A different flatness covalent organic framework material and preparation method and application thereof

Abstract

The present application relates to the technical field of porous polymer materials, and particularly relates to a covalent organic framework material with different flatness, a preparation method and application thereof. The method comprises the following steps: S10, preparing a first monomer through a coupling reaction; S20, mixing the first monomer, a second monomer, a catalyst and a solvent to perform a condensation reaction, so as to obtain the covalent organic framework material, wherein the condensation reaction is performed at a temperature of 60-180 DEG C, the first monomer comprises one or more of formulae 1-8, and the covalent organic framework material is purified; and S30, performing acidification or methylation treatment on the purified covalent organic framework material. Thus, the covalent organic framework material with different flatness prepared by the present application has a high conjugation degree, effectively enhances light absorption capacity, promotes separation and transfer of photo-generated carriers, and exhibits good light response characteristics and photocatalytic performance.

Description

Technical Field

[0001] This invention relates to the field of porous polymer materials technology, and in particular to a covalent organic framework material with different planarity, its preparation method and application. Background Technology

[0002] With the continuous growth of the global population and rapid industrialization, energy demand has exploded. The widespread use of traditional fossil fuels has not only exacerbated the depletion of fossil resources but also triggered ecological imbalances caused by global warming, severely impacting the sustainable development of the global economy. Therefore, exploring green, sustainable, and clean energy technologies has become a crucial issue for current social development. Against this backdrop, photocatalytic hydrogen production technology, as a green and environmentally friendly energy production method based on solar energy conversion, not only demonstrates unique advantages in environmental friendliness but also provides an important pathway to solving the energy crisis.

[0003] Covalent organic frameworks (COFrames) are a class of porous crystalline materials linked by covalent bonds. They possess highly tunable structures, abundant porosity, and high specific surface areas. Their excellent chemical stability, designability, and functionalization make them important for applications in gas storage, molecular screening, and photocatalysis. However, a major problem currently facing the photocatalytic application of COFrames is their poor ability to separate and transport photogenerated electrons and holes. The designability of the topological structure of COFrames greatly facilitates the optimization and improvement of their photocatalytic function. In particular, changes in the planarity of two-dimensional COFrames significantly affect the light absorption, separation, and transport of photogenerated electrons and holes during photocatalysis, directly determining the photocatalytic hydrogen production performance. Therefore, effectively controlling the planarity of COFrames using topological principles is of great significance for improving their photocatalytic hydrogen production performance.

[0004] Currently, research on the systematic regulation of the flatness of covalent organic framework materials is still insufficient. Therefore, the rational design of building blocks to regulate the flatness of covalent organic framework materials provides a new idea and method for their future photocatalytic development. Summary of the Invention

[0005] This application aims to address at least one of the technical problems existing in the prior art.

[0006] The first aspect of this application provides a method for preparing covalent organic framework materials with different planarity, comprising the following steps: S10: Prepare a first monomer via a coupling reaction, wherein the first monomer has one or more of the following structural formulas: ; Wherein: R includes one or more of the following: ; S20: The first monomer, the second monomer, the catalyst, and the solvent are mixed and subjected to a condensation reaction to obtain the covalent organic framework material. The temperature of the condensation reaction is 60℃-180℃. The first monomer includes one or more of Formulas 1-8. The covalent organic framework material is purified. S30: The purified covalent organic framework material is subjected to acidification or methylation treatment.

[0007] The method for preparing covalent organic framework materials proposed in this application allows for the adjustment of the framework planarity of the covalent organic framework material by selecting specific types of first and second monomers during the preparation process. Furthermore, post-processing improves the planarity of the connection sites between the first and second monomers, further increasing the overall planarity of the covalent organic framework material. On one hand, increased planarity can regulate the degree of π-conjugation in the framework, improving the visible light absorption capacity of the covalent organic framework material. On the other hand, the regulation of planarity can effectively improve the transport of π electrons within and between the framework layers of the covalent organic framework material, promoting the separation and transport of photogenerated electrons and holes, increasing carrier utilization, and thus improving the hydrogen production rate during photocatalysis.

[0008] According to some embodiments of this application, the first monomer includes one or more of 2,7,10,15-tetrasubstituted dibenzo[G,P], 2,5,8,11-tetrasubstituted perylene, 3,3',6,6'-tetrasubstituted-9,9'-difluorene, 3,3',6,6'-tetrasubstituted-9,9'-bicarbazole, tetra-(4-substituted phenyl)ethylene, 1,3,6,8-tetrasubstituted pyrene, 1,1,2,2-tetra(4-substituted phenyl)hydrazine, and 4,4',5,5'-tetrasubstituted tetrathiofulvalene.

