix the amide compound C 27 H 21 N3O3 Dissolved in dimethyl sulfoxide;

[0007] (2) Using the solvent phase transfer method, slowly diffuse the poor solvent into the solution obtained in step (1) to precipitate the target hydrogen-bonded organic framework crystals;

[0008] (3) Ultrasonically exfoliate the crystals obtained in step (2), with water as the ultrasonic solvent, to obtain hydrogen-bonded organic framework nanosheets.

[0009] Preferably, the amide compound C 27 H 21 N3O3 is prepared from 1,3,5-tris(4-methylphenyl)benzene, thionyl chloride, and ammonia water as raw materials.

[0010] Preferably, the preparation method of the amide compound C 27 H 21 N3O3 is as follows: Mix 2.0 g of 1,3,5-tris(4-methylphenyl)benzene, 6 mL of water, and 3 mL of concentrated nitric acid in a polytetrafluoroethylene reaction kettle. After reacting at 170 °C for 24 h, wash the product with water and recrystallize it with methanol to obtain 1,3,5-tris(4-carboxyphenyl)benzene; then dissolve 1.0 g of 1,3,5-tris(4-carboxyphenyl)benzene in 30 mL of thionyl chloride, and simultaneously add a few drops of N,N-dimethylformamide as a catalyst. After reacting at 95 °C for 12 h, remove the excess thionyl chloride, then add 150 mL of ammonia water, react at room temperature for 24 h, filter out the product, and recrystallize it with methanol to obtain the amide compound C 27 H 21 N3O3.

[0011] Preferably, the concentration of the dimethyl sulfoxide solution of the amide compound in step (1) is 20 - 60 mmol / L.

[0012] Preferably, the poor solvent in step (2) is tetrahydrofuran, the diffusion time is 3 - 5 days, and the volume ratio of the poor solvent to dimethyl sulfoxide is 5:1 - 2:1.

[0013] Preferably, the ultrasonic time in step (3) is 6 - 18 h.

[0014] To solve the above technical problems, another technical solution is proposed: hydrogen-bonded organic framework nanosheets based on amide compounds prepared by any method.

[0015] To solve the above technical problems, another technical solution is proposed: the application of the hydrogen-bonded organic framework nanosheets based on amide compounds, and this material has excellent proton conductivity performance.

[0016] Preferably, the dispersion of hydrogen-bonded organic framework nanosheets is drop-coated on the surface of interdigitated electrodes and dried naturally for testing its proton conductivity performance.

[0017] Preferably, it is applied to fuel cells, sensing and catalysis.

[0018] The beneficial effects of the present invention are as follows:

[0019] 1. In the present invention, hydrogen-bonded organic framework nanosheets are prepared by a solvent phase transfer method combined with an ultrasonic exfoliation method, with simple operation and easy mass production.

[0020] 2. By utilizing the intermolecular hydrogen bond interaction, the present invention forms a hydrogen-bonded organic framework with a pore structure, which is beneficial to the adsorption of water molecules.

[0021] 3. By utilizing the abundant hydrogen bond interactions and adsorbed water molecules inside the hydrogen-bonded organic framework nanosheets, the present invention promotes the construction of proton transport channels.

[0022] 4. The hydrogen-bonded organic framework nanosheets of the present invention have excellent proton conductivity. Under the conditions of 296K and 98% relative humidity, the proton conductivity can reach 1.34×10 -2 S·cm -1 , which is at the same level as the commercial proton conductor Nafion. Description of the Drawings

[0023] Figure 1 Synthesis route of C 27 H 21 N3O3 of the amide compound in Example 1.

[0024] Figure 2 C of the amide compound in Example 1 27 H 21 H of N3O3 1 NMR spectrum.

[0025] Figure 3 C of the amide compound in Example 1 27 H 21 C of N3O3 12 NMR spectrum.

