Quinoline type covalent organic framework material, cyano-modified quinoline type covalent organic framework material as well as preparation methods and application of quinoline type covalent organic framework material and cyano-modified quinoline type covalent organic framework material
By introducing quinoline structure and cyano modification into covalent organic framework materials, the problems of expensive catalysts and environmental pollution in the H2O2 production process in the prior art are solved, and the efficient, economical and environmentally friendly photocatalytic production of H2O2 and selective oxidation sulfide ether are achieved.
Patent Information
- Application Number
- CN202510342285.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-21
- Publication Date
- 2025-06-24
AI Technical Summary
The prior art relies on expensive palladium-based catalysts and complex reaction processes when producing hydrogen peroxide (H2O2). The traditional oxidation process is costly and has serious environmental pollution, and the photocatalyst water is unstable and the structure is easily damaged.
A quinoline-type covalent organic framework material was developed, and the covalent organic framework material was formed by introducing quinoline structure and alkynyl groups into the phenylpyrene structure, and the light absorption range of the photocatalyst was further broadened through cyano modification.
The hydrophilicity, water stability and conjugation of covalent organic frame materials are improved, the light absorption range is broadened, the photocatalytic performance is enhanced, and the generation activity of H2O2 and the selective oxidation performance of sulfide under visible light are significantly improved.
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Figure CN120192490A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of covalent organic framework functional materials, and particularly relates to a quinoline-based covalent organic framework material, a cyano-modified quinoline-based covalent organic framework material, and their preparation methods and applications. Background Art
[0002] In recent years, with the development of industrialization, energy consumption has been increasing day by day, and the problems of resource depletion and environmental pollution have become increasingly serious. Therefore, it is imperative to develop a series of secondary and clean energy sources. Hydrogen peroxide (H2O2) has good activity, strong oxidizing property, and high energy density, and its decomposition products are only water and oxygen, which will not cause secondary pollution to the environment. It is hailed as the "cleanest" chemical product. It is reported that many pollutants, including organic dyes, organochlorine pesticides, cyanides, phenols, and antibiotics, can be treated with H2O2 without causing secondary pollution to the environment. Therefore, H2O2 can be used as an environmentally friendly disinfectant to inactivate pathogenic microorganisms.
[0003] Currently, industrial production of H2O2 still relies on the traditional anthraquinone process. This method involves expensive palladium-based catalysts and complex reactions, such as the hydrogenation and oxidation processes of the catalyst, and may also produce toxic by-products. The process is complex, energy-consuming, environmentally polluting, costly, requires a large amount of energy, and is not sustainable. Therefore, it is very important to develop an efficient, economical, and environmentally friendly method for producing H2O2. Using covalent organic framework materials (COFs) for photocatalytic production of H2O2 is considered a green, efficient, and economical way to produce H2O2.
[0004] In addition to the production of H2O2, COFs are also used as photocatalysts for organic transformation reactions. The traditional oxidation processes carried out industrially use harsh conditions and harmful oxidants, producing waste by-products, increasing the operating costs, and having a huge impact on the environment. Therefore, in order to achieve sustainable production of chemicals, it is also necessary to use stable and recyclable photoactive COFs to synthesize value-added organic products. However, most of the photocatalysts currently used are unstable in water and their structures are easily damaged; or the materials are hydrophobic and cannot combine well with water, resulting in poor performance. Therefore, the development of new materials still needs to continue. Summary of the Invention
[0005] For the above reasons, the first object of the present invention is to provide a quinoline-based covalent organic framework material. Based on the phenylpyrene structure, a quinoline structure connected thereto is introduced, and a covalent organic framework material is constructed with a phenyleneethynyl group as a linking group. The introduced quinoline group enhances the conjugation of the covalent organic framework material, broadens the light absorption range; and the water stability and hydrophilicity of the organic framework material are improved; in particular, the ethynyl group also provides reaction sites for subsequent post-modification.
[0006] The second object of the present invention is to provide a preparation method of a quinoline-based covalent organic framework material; while a ligand containing an aniline group and an aldehyde ligand undergo a hydrothermal reaction to form a -C=N- double bond to construct COFs, the added electron-rich olefin participates in the reaction, and the three condense to form a quinoline group; a quinoline group is introduced into the COFs.