[0009] According to some embodiments of this application, in step S10, the method for preparing the first monomer includes: performing a Suzuki reaction between a brominated central skeleton with different planarity and boric acid / pinacol ester monomers with different functional groups, wherein the boric acid / pinacol ester monomers with different functional groups include 4-formylphenylboronic acid / pinacol ester, 4-formyl-3-hydroxyphenylboronic acid, 4-formyl-3-fluorophenylboronic acid / pinacol ester, 4-formyl-3-methoxyphenylboronic acid, 4-formyl-3-hydroxyphenylboronic acid, 4-formyl-3-fluorophenylboronic acid / pinacol ester, 4-formyl-3-methoxyphenylboronic acid, 4-formyl-3-hydroxyphenylboronic acid, etc. - Trifluoromethylphenylboronic acid, 3-formyl-4-nitrophenylboronic acid, 4-formyl-3-methylphenylboronic acid, 3-carboxy-4-formylphenylboronic acid, 3-chloro-4-formylphenylboronic acid / pinacol borate ester, 2-fluoro-4-formylphenylboronic acid, 2-chloro-4-formylphenylboronic acid / pinacol borate ester, 4-formylchlorophenylboronic acid, 3-formylphenylboronic acid / pinacol borate ester, 3-formyl-4-hydroxyphenylboronic acid, 3-formyl-4-fluorophenylboronic acid / pinacol borate ester 3-Formyl-4-methoxyphenylboronic acid, 4-cyanomethylphenylboronic acid / pinacol borate ester, 4-aminophenylboronic acid / pinacol borate ester, 4-(hydrazine carbonyl)phenylboronic acid / pinacol borate ester, 5-aldehyde-2-thiopheneboronic acid / pinacol borate ester, (4-formylthiophene-2-yl)boronic acid / pinacol borate ester, 3-fluoro-4-aminophenylboronic acid / pinacol borate ester, 4-amino-3-hydroxyphenylboronic acid, 4-amino-3-methoxyphenylboronic acid / pinacol borate ester, 3-aminophenylboronic acid / One or more of the following are used in the Suzuki reaction: pinacol ester borate, 3-amino-4-chlorophenylboronic acid / pinacol ester borate, 3-amino-4-fluorophenylboronic acid / pinacol ester borate, 3-amino-4-methoxyphenylboronic acid / pinacol ester borate, and 3-amino-4-methylphenylboronic acid / pinacol ester borate. The molar ratio of the brominated central skeleton with different planarity and the boric acid / pinacol ester monomers with different functional groups is 1:(4.5-8.5). The reaction temperature is 90℃-120℃, and the reaction time is 48h-96h.

[0010] According to some embodiments of this application, in step S20, the second monomer includes one or more of 1,3,6,8-tetra(4-aminophenyl)pyrene, 1,3,6,8-tetra(4-carboxyphenyl)pyrene, 5,5',5'',5'''-(pyrene-1,3,6,8-tetrayl)tetra(pyridine-2-carboxaldehyde), p-phenylenediamine, 4,4'-biphenyldicarboxaldehyde, 2,6-naphthalenedialdehyde, and terephthalonitrile.

[0011] According to some embodiments of this application, in step S20, the molar ratio of the first monomer to the second monomer is 1:(0.1-1.5).

[0012] According to some embodiments of this application, in step S20, the solvent includes one or more of 1,4-dioxane, mesitylene, o-dichlorobenzene, n-butanol, N,N-dimethylformamide, benzyl alcohol, anisole, and N-methylpyrrolidone.

[0013] According to some embodiments of this application, the catalyst in step S20 includes one or more of acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, sodium hydroxide, potassium hydroxide, and tetrahydropyrrole.

[0014] According to some embodiments of this application, in step S30, the acidification treatment includes: reacting the covalent organic framework material in an acid solution at 25°C-100°C for 0.5h-96h, wherein the acid solution includes one or more of the following: 0.02mol / L-1.0mol / L hydrochloric acid solution, acetic acid solution, benzoic acid solution, sulfuric acid solution, nitric acid solution, and phosphoric acid solution; and / or The methylation treatment includes: uniformly dispersing the covalent organic framework material and iodomethane in a molar ratio of 1:(4-5) in one or more solutions of acetonitrile, N,N-dimethylformamide, and tetrahydrofuran, and stirring at room temperature for 0.5h-72h.

[0015] The second aspect of this application provides a covalent organic framework material prepared by the method provided in the first aspect of this application.

[0016] The third aspect of this application provides the application of the covalent organic framework materials provided in the second aspect of this application in catalytic synthesis.

[0017] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0018] The advantages of the above and / or additional aspects of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic flowchart of a preparation method according to an embodiment of this application.

[0019] Figure 2 This is a schematic diagram of the structures of four aldehyde monomers with different planarity prepared in Example 1 of this application and the spirodiol monomer of Comparative Example 1.

[0020] Figure 3 This is a schematic diagram of the structure of the covalent organic framework material prepared in Example 1 of this application and the covalent organic framework material prepared in Comparative Example 1.

[0021] Figure 4This refers to the flatness of the three covalent organic framework materials in Embodiment 1 of this application.

[0022] Figure 5 This is the powder X-ray diffraction pattern and theoretical simulation diagram of BFTB-Py COF prepared in Example 1 of this application.

[0023] Figure 6 These are the powder X-ray diffraction patterns of BFTB-Py COF, BCTB-Py COF, and TPEB-Py COF prepared in Example 1 of this application, 3F-BFTB-Py COF prepared in Example 2, BCTB-PD COF prepared in Example 3, TZ-BCTB-Py COF prepared in Example 4, and sp2-c COF and BCTB-PDAN COF prepared in Example 5.

[0024] Figure 7 This is the powder X-ray diffraction pattern of Comparative Example 1.

[0025] Figure 8 These are the Fourier transform infrared absorption spectra of the BFTB-Py COF prepared in Example 1 of this application before and after protonation.

[0026] Figure 9 This is the Fourier transform infrared absorption spectrum of Comparative Example 1.

[0027] Figure 10 These are the UV-Vis diffuse reflectance spectra of BFTB-Py COF and TPHB-Py COF prepared in Example 1 of this application before and after protonation, as well as the UV-Vis diffuse reflectance spectrum of TPAL-SBF COF prepared in Comparative Example 1.

[0028] Figure 11 The BFTB-Py COF prepared in Example 1, the BCTB-PD COF prepared in Example 3, and the sp prepared in Example 5 of this application are all examples of the COF prepared in this application. 2 SEM image with -c COF.

[0029] Figure 12 These are contact angle test images of the BFTB-Py COF prepared in Example 1 of this application before and after protonation.

[0030] Figure 13 The fluorescence spectra (PL) of BFTB-Py COF and TPHB-Py COF prepared in Example 1 of this application are measured.

[0031] Figure 14 This is a photocurrent test of the covalent organic framework material prepared in Example 1 of this application.