[0026] Figure 4 XRD pattern of the hydrogen-bonded organic framework nanosheets in Example 2.

[0027] Figure 5 SEM image of the hydrogen-bonded organic framework nanosheets in Example 2.

[0028] Figure 6 Schematic diagram of the structure of the hydrogen-bonded organic framework nanosheets in Example 2.

[0029] Figure 7 Water adsorption and desorption diagram of the hydrogen-bonded organic framework nanosheet in Example 2.

[0030] Figure 8 Nyquist curve diagram of the hydrogen-bonded organic framework nanosheet in Example 6 at 98% relative humidity between 296K and 314K.

[0031] Figure 9 Arrhenius diagram of the hydrogen-bonded organic framework nanosheet in Example 6 at 98% relative humidity between 296K and 314K.

[0032] Figure 10 Proton conductivity change diagram of the hydrogen-bonded organic framework nanosheet in Example 6 at 98% relative humidity between 296K and 314K.

[0033] Figure 11 Nyquist diagram of the hydrogen-bonded organic framework nanosheet under the conditions of 296K and 98% relative humidity. Detailed implementation manners

[0034] In order to better understand the present invention, the technical solutions of the present invention will be specifically described below with reference to the accompanying drawings through specific examples.

[0035] Example 1: Preparation method of amide compound

[0036] (1) 2.0 g of 1,3,5-tris(4-methylphenyl)benzene, 6 mL of deionized water and 3 mL of concentrated nitric acid were mixed in a tetrafluoroethylene reaction kettle, and reacted at 170 °C for 24 h. The product was washed with water until neutral, and recrystallized with methanol as the solvent to obtain the first-step product 1,3,5-tris(4-carboxyphenyl)benzene.

[0037] (2) 1.0 g of 1,3,5-tris(4-carboxyphenyl)benzene was dissolved in 30 mL of thionyl chloride, and a few drops of dimethylformamide were added dropwise as a catalyst. The reaction was carried out at 95 °C for 12 h. Excess thionyl chloride was removed by reduced pressure distillation. Subsequently, 150 mL of ammonia water was added to the residue under ice bath conditions, and the reaction was carried out at room temperature for 24 h. The product was filtered out, washed with water, and recrystallized with methanol as the solvent to obtain the amide compound C 27 H 21 N3O3.

[0038] Analyze the product C 27 H 21 N3O3 in Example 1. As Figure 2 shown, the H 27 H 21 NMR diagram of the amide compound C 1 N3O3. As Figure 3 shown, the amide compound C 27 H21 C of N3O3 12 NMR spectrum, through H 1 NMR spectrum and C 12 The NMR spectrum can illustrate that the obtained amide compound is consistent with Figure 1 the product structure in

[0039] Example 2: Preparation method of hydrogen-bonded organic framework nanosheets

[0040] (1) Take 200 mg of amide compound C 27 H 21 N3O3 and dissolve it in 10 mL of dimethyl sulfoxide.

[0041] (2) Using the solvent phase transfer method, add 10 mL of tetrahydrofuran dropwise to the upper layer of 2 mL of the above solution, and prepare hydrogen-bonded organic framework crystals by solvent diffusion. The diffusion time is 4 days.

[0042] (3) Using water as the solvent, ultrasonicate the hydrogen-bonded organic framework crystals for 12 h to obtain hydrogen-bonded organic framework crystal nanosheets.

[0043] Analyze the product hydrogen-bonded organic framework nanosheets in Example 2. As Figure 4 shown, the XRD pattern of the hydrogen-bonded organic framework nanosheets is consistent with the single crystal simulation result. As Figure 5 shown, the SEM image of the hydrogen-bonded organic framework nanosheets. Through the SEM image, it can be illustrated that hydrogen-bonded organic framework crystal nanosheets are finally prepared. As Figure 6 shown, the structure schematic diagram of the hydrogen-bonded organic framework nanosheets. The hydrogen-bonded organic framework nanosheets have a pore structure. As Figure 7 shown, the water adsorption and desorption diagram of the hydrogen-bonded organic framework nanosheets. The hydrogen-bonded organic framework nanosheets can effectively adsorb water molecules.