[0007] The third object of the present invention is to provide a cyano-modified quinoline-based covalent organic framework material. Abundant cyano groups are introduced into the COFs, further broadening the light absorption range of the photocatalyst, enabling it to perform catalysis under visible light; and this is conducive to the generation of reactive oxygen species, significantly improving the catalytic activity.
[0008] The fourth object of the present invention is to provide a preparation method of a cyano-modified quinoline-based covalent organic framework material. By reacting the alkynyl group in the COFs with tetracyanoethylene, a large number of cyano groups are introduced into the COFs structure to improve the performance of the COFs.
[0009] The fifth object of the present invention is to provide an application of the above-mentioned covalent organic framework material in photocatalytic production of hydrogen peroxide and selective oxidation of thioethers.
[0010] The first object of the present invention can be achieved by adopting the following technical solutions:
[0011] A quinoline-based covalent organic framework material, whose chemical structure is shown in Formula I:
[0012]
[0013] The second object of the present invention can be achieved by adopting the following technical solutions:
[0014] A preparation method of a quinoline-based covalent organic framework material, 1,3,6,8-tetra-(p-aminophenyl)pyrene, 4,4'-(ethyne-1,2-diyl)dibenzaldehyde and styrene are reacted in an organic solvent in the presence of boron trifluoride diethyl ether, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and acetic acid, and the quinoline-based covalent organic framework material is obtained after the reaction ends.
[0015] Furthermore, the molar ratio of 1,3,6,8-tetra-(p-aminophenyl)pyrene, 4,4'-(ethyne-1,2-diyl)dibenzaldehyde and styrene is 1:(1.5 - 2.5):(3.5 - 4.5). Furthermore, the molar ratio of 1,3,6,8-tetra-(p-aminophenyl)pyrene, boron trifluoride diethyl ether and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is (1.2 - 2):1:(0.8 - 1.2).
[0016] Further, the organic solvent is a mixed solvent of 1,2-dichlorobenzene and n-butanol; the volume ratio of 1,2-dichlorobenzene to n-butanol is (1-4):1.
[0017] Further, the concentration of acetic acid is 4-8 mol / L; the addition amount is 5-20% of the volume of the organic solvent.
[0018] Further, the molar volume ratio of 1,3,6,8-tetra-(p-aminophenyl)-pyrene to the organic solvent is (20-40) μmol:1 mL.
[0019] Further, the reaction conditions are: reacting at 110-140 °C for 24-96 h.
[0020] Further, after the reaction is completed, post-treatment is also carried out. The post-treatment process includes purifying the reaction product with an organic reagent and performing vacuum drying after purification.
[0021] Further, the organic reagent is one or more of N,N-dimethylformamide, ethyl acetate, and tetrahydrofuran.
[0022] Further, the purification includes washing and Soxhlet extraction.
[0023] The third object of the present invention can be achieved by adopting the following technical solutions:
[0024] A cyano-modified quinoline-based covalent organic framework material, whose chemical structure is shown in Formula II:
[0025]
[0026] The fourth object of the present invention can be achieved by adopting the following technical solutions:
[0027] A preparation method of a cyano-modified quinoline-based covalent organic framework material, wherein the above-mentioned quinoline-based covalent organic framework material and tetracyanoethylene are heated and reacted under a vacuum state, and the cyano-modified quinoline-based covalent organic framework material is obtained after the reaction is completed.
[0028] Further, the mass ratio of the above-mentioned quinoline-based covalent organic framework material to tetracyanoethylene is 1:(1.8-2.5).
[0029] Further, the above-mentioned quinoline-based covalent organic framework material and tetracyanoethylene are kept spatially separated and do not directly contact.
[0030] Further, the conditions for the heating reaction are at 130-160 °C; the reaction time is 2-24 h.