[0032] Figure 15This is a comparison chart of photocatalytic hydrogen production under optimal conditions in Example 1 and Comparative Example 1 of this application. Detailed Implementation

[0033] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0034] The first aspect of this application provides a method for preparing covalent organic framework materials with different planarity, comprising the following steps: S10: Prepare a first monomer via a coupling reaction, wherein the first monomer has one or more of the following structural formulas: ; Wherein: R includes one or more of the following: ; S20: The first monomer, the second monomer, the catalyst, and the solvent are mixed and subjected to a condensation reaction to obtain the covalent organic framework material. The temperature of the condensation reaction is 60℃-180℃. The first monomer includes one or more of Formula 1-8. The covalent organic framework material is purified. S30: The purified covalent organic framework material is acidified or methylated.

[0035] The method for preparing covalent organic framework materials proposed in this application allows for the adjustment of the framework planarity of the covalent organic framework material by selecting specific types of first and second monomers during the preparation process. Furthermore, post-processing improves the planarity of the connection sites between the first and second monomers, further increasing the overall planarity of the covalent organic framework material. On one hand, increased planarity can regulate the degree of π-conjugation in the framework, improving the visible light absorption capacity of the covalent organic framework material. On the other hand, the regulation of planarity can effectively improve the transport of π electrons within and between layers of the covalent organic framework framework, promoting the separation and transport of photogenerated electrons and holes, increasing carrier utilization, and thus improving the hydrogen production rate during photocatalysis.

[0036] The following provides a detailed description of each step of the method proposed in this application, with reference to... Figure 1 The method includes: S10: Preparation of the first monomer via a coupling reaction According to some embodiments of this application, in step S10, the method for preparing the first monomer includes: mixing a brominated central skeleton with different planarity with boric acid / pinacol borate monomers with different functional groups, a catalyst, and a solvent, and carrying out a Suzuki reaction. The boric acid / pinacol borate monomers with different functional groups include 4-formylphenylboronic acid / pinacol borate, 4-formyl-3-hydroxyphenylboronic acid, 4-formyl-3-fluorophenylboronic acid / pinacol borate, 4-formyl-3-methoxyphenylboronic acid, and 4- Formyl-3-trifluoromethylphenylboronic acid, 3-formyl-4-nitrophenylboronic acid, 4-formyl-3-methylphenylboronic acid, 3-carboxy-4-formylphenylboronic acid, 3-chloro-4-formylphenylboronic acid / pinacol borate ester, 2-fluoro-4-formylphenylboronic acid, 2-chloro-4-formylphenylboronic acid / pinacol borate ester, 4-formylchlorophenylboronic acid, 3-formylphenylboronic acid / pinacol borate ester, 3-formyl-4-hydroxyphenylboronic acid, 3-formyl-4-fluorophenylboronic acid / pinacol borate ester, 3 -Formyl-4-methoxyphenylboronic acid, 4-cyanomethylphenylboronic acid / pinacol borate, 4-aminophenylboronic acid / pinacol borate, 4-(hydrazine carbonyl)phenylboronic acid / pinacol borate, 5-aldehyde-2-thiopheneboronic acid / pinacol borate, (4-formylthiophene-2-yl)boronic acid / pinacol borate, 3-fluoro-4-aminophenylboronic acid / pinacol borate, 4-amino-3-hydroxyphenylboronic acid, 4-amino-3-methoxyphenylboronic acid / pinacol borate, 3-aminophenylboronic acid / pinacol borate One or more of 3-amino-4-chlorophenylboronic acid / pinacol borate, 3-amino-4-fluorophenylboronic acid / pinacol borate, 3-amino-4-methoxyphenylboronic acid / pinacol borate, and 3-amino-4-methylphenylboronic acid / pinacol borate are used in the Suzuki reaction. The molar ratio of the brominated central skeleton with different planarity and the boric acid / pinacol borate monomers with different functional groups is 1:(4.5-8.5). The reaction temperature is 90℃-120℃ and the reaction time is 48h-96h.

[0037] Specifically, the brominated central skeleton is mixed with boric acid / boranoic acid pinacol ester monomer, catalyst, and solvent in a reactor and refluxed under inert gas protection. After the reactants have completely reacted, the reaction solution is cooled to room temperature and introduced into ice water to precipitate the precipitate. The precipitate is washed and dried to obtain the first monomer.

[0038] As an example, the molar ratio of the brominated central skeleton with different planarity and the boric acid / pinacol ester monomers with different functional groups in the Suzuki reaction process can be 1:4.5, 1:5.5, 1:6.5, 1:7.5, 1:8.5, or any range of the above values. Therefore, the prepared first monomer has high purity and is easy to purify.

[0039] As an example, the reaction temperature during the Suzuki reaction can be 90℃, 95℃, 100℃, 105℃, 110℃, 115℃, 120℃, or any range of the above values. This ensures complete reaction of the reactants, high product yield and purity, and ease of purification.

[0040] As an example, the Suzuki reaction time can be 48 h, 58 h, 68 h, 78 h, 96 h, or any range of the above values. This allows the reactants to participate in the reaction as much as possible, reducing the occurrence of side reactions.

[0041] According to some embodiments of this application, the first monomer includes one or more of 2,5,8,11-tetrasubstituted perylene, 2,7,10,15-tetrasubstituted dibenzo[G,P], 3,3',6,6'-tetrasubstituted-9,9'-difluorene, 3,3',6,6'-tetrasubstituted-9,9'-bicarbazole, tetra-(4-substituted phenyl)ethylene, 1,3,6,8-tetrasubstituted pyrene, 1,1,2,2-tetra(4-substituted phenyl)hydrazine, and 4,4',5,5'-tetrasubstituted tetrathiofulvalene.