[0044] Example 3: Preparation method of hydrogen-bonded organic framework nanosheets

[0045] (1) Take 200 mg of amide compound C 27 H 21 N3O3 and dissolve it in 15 mL of dimethyl sulfoxide.

[0046] (2) Using the solvent phase transfer method, add 8 mL of tetrahydrofuran dropwise to the upper layer of 2 mL of the above solution, and prepare hydrogen-bonded organic framework crystals by solvent diffusion. The diffusion time is 3 days.

[0047] (3) Using water as the solvent, ultrasonicate the hydrogen-bonded organic framework crystals for 12 h to obtain hydrogen-bonded organic framework crystal nanosheets.

[0048] Using Example 3 can also obtain the product hydrogen-bonded organic framework crystal nanosheets in Example 2.

[0049] Example 4: Preparation Method of Hydrogen Bonded Organic Framework Nanosheets

[0050] (1) Take 150 mg of amide compound C 27 H 21 N3O3 and dissolve it in 5 mL of dimethyl sulfoxide.

[0051] (2) Using the solvent phase transfer method, add 10 mL of tetrahydrofuran dropwise onto the upper layer of 2 mL of the above solution, and prepare hydrogen-bonded organic framework crystals by solvent diffusion. The diffusion time is 5 days.

[0052] (3) Using water as the solvent, ultrasonicate the hydrogen-bonded organic framework crystals for 12 h to obtain hydrogen-bonded organic framework crystal nanosheets.

[0053] Using Example 4 can also obtain the product hydrogen-bonded organic framework crystal nanosheets in Example 2.

[0054] Example 5: Preparation Method of Hydrogen Bonded Organic Framework Nanosheets

[0055] (1) Take 200 mg of amide compound C 27 H 21 N3O3 and dissolve it in 10 mL of dimethyl sulfoxide.

[0056] (2) Using the solvent phase transfer method, add 6 mL of tetrahydrofuran dropwise onto the upper layer of 2 mL of the above solution, and prepare hydrogen-bonded organic framework crystals by solvent diffusion. The diffusion time is 4 days.

[0057] (3) Using water as the solvent, ultrasonicate the hydrogen-bonded organic framework crystals for 18 h to obtain hydrogen-bonded organic framework crystal nanosheets.

[0058] Using Example 5 can also obtain the product hydrogen-bonded organic framework crystal nanosheets in Example 2.

[0059] Example 6: Proton Conductivity Performance Test of Hydrogen Bonded Organic Framework Crystal Nanosheets

[0060] (1) Drop-coat the hydrogen-bonded organic framework crystal nanosheets in Example 2 onto the interdigitated electrodes. The two ends of the interdigitated electrodes are connected to an electrochemical workstation (Autolab 302N) through wires. At a specified temperature of 98% relative humidity, the proton conductivity performance of this derivative is tested through the electrochemical workstation.

[0061] (2) Test the electrochemical impedance spectrum of this derivative at 98% relative humidity between 296 K and 314 K, obtain its corresponding Nyquist curve graph, and calculate its proton conductivity through fitting.

[0062] (3) Plot and fit according to the Arrhenius formula to obtain the proton conduction activation energy of the derivative at 98% relative humidity between 296K and 314K.

[0063] Analyze the above test results, as Figure 6 shown, the electrochemical impedance spectra of the hydrogen-bonded organic framework nanosheet derivatives are different at different temperatures. Due to the proton hopping caused by thermal activation, its resistance value is higher at lower temperatures; at higher temperatures, its resistance value is lower.

[0064] As Figure 7 shown, the proton conduction activation energy of the hydrogen-bonded organic framework nanosheets is 0.33 eV at 98% relative humidity between 296K and 314K, and the proton conduction process follows the hopping mechanism.