[0031] The fifth object of the present invention can be achieved by adopting the following technical solutions:
[0032] Use of the quinoline-based covalent organic framework material described above or the cyano-modified quinoline-based covalent organic framework material described above as a photocatalyst for producing hydrogen peroxide or a catalyst for selective oxidation of thioether.
[0033] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0034] 1. For a quinoline-based covalent organic framework material of the present invention, compared with the covalent organic framework material connected by -C=N- bonds, in this application, the -C=N- bond is cyclized into a quinoline structure and directly connected to the large-ring pyrene, which not only enhances the hydrophilicity and water stability of the covalent organic framework material, further enhances the conjugation of the covalent organic framework material, broadens the light absorption range, and improves the photocatalytic performance. And the alkynyl group therein also provides a reaction site for subsequent post-modification, providing a way for further improvement of the performance of the covalent organic framework material.
[0035] 2. For a preparation method of a quinoline-based covalent organic framework material of the present invention, the reaction of aniline groups and aldehyde groups is combined with an electron-rich olefin, and a quinoline-based covalent organic framework material is prepared in one step based on the hydrothermal reaction of the covalent organic framework material. The synthesis is simple and convenient, and can be mass-produced without a cumbersome operation process.
[0036] 3. For the cyano-modified quinoline-based covalent organic framework material of the present invention, a rich amount of cyano groups are introduced into the COFs, further broadening the light absorption range of the photocatalyst, enabling it to catalyze under visible light; the introduction of a rich amount of cyano groups is beneficial to the generation of reactive oxygen species; the synergistic construction significantly improves the generation activity of H2O2 under visible light and the selective oxidation performance of thioether under white light.
[0037] 4. For a preparation method of a cyano-modified quinoline-based covalent organic framework material of the present invention, a large amount of cyano groups are introduced into the COFs structure by reacting the alkynyl group in the COFs with tetracyanoethylene. The synthesis is simple and convenient, and can be mass-produced without a cumbersome operation process. BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Figure 1 X-ray powder diffraction patterns of PPy-COF prepared in Example 1, T4-PPy-COF prepared in Example 4, T8-PPy-COF prepared in Example 5, and T 12 -PPy-COF prepared in Example 6;
[0039] Figure 2 Fourier transform-infrared spectra of PPy-COF prepared in Example 1, T4-PPy-COF prepared in Example 4, T8-PPy-COF prepared in Example 5, and T 12 -PPy-COF prepared in Example 6;
[0040] Figure 3 Scanning electron microscope image of PPy-COF prepared in Example 1;
[0041] Figure 4 X-ray powder diffraction patterns of PPy-COF prepared in Example 1 after being soaked in different solvents and aqueous solutions with different pH values for 24 h;
[0042] Figure 5 Thermogravimetric curves of PPy-COF prepared in Example 1, T4-PPy-COF prepared in Example 4, T8-PPy-COF prepared in Example 5, and T 12 -PPy-COF prepared in Example 6;
[0043] Figure 6 Photocatalytic hydrogen peroxide production rate diagrams of PPy-COF prepared in Example 1, T4-PPy-COF prepared in Example 4, T8-PPy-COF prepared in Example 5, and T 12 -PPy-COF prepared in Example 6;
[0044] Figure 7 1H NMR spectrum of the product of photocatalytic oxidation of methyl phenyl sulfide by T8-PPy-COF prepared in Example 5. Detailed implementation manners
[0045] The technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only partial embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.
[0046] In the existing anthraquinone process for producing H2O2, it involves expensive palladium-based catalysts and complex reactions, such as the hydrogenation and oxidation processes of the catalyst, and may also produce toxic by-products. If a photocatalytic reaction is used, most of the photocatalysts used in the prior art are unstable in water and their structures are easily damaged; or the materials are hydrophobic and cannot combine well with water, resulting in poor performance; and the traditional oxidation process has a high production cost, requires harsh oxidants and produces toxic by-products or heavy metal waste.
[0047] Therefore, the present application provides a quinoline-based covalent organic framework material, a cyano-modified quinoline-based covalent organic framework material, and their preparation methods and applications, which have excellent performance as photocatalytic hydrogen peroxide production or sulfur ether selective oxidation catalysts.