[0042] According to some embodiments of this application, the catalyst used in preparing the first monomer includes one or more of tetraphenylphosphine palladium and 1,1'-bis(diphenylphosphine)ferrocene palladium dichloride.

[0043] According to some embodiments of this application, the solvent used to prepare the first monomer includes one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), 1,4-dioxane, toluene, and tetrahydrofuran.

[0044] According to some embodiments of this application, the 4,4',5,5'-tetrasubstituted tetrathiofulvalene monomer is synthesized by further reacting tetrathiofulvalene with 4-bromobenzaldehyde, 4-bromoaniline, 4-bromo-2-fluorobenzaldehyde, 4-bromo-3-fluorobenzaldehyde, 4-bromo-2-methoxybenzaldehyde, 4-bromo-2-methylbenzaldehyde, 4-bromo-2-chlorobenzaldehyde, 4-bromo-3-chlorobenzaldehyde, 3-bromobenzaldehyde, 4-bromo-3-chlorobenzaldehyde, 4-bromo-3-fluorobenzaldehyde, and 4-bromo-2-hydroxybenzaldehyde via a Heck reaction. During the reaction, the molar ratio of tetrathiofulvalene, 4-bromine monomers with different functional groups, Pd(OAc)2, P(t-Bu)3·HBF and cesium carbonate is 1:(7-9):(0.2-0.4):0.75:(1.5-1.7), the reaction temperature is 60℃-80℃, and the reaction solvent is one or more of tetrahydrofuran, toluene, and 1,4-dioxane.

[0045] S20: The first monomer, the second monomer, the catalyst, and the solvent are mixed and subjected to a condensation reaction to obtain the covalent organic framework material. In this step, the first monomer, the second monomer, the catalyst, and the solvent are mixed to carry out a [4+4] or [4+2] condensation reaction.

[0046] According to some embodiments of this application, the temperature of the condensation reaction is 60℃-180℃, for example, it can be 60℃, 80℃, 100℃, 120℃, 140℃, 160℃, 180℃, etc., or it can be any range of the above values.

[0047] According to some embodiments of this application, the first monomer includes one or more of Formulas 1-8.

[0048] According to some embodiments of this application, the second monomer includes one or more of 1,3,6,8-tetra(4-aminophenyl)pyrene, 1,3,6,8-tetra(4-carboxyphenyl)pyrene, 5,5',5'',5'''-(pyrene-1,3,6,8-tetrayl)tetra(pyridine-2-carboxaldehyde), p-phenylenediamine, 4,4'-biphenyldicarboxaldehyde, 2,6-naphthalenedialdehyde, and terephthalonitrile.

[0049] According to some embodiments of this application, the molar ratio of the first monomer to the second monomer is 1:(0.1-1.5). Therefore, the prepared covalent organic framework exhibits high crystallinity and fewer defects.

[0050] As an example, the molar ratio of the first monomer to the second monomer can be 1:0.1, 1:0.3, 1:0.5, 1:0.7, 1:0.9, 1:1.1, 1:1.5, or any range of the above values. Therefore, covalent organic frameworks with different structures and morphologies can be prepared.

[0051] According to some embodiments of this application, the solvent in step S20 includes one or more of 1,4-dioxane, mesitylene, o-dichlorobenzene, n-butanol, N,N-dimethylformamide, benzyl alcohol, anisole, and N-methylpyrrolidone. This sufficiently promotes the reaction between the two types of monomers, facilitating the formation of a covalent organic framework.

[0052] According to some embodiments of this application, the catalyst in step S20 includes one or more of acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, sodium hydroxide, potassium hydroxide, and tetrahydropyrrole. This accelerates the reaction between the two types of monomers and promotes the formation of a covalent organic framework.

[0053] S30: Acidification or methylation treatment of the purified covalent organic framework material. According to some embodiments of this application, the acidification treatment includes: reacting the covalent organic framework material in an acid solution at 25℃-100℃ for 0.5h-96h, wherein the acid solution includes one or more of hydrochloric acid solution, acetic acid solution, benzoic acid solution, sulfuric acid solution, nitric acid solution, and phosphoric acid solution at a concentration of 0.02mol / L-1.0mol / L, to further improve the planarity of the framework.

[0054] In some embodiments of this application, the methylation treatment includes: uniformly dispersing the covalent organic framework material and iodomethane in a molar ratio of 1:(4-5) in one or more solutions of acetonitrile, N,N-dimethylformamide, and tetrahydrofuran, and stirring at room temperature for 0.5h-72h, thereby methylating the imine bonds to change the planarity of the framework.

[0055] The second aspect of this application proposes a covalent organic framework material with different planarity and functional groups, which is prepared using the method proposed in the first aspect of this application.

[0056] The third aspect of this application discloses the application of covalent organic framework materials with different planarity prepared by the method proposed in the first aspect of this application, or covalent organic framework materials with different planarity proposed in the second aspect of this application, in the field of photocatalysis.

[0057] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Example 1

[0058] Preparation of 1,3,6,8-tetra(4-aminophenyl)pyrene (Py-4NH2) monomer In a 100 mL round-bottom flask, 1,3,6,8-tetrabromopyrene (2.0 g, 3.8 mmol), pinacol tetraaminophenylboronic acid (5.98 g, 23.56 mmol), tetra(triphenylphosphine)palladium (335 mg, 0.290 mmol), potassium carbonate (2.17 g, 15.7 mmol), 1,4-dioxane (50 mL), and water (10 mL) were added. The reaction mixture was refluxed under nitrogen protection for 48 hours. After the reactants had completely reacted, the reaction solution was cooled to room temperature and poured into ice water to precipitate a yellow precipitate. The precipitate was collected by suction filtration, washed repeatedly with water and methanol, and dried to obtain the product (70% yield).