[0065] As Figure 8 shown, the proton conductivity of the hydrogen-bonded organic framework nanosheets is 1.34×10 -2 S cm -1 at 296K and 98% relative humidity, showing excellent proton conductivity.

[0066] Therefore, it can be said that the hydrogen-bonded organic framework nanosheets have good proton conduction performance and are an excellent proton conduction material.

[0067] The present invention is not limited to the specific technical solutions described in the above embodiments. Any technical solution formed by equivalent substitution is within the scope of protection required by the present invention.

Claims

1. A preparation method of hydrogen-bonded organic framework nanosheets based on amide compounds, characterized in that: It includes the following steps: (1) Dissolve amide compound C 27 H 21 N3O3 in dimethyl sulfoxide; the concentration of the dimethyl sulfoxide solution is 20 - 60 mmol / L; (2) By using the solvent phase transfer method, slowly diffuse the poor solvent into the solution obtained in step (1) to precipitate the target hydrogen-bonded organic framework crystals; (3) Ultrasonically exfoliate the crystals obtained in step (2), with water as the ultrasonic solvent, to obtain hydrogen-bonded organic framework nanosheets.

2. The preparation method of the hydrogen-bonded organic framework nanosheets based on amide compounds according to claim 1, wherein: The amide compound C in the step (1) 27 H 21 The preparation method of N3O3 is synthesized from 1,3,5-tris(4-methylphenyl)benzene, thionyl chloride, and ammonia water as raw materials.

3. The preparation method of the hydrogen-bonded organic framework nanosheets based on amide compounds according to claim 1, characterized in that: The preparation method of the amide compound C in the step (1) 27 H 21 N3O3 is as follows: Mix 2.0 g of 1,3,5-tris(4-methylphenyl)benzene, 6 mL of water and 3 mL of concentrated nitric acid in a polytetrafluoroethylene reaction kettle, and react at 170 o °C for 24 h. Then wash the product with water and recrystallize it with methanol to obtain 1,3,5-tris(4-carboxyphenyl)benzene. Subsequently, dissolve 1.0 g of 1,3,5-tris(4-carboxyphenyl)benzene in 30 mL of thionyl chloride, and simultaneously add a few drops of N,N-dimethylformamide as a catalyst. After reacting at 95 o °C for 12 h, remove the excess thionyl chloride, then add 150 mL of ammonia water, and react at room temperature for 24 h. Then filter out the product and recrystallize it with methanol to obtain the amide compound C 27 H 21 N3O3.

4. The preparation method of the hydrogen-bonded organic framework nanosheets based on amide compounds according to claim 1, characterized in that: The poor solvent in step (2) is tetrahydrofuran, the diffusion time is 3 - 5 days, and the volume ratio of the poor solvent to dimethyl sulfoxide in step (2) is 5:1 - 2:

1.

5. The preparation method of the hydrogen-bonded organic framework nanosheets based on amide compounds according to claim 1, characterized in that: The ultrasonic time in step (3) is 6 - 18 h.

6. Hydrogen-bonded organic framework nanosheets based on amide compounds prepared by any of the methods according to claims 1 - 5.

7. Use of the hydrogen-bonded organic framework nanosheets based on amide compounds according to claim 6, characterized in that: The hydrogen-bonded organic framework nanosheets based on amide compounds have excellent proton conductivity performance.

8. Use of the hydrogen-bonded organic framework nanosheets based on amide compounds according to claim 6, characterized in that: Drop-coat the dispersion of the hydrogen-bonded organic framework nanosheets on the surface of the interdigitated electrode and dry it naturally for testing its proton conductivity performance.

9. Use of the hydrogen-bonded organic framework nanosheets based on amide compounds according to claim 6, characterized in that: Applied to fuel cells, sensing and catalysis.

Images