[0048] A quinoline-based covalent organic framework material, whose chemical structure is shown in Formula I:
[0049]
[0050] A quinoline-based covalent organic framework material with the structure shown in Formula I, in which the polycyclic pyrene is used as the basic unit, is directly connected to the quinoline structure, and a phenyl group is also connected to the quinoline ring. The D-A structure is distinct, providing effective charge separation. Compared with the covalent organic framework material connected by -C=N- bonds, in this application, the -C=N- bonds are cyclized and directly connected to the pyrene of the macrocycle, which not only enhances the hydrophilicity and water stability of the covalent organic framework material, but also further enhances the conjugation of the covalent organic framework material, broadens the light absorption range, and improves the photocatalytic performance. And the alkynyl group therein also provides reaction sites for subsequent post-modification, providing a way for further improvement of the performance of the covalent organic framework material.
[0051] A preparation method of a quinoline-based covalent organic framework material, 1,3,6,8-tetra-(p-aminophenyl)-pyrene, 4,4'-(ethyne-1,2-diyl) dibenzaldehyde and styrene react in an organic solvent in the presence of boron trifluoride diethyl ether, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and acetic acid, and the quinoline-based covalent organic framework material is obtained after the reaction ends; the reaction process is as follows:
[0052]
[0053] The pyrene structure ligand with aniline groups, the benzaldehyde ligand containing alkynyl and the electron-rich olefin styrene are combined and reacted. The aldehyde group, aniline and vinyl can form a ring to form tetrahydroquinoline, and then form quinoline through an oxidation process, directly connecting the polycyclic pyrene with the quinoline structure and forming a covalent organic framework material. The reaction is based on the hydrothermal reaction of the covalent organic framework material, and the synthesis is simple and convenient, and can be mass-produced without cumbersome operation processes.
[0054] As one of the embodiments, the molar ratio of 1,3,6,8-tetra-(p-aminophenyl)-pyrene, 4,4'-(ethyne-1,2-diyl) dibenzaldehyde and styrene is 1:(1.5 - 2.5):(3.5 - 4.5).
[0055] As one of the embodiments, the molar ratio of 1,3,6,8-tetra-(p-aminophenyl)-pyrene, boron trifluoride diethyl ether and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is (1.2 - 2):1:(0.8 - 1.2). 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone is used as the oxidant of the reaction and can oxidize the generated tetrahydroquinoline into quinoline.
[0056] As one of the embodiments, the organic solvent is a mixed solvent of 1,2-dichlorobenzene and n-butanol; the volume ratio of 1,2-dichlorobenzene to n-butanol is (1-4):1.
[0057] As one of the embodiments, the concentration of acetic acid is 4-8 mol / L; the addition amount is 5-20% of the volume of the organic solvent.
[0058] As one of the embodiments, the molar volume ratio of 1,3,6,8-tetra-(p-aminophenyl)-pyrene to the organic solvent is (20-40) μmol:1 mL.
[0059] As one of the embodiments, the reaction conditions are: reacting at 110-140 °C for 24-96 h.
[0060] As one of the embodiments, post-treatment is also carried out after the reaction. The process of post-treatment includes purifying the reaction product with an organic reagent, and performing vacuum drying after purification.
[0061] As one of the embodiments, the organic reagent is one or more of N,N-dimethylformamide, ethyl acetate, and tetrahydrofuran.
[0062] As one of the embodiments, the purification includes washing and Soxhlet extraction.
[0063] As one of the embodiments, after washing with N,N-dimethylformamide and ethyl acetate, Soxhlet extraction of the quinoline-based covalent organic framework material is carried out with tetrahydrofuran.
[0064] A cyano-modified quinoline-based covalent organic framework material, whose chemical structure is shown in Formula II:
[0065]
[0066] The introduction of abundant cyano groups in COFs further broadens the light absorption range of the photocatalyst, enabling it to catalyze under visible light; the introduction of abundant cyano groups is beneficial to the generation of reactive oxygen species; the synergistic construction significantly improves the generation activity of H2O2 under visible light and the selective oxidation performance of thioethers under white light.