[0059] Preparation of 4,4',4'',4''-([9,9'-fluorenylbiphenyl]-3,3',6,6'-tetramethyl)tetrabenzaldehyde (BFTB-4CHO) monomer 3,3',6,6'-Tetrabromo-9,9'-difluorene alkylene (2.0 g, 3.10 mmol), 4-formylphenylboronic acid (3.72 g, 24.8 mmol), potassium carbonate (4.30 g, 31.10 mmol), tetra(triphenylphosphine)palladium (180 mg, 0.154 mmol), ultradry 1,4-dioxane (100 mL), and deionized water (20 mL) were added to a 250 mL round-bottom flask and thoroughly dispersed by sonication. The mixture was heated to 97 °C and refluxed for 72 hours under nitrogen protection. After the reaction was completed, the mixture was cooled to room temperature, and the red precipitate was collected by vacuum filtration. The precipitate was washed repeatedly with water, methanol, and dichloromethane. The product was then refluxed in tetrahydrofuran for 2 hours and filtered to obtain a red powder, BFTB-4CHO (1.86 g, 80% yield). Due to the limited solubility of BFTB-4CHO in common organic solvents, only 1H NMR data are provided. 1 H NMR (600 MHz, DMSO-d6, ppm): δ = 10.10 (s, 4H), 8.65 (s, 4H), 8.43 (d,4H), 8.14 (d, 4H), 8.08 (d, 4H), 7.78 (d, 4H).

[0060] Preparation of BFTB-Py COF: Weigh 55.203 mg (0.074 mmol) of 4,4',4'',4''-([9,9'-fluorenylbiphenyl]-3,3',6,6'-tetramethyl)tetrabenzaldehyde (BFTB-4CHO) and 42 mg (0.074 mmol) of 1,3,6,8-tetra(4-methylaminophenyl)pyrene (Py-4NH2), place them in a high-temperature and high-pressure resistant thick-walled glass tube, add 2 mL of a mixed solvent of o-dichlorobenzene and 2 mL of n-butanol, sonicate for 10 min to form a homogeneous suspension, then add 0.56 mL of 6 mol / L acetic acid solution and sonicate for 5 min. After three cycles of freezing-vacuum-thawing, seal the tube and react at 120 °C for 72 h. After the reaction, the material was repeatedly washed with ethanol and DMF, then extracted with tetrahydrofuran using a Soxhlet extractor for 24 hours, and finally dried in a vacuum oven at 100°C for 24 hours to obtain BFTB-Py COF material. The BFTB-Py COF material was ultrasonically dispersed in a prepared 0.2M HCl solution for acidification, allowed to stand for 30 minutes, centrifuged, and dried under vacuum at 100°C for 24 hours to obtain BFTB-Py COF material with further improved skeleton planarity.

[0061] Preparation of 4,4',4'',4'''-([9,9'-bicarbazole]-3,3',6,6'-tetramethyl)tetrabenzaldehyde (BCTB-4CHO) monomer To a 150 mL round-bottom flask, 3,3',6,6'-tetrabromo-9,9'-bicarbazole (1.85 g, 2.86 mmol), 4-aminophenylboronic acid (3.01 g, 13.7 mmol), tetra(triphenylphosphine)palladium (335 mg, 0.290 mmol), potassium carbonate (2.17 g, 15.7 mmol), ultra-dry 1,4-dioxane (40 mL), and deionized water (8 mL) were added sequentially. The mixture was sonicated until homogeneous and then refluxed under argon atmosphere for 72 hours. After the reaction was complete, the solution was poured into a 100 mL ice-water mixture, stirred, and filtered. The solution was washed repeatedly with water, methanol, and dichloromethane to obtain a creamy-white product (1.92 g, 90% yield). 1 H NMR (600 MHz, DMSO-) d 6, ppm): δ = 8.31 (d, 4H), 8.15 (d, 4H), 7.51 (dd, 4H).

[0062] Preparation of BCTB-Py COF: The preparation method of BCTB-Py COF is the same as that of BFTB-Py COF in Example 1, except that 4,4',4'',4'''-([9,9'-bicarbazol]-3,3',6,6'-tetramethyl)tetrabenzaldehyde (55.566 mg, 0.074 mmol) and 1,3,6,8-tetra(4-methylaminophenyl)pyrene (Py-4NH2) (42 mg, 0.074 mmol) are added to a thick-walled glass tube.

[0063] Preparation of tetra-(4-aldehyde-(1,1-biphenyl))ethylene (TPEB-4CHO) monomer: Prepare a 150 mL round-bottom flask and add tetra-(4-bromophenyl)ethylene (1.85 g, 2.86 mmol), 4-aminophenylboronic acid (3.01 g, 13.7 mmol), tetra(triphenylphosphine)palladium (335 mg, 0.290 mmol), potassium carbonate (2.17 g, 15.7 mmol), dioxane (50 mL), and water (10 mL). Reflux under nitrogen atmosphere for 72 hours. After the reaction is complete, add 120 mL of deionized water, stir, and filter the precipitate. Wash 3-4 times with deionized water and methanol to obtain TPEB-4CHO (1.88 g, 88% yield). 1 H NMR (600 MHz, DMSO-) d 6, ppm): δ = 10.03 (s, 4H), 7.95 (s, 8H), 7.90 (s, 8H), 7.68 (s, 8H), 7.23 (s, 8H).

[0064] Preparation of TPEB-Py COF: The preparation method of TPEB-Py COF is the same as that of BFTB-Py COF in Example 1, except that tetra-(4-aldehyde-(1,1-biphenyl))ethylene (55.571 mg, 0.074 mmol) and 1,3,6,8-tetra(4-methylaminophenyl)pyrene (Py-4NH2) (42 mg, 0.074 mmol) are added to a thick-walled glass tube.

[0065] Preparation of TPHB-Py COF: 4',4''',4'''',4'''''''-(hydrazine-1,1,2,2-tetramethyl)tetra(([1,1'-biphenyl]-4-carboxaldehyde)) (55.867 mg, 0.074 mmol) and 1,3,6,8-tetra(4-aminophenyl)pyrene (Py-4NH2) (42 mg, 0.074 mmol) were added to a thick-walled glass tube, followed by 2 mL of a mixed solvent of o-dichlorobenzene and 2 mL of n-butanol. The mixture was sonicated for 10 min to form a homogeneous suspension, and then 0.56 mL of 6 mol / L acetic acid solution was added and sonicated for 5 min. After three cycles of freezing-vacuum-thawing, the tube was sealed and reacted at 120 °C for 72 h. After the reaction, the tube was repeatedly washed with ethanol and DMF, then extracted with tetrahydrofuran using a Soxhlet extractor for 24 h, and finally dried in a vacuum oven at 100 °C for 24 h to obtain the TPHB-Py COF material. Example 2

[0066] Preparation of 3F-BFTB-Py COF: The preparation method of 3F-BFTB-Py COF is the same as that of BFTB-Py COF in Example 1, except that 4,4',4'',4'''-([9,9'-bisfluoreneene]-3,3',6,6'-tetraene)tetra(2-fluorobenzaldehyde) (60.680 mg, 0.074 mmol) and 1,3,6,8-tetra(4-methylaminophenyl)pyrene (Py-4NH2) (42 mg, 0.074 mmol) are added to a thick-walled glass tube.

[0067] Preparation of 3F-BCTB-Py COF: The preparation method of 3F-BCTB-Py COF is the same as that of BFTB-Py COF in Example 1, except that 4,4',4''',4''''-([9,9'-biscarbazole]-3,3',6,6'-tetraene)tetra(2-fluorobenzaldehyde) (60.444 mg, 0.074 mmol) and 1,3,6,8-tetra(4-methylaminophenyl)pyrene (Py-4NH2) (42 mg, 0.074 mmol) are added to a thick-walled glass tube. Example 3

[0068] Preparation of BCTB-PD COF: The preparation method of BCTB-PD COF is the same as that of BFTB-Py COF in Example 1, except that 4,4',4'',4'''-([9,9'-bicarbazol]-3,3',6,6'-tetramethyl)tetrabenzaldehyde (55.566 mg, 0.074 mmol) and p-phenylenediamine (PD) (16.049 mg, 0.148 mmol) are added to a thick-walled glass tube.

[0069] Preparation of TPEB-PD COF: The preparation method of TPEB-PD COF is the same as that of BFTB-Py COF in Example 1, except that tetra-(4-aldehyde-(1,1-biphenyl))ethylene (55.571 mg, 0.074 mmol) and p-phenylenediamine (PD) (16.049 mg, 0.148 mmol) are added to a thick-walled glass tube. Example 4

[0070] Preparation of TZ-BCTB-Py COF: The preparation method of TZ-BCTB-Py COF is the same as that of BFTB-Py COF in Example 1, except that 4,4',4'',4'''-([9,9'-bicarbazol]-3,3',6,6'-tetramethyl)tetrabenzaldehyde (55.566 mg, 0.074 mmol), p-phenylenediamine (PD) (16.049 mg, 0.148 mmol), and elemental sulfur (2.368 mg, 0.074 mmol) are added to a thick-walled glass tube. Then, 1.9 mL of o-dichlorobenzene, 1.9 mL of n-butanol, 0.2 mL of DMSO, and 0.56 mL of 4M acetic acid solution are added to the system.

[0071] Preparation of TZ-TPEB-Py COF: The preparation method of TZ-TPEB-Py COF is the same as that of BFTB-Py COF in Example 1, except that tetra-(4-aldehyde-(1,1-biphenyl))ethylene (55.571 mg, 0.074 mmol) and p-phenylenediamine (PD) (16.049 mg, 0.148 mmol) are added to a thick-walled glass tube. Example 5

[0072] sp 2 Preparation of -c COF: sp 2The preparation method of -c COF is the same as that of BFTB-Py COF in Example 1, except that 1,3,6,8-tetrakis(4-carboxylphenyl)pyrene (29.70 mg, 0.048 mmol) and terephthalonitrile (PDAN) (14.68 mg, 0.086 mmol) are added to a thick-walled glass tube, followed by the addition of 2 mL of dioxane and 0.25 mL of 4M NaOH solution to the system.

[0073] The preparation method of BCTB-PDAN COF is the same as that of BFTB-Py COF in Example 1, except that 4,4',4'',4'''-([9,9'-bicarbazol]-3,3',6,6'-tetramethyl)tetrabenzaldehyde (36.043 mg, 0.048 mmol) and terephthalonitrile (PDAN) (14.68 mg, 0.086 mmol) are added to a thick-walled glass tube, followed by the addition of 2 mL of dioxane and 0.25 mL of 4M NaOH solution.

[0074] The preparation method of TPEB-PDAN COF is the same as that of BFTB-Py COF in Example 1, except that tetra-(4-aldehyde-(1,1-biphenyl))ethylene (36.046 mg, 0.048 mmol) and terephthalonitrile (PDAN) (14.68 mg, 0.086 mmol) are added to a thick-walled glass tube, followed by the addition of 2 mL of dioxane and 0.25 mL of 4M NaOH solution to the system. Comparative Example 1

[0075] Preparation of TPAL-SBF COF: Terephthalaldehyde (TPAL) (12.899 mg, 0.096 mmol) and 4,4',4'',4'''-([9,9'-spirodifluorene-2,2',7,7'-tetrayl]tetra(phenyl-4,1-diyl))tetraphenylamine (SBF-4NH2) (33.015 mg, 0.048 mmol) were placed in a high-temperature and high-pressure resistant thick-walled glass tube. A mixed solvent of o-dichlorobenzene and n-butanol was added, and the mixture was sonicated for 10 min to form a homogeneous suspension. Then, 0.56 mL of 6 mol / L acetic acid solution was added, and the mixture was sonicated for 5 min. After three cycles of freezing-vacuum-thawing, the tube was sealed and reacted at 120 °C for 72 h. After the reaction, the tube was repeatedly washed with ethanol, DMF, and methanol, then extracted with tetrahydrofuran using a Soxhlet extractor for 24 h, and finally dried in a vacuum oven at 100 °C for 24 h to obtain the TPAL-SBF COF material.

[0076] Powder X-ray diffraction (PXRD) was performed under the following conditions: Cu-Ka as the radiation source, 40 kV voltage, 20 mA current, 0.05° step size, and 5° / min scanning speed, covering a range of 2θ = 2 - 50°. All covalent organic framework materials were ground into powder using an agate mortar before testing.

[0077] Fourier transform infrared absorption spectroscopy (FT-IR): FT-IR measurements were recorded using a KBr disk on a Bruker INVENIO S, with a measurement range of 1000 cm⁻¹. -1 -4000cm -1 .

[0078] Ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS): Performed on a PerkinElmer Lambda 850+ series UV-Vis spectrophotometer, using BaSO4 as a control, with a test range of 250nm-800nm.

[0079] Scanning Electron Microscopy (SEM): SEM testing is performed on a 7900F field emission scanning electron microscope from Nippon Electron. The sample dispersion droplets are sputtered onto a silicon wafer and then tested.

[0080] Contact angle test: The contact angle is tested on the LAUDA Scientific LSA100 contact angle measuring instrument in Germany. The sample powder needs to be pressed flat using a tablet press, and the measurement is performed using the seat drop method.

[0081] Photoluminescence spectroscopy (PL): PL spectra were measured on a steady-state / transient fluorescence spectrometer of the FLS980 series in Edinburgh, UK, with an excitation wavelength of 350 nm.

[0082] Photocurrent testing (it): Performed on a CHI 760E electrochemical workstation using a standard three-electrode system. A Pt sheet (1cm*1cm) was used as the counter electrode, Ag / AgCl as the reference electrode, and a covalent organic framework material coated on ITO glass was used as the working electrode. The electrolyte was a 0.5M Na2SO4 aqueous solution. The working electrode was irradiated with a xenon lamp, and the test was performed with multiple on / off lamp cycles.

[0083] Photocatalytic hydrogen production performance testing (HER): The test was conducted using a Pfile all-glass automated online trace gas analysis system (LabSolar 6A) coupled with a Fuli gas chromatograph (GC9790II). The specific procedure is as follows: 2 mg of covalent organic framework material and 3.52 g of ascorbic acid were added to 100 ml of deionized water as sacrificial agents and sonicated for 10 minutes to disperse them evenly. Then, 20 μl of chloroplatinic acid solution with a concentration of 4 mg / mL was added to load Pt onto the covalent organic framework material via photodeposition. Using LabSolar 6A as the reaction system, after thorough evacuation, 20 mL of argon gas was added as the carrier gas. The temperature of the catalytic testing system was controlled at 5 °C, a xenon lamp was used as a simulated light source, and the photocatalytic gas was detected using a gas chromatograph.

[0084] Depend on Figure 3 It can be seen that the covalent organic framework materials prepared in Example 1 and Comparative Example 1 of this application have similar topological structures.

[0085] Depend on Figure 4 It can be seen that the covalent organic framework materials prepared in Example 1 of this application have different flatness.

[0086] Depend on Figure 5 It can be seen that the BFTB-Py COF prepared in Example 1 of this application has good crystallinity.

[0087] Depend on Figure 6 It can be seen that the covalent organic framework materials prepared in Example 1 of this application have similar crystal structures. The 3F-BFTB-Py COF prepared in Example 2, the BCTB-PD COF prepared in Example 3, the TZ-BCTB-PyCOF prepared in Example 4, and the sp prepared in Example 5 are also similar. 2 Both -c COF and BCTB-PDAN COF exhibit good crystallinity.

[0088] Depend on Figure 7 It can be seen that the covalent organic framework material prepared in Comparative Example 1 of this application has low planarity and poor crystallinity.

[0089] Depend on Figure 8 It can be seen that the BFTB-Py COF prepared in Example 1 of this application was successfully synthesized and successfully protonated.

[0090] Depend on Figure 9 It can be seen that the TPAL-SBF COF prepared in the comparative example of this application was successfully synthesized.

[0091] Depend on Figure 10It can be seen that the BFTB-Py COF and TPHB-Py COF prepared in Example 1 of this application have different light absorption ranges, and the light absorption range is red-shifted after protonation; the TPAL-SBF COF prepared in Comparative Example 1 of this application has a narrow light absorption range due to its low flatness.

[0092] Depend on Figure 11 It can be seen that the BFTB-Py COF prepared in Example 1, the BCTB-PDCOF prepared in Example 3, and the sp prepared in Example 5 of this application are all superior. 2 -c COF has different morphological structures.

[0093] Depend on Figure 12 It can be seen that the hydrophilicity of the BFTB-Py COF prepared in Example 1 of this application is significantly improved after protonation.

[0094] Depend on Figure 13 It can be seen that the BFTB-Py COF and TPHB-Py COF prepared in Example 1 of this application have different fluorescence signals. The BFTB-Py COF signal is weaker, indicating that it has faster charge transport.

[0095] Depend on Figure 14 It can be seen that the covalent organic frameworks prepared in Example 1 of this application exhibit different photocurrent responses, demonstrating different photogenerated electron-hole separation and transfer capabilities.

[0096] Depend on Figure 15 It can be seen that the photocatalytic hydrogen production performance of the covalent organic framework material prepared in Example 1 under optimal conditions is better than that of Comparative Example 1, indicating that the catalyst planarity control in this application can effectively control its photocatalytic hydrogen production performance.

[0097] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for preparing covalent organic framework materials with different planarity, characterized in that, Includes the following steps: S10: Prepare a first monomer via a coupling reaction, wherein the first monomer has one or more of the following structural formulas: ； Wherein: R includes one or more of the following: ； S20: The first monomer, the second monomer, the catalyst, and the solvent are mixed and subjected to a condensation reaction to obtain the covalent organic framework material. The temperature of the condensation reaction is 60℃-180℃. The first monomer includes one or more of Formula 1-8. The covalent organic framework material is purified. S30: The purified covalent organic framework material is subjected to acidification or methylation treatment.

2. The method according to claim 1, characterized in that, The first monomer comprises one or more of the following: 2,7,10,15-tetrasubstituted dibenzo[G,P], 2,5,8,11-tetrasubstituted perylene, 3,3',6,6'-tetrasubstituted-9,9'-difluorene, 3,3',6,6'-tetrasubstituted-9,9'-bicarbazole, tetra-(4-substituted phenyl)ethylene, 1,3,6,8-tetrasubstituted pyrene, 1,1,2,2-tetra(4-substituted phenyl)hydrazine, and 4,4',5,5'-tetrasubstituted tetrathiofulvalene.

3. The method according to claim 1, characterized in that, In step S10, the method for preparing the first monomer includes: performing a Suzuki reaction on a brominated central skeleton with different planarity and boric acid / pinacol ester monomers with different functional groups, wherein the boric acid / pinacol ester monomers with different functional groups include 4-formylphenylboronic acid / pinacol ester, 4-formyl-3-hydroxyphenylboronic acid, 4-formyl-3-fluorophenylboronic acid / pinacol ester, 4-formyl-3-methoxyphenylboronic acid, and 4-formyl-3-trifluorophenylboronic acid. Methylphenylboronic acid, 3-formyl-4-nitrophenylboronic acid, 4-formyl-3-methylphenylboronic acid, 3-carboxy-4-formylphenylboronic acid, 3-chloro-4-formylphenylboronic acid / pinacol borate ester, 2-fluoro-4-formylphenylboronic acid, 2-chloro-4-formylphenylboronic acid / pinacol borate ester, 4-formylchlorophenylboronic acid, 3-formylphenylboronic acid / pinacol borate ester, 3-formyl-4-hydroxyphenylboronic acid, 3-formyl-4-fluorophenylboronic acid / boron Pinacol ester, 3-formyl-4-methoxyphenylboronic acid, 4-cyanomethylphenylboronic acid / pinacol borate ester, 4-aminophenylboronic acid / pinacol borate ester, 4-(hydrazine carbonyl)phenylboronic acid / pinacol borate ester, 5-aldehyde-2-thiopheneboronic acid / pinacol borate ester, (4-formylthiophene-2-yl)boronic acid / pinacol borate ester, 3-fluoro-4-aminophenylboronic acid / pinacol borate ester, 4-amino-3-hydroxyphenylboronic acid, 4-amino-3-methoxyphenyl One or more of the following are used in the Suzuki reaction: pinacol ester borate, 3-aminophenylboronic acid / pinacol ester borate, 3-amino-4-chlorophenylboronic acid / pinacol ester borate, 3-amino-4-fluorophenylboronic acid / pinacol ester borate, 3-amino-4-methoxyphenylboronic acid / pinacol ester borate, and 3-amino-4-methylphenylboronic acid / pinacol ester borate. The molar ratio of the brominated central skeleton with different planarity and the boric acid / pinacol ester borate monomers with different functional groups is 1:(4.5-8.5). The reaction temperature is 90℃-120℃, and the reaction time is 48h-96h.

4. The method according to any one of claims 1-3, characterized in that, In step S20, the second monomer includes one or more of 1,3,6,8-tetra(4-aminophenyl)pyrene, 1,3,6,8-tetra(4-carboxyphenyl)pyrene, 5,5',5'',5'''-(pyrene-1,3,6,8-tetrayl)tetra(pyridine-2-carboxaldehyde), p-phenylenediamine, 4,4'-biphenyldicarboxaldehyde, 2,6-naphthalenedialdehyde, and terephthalonitrile.

5. The method according to any one of claims 1-3, characterized in that, In step S20, the molar ratio of the first monomer to the second monomer is 1:(0.1-1.5).

6. The method according to any one of claims 1-3, characterized in that, In step S20, the solvent includes one or more of 1,4-dioxane, mesitylene, o-dichlorobenzene, n-butanol, N,N-dimethylformamide, benzyl alcohol, anisole, and N-methylpyrrolidone.

7. The method according to any one of claims 1-3, characterized in that, In step S20, the catalyst includes one or more of acetic acid, trifluoroacetic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid, sodium hydroxide, potassium hydroxide, and tetrahydropyrrole.

8. The method according to any one of claims 1-3, characterized in that, In step S30, the acidification treatment includes: The covalent organic framework material is reacted in an acidic solution at 25°C-100°C for 0.5h-96h, wherein the acidic solution includes one or more of the following: hydrochloric acid solution, acetic acid solution, benzoic acid solution, sulfuric acid solution, nitric acid solution, and phosphoric acid solution, at a concentration of 0.02mol / L-1.0mol / L; and / or The methylation treatment includes: uniformly dispersing the covalent organic framework material and iodomethane in a molar ratio of 1:(4-5) in one or more solutions of acetonitrile, N,N-dimethylformamide, and tetrahydrofuran, and stirring at room temperature for 0.5 h-72 h.

9. A covalent organic framework material with different planarity, characterized in that, It is prepared by the method of any one of claims 1-8.

10. The application of the covalent organic framework materials with different planarity as described in claim 9 in catalytic synthesis.

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