[0067] A preparation method of a cyano-modified quinoline-based covalent organic framework material. The above-mentioned quinoline-based covalent organic framework material and tetracyanoethylene are heated and reacted under a vacuum state, and the cyano-modified quinoline-based covalent organic framework material is obtained after the reaction ends; the reaction process is as follows:
[0068]
[0069] The post-synthesis method is used to prepare the cyano-modified quinoline-based covalent organic framework material. By utilizing the reaction between alkynyl and vinyl groups and reacting with tetracyanoethylene, a large number of cyano groups are modified into the covalent organic framework, which is beneficial for the generation of reactive oxygen species and contributes to the generation activity of H2O2 and the selective oxidation performance of thioether under white light.
[0070] As one of the embodiments, the mass ratio of the above-mentioned quinoline-based covalent organic framework material to tetracyanoethylene is 1:(1.8 - 2.5).
[0071] As one of the embodiments, the above-mentioned quinoline-based covalent organic framework material and tetracyanoethylene are kept spatially separated and do not directly contact each other.
[0072] As one of the embodiments, the conditions for the heating reaction are at 130 - 160 °C; the reaction time is 2 - 24 h.
[0073] The following will be further illustrated with specific examples.
[0074] Example 1 Preparation of PPy-COF
[0075] Weigh 50 μmol of 4,4'-(ethyne-1,2-diyl)dibenzaldehyde, 32 μmol of 1,3,6,8-tetra-(p-aminophenyl)pyrene, and 22 μmol of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and add them into a glass tube; successively add 22 μmol of BF3·OEt2, 0.25 mL of n-BuOH, 0.1 mL of 6M acetic acid aqueous solution, 130 μmol of styrene, and 0.75 mL of 1,2-dichlorobenzene; seal the glass tube through a hydrogen-oxygen flame; place the glass tube in an ultrasonic bath and ultrasonically treat it for 10 min; place the glass tube in an oven and heat it at 120 °C for 72 h; after cooling to room temperature, open the glass tube, collect the solid product by suction filtration, and wash the solid product with N,N-dimethylformamide and ethyl acetate multiple times; perform Soxhlet extraction with tetrahydrofuran, take it out and dry it to obtain the above-mentioned quinoline-based covalent organic framework material, named PPy-COF.
[0076] Example 2 Preparation of PPy-COF
[0077] Weigh 65 μmol of 4,4'-(ethyne-1,2-diyl)dibenzaldehyde, 32 μmol of 1,3,6,8-tetra(4-aminophenyl)pyrene, and 27 μmol of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and add them into a glass tube; successively add 32.4 μmol of BF3·OEt2, 0.8 mL of n-BuOH, 0.08 mL of 6 M aqueous acetic acid solution, 112 μmol of styrene, and 0.8 mL of 1,2-dichlorobenzene; seal the glass tube with a hydrogen-oxygen flame; place the glass tube in an ultrasonic bath and ultrasonically treat it for 10 min; place the glass tube in an oven and heat it at 140 °C for 24 h; after cooling to room temperature, open the glass tube, collect the solid product by suction filtration, and wash the solid product with N,N-dimethylformamide and ethyl acetate multiple times; perform Soxhlet extraction with tetrahydrofuran, take it out and dry it to obtain the quinoline-based covalent organic framework material, named PPy-COF.
[0078] Example 3 Preparation of PPy-COF
[0079] Weigh 80 μmol of 4,4'-(ethyne-1,2-diyl)dibenzaldehyde, 32 μmol of 1,3,6,8-tetra(4-aminophenyl)pyrene, and 16 μmol of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and add them into a glass tube; successively add 12.8 μmol of BF3·OEt2, 0.16 mL of n-BuOH, 0.16 mL of 6 M aqueous acetic acid solution, 144 μmol of styrene, and 0.64 mL of 1,2-dichlorobenzene; seal the glass tube with a hydrogen-oxygen flame; place the glass tube in an ultrasonic bath and ultrasonically treat it for 10 min; place the glass tube in an oven and heat it at 110 °C for 96 h; after cooling to room temperature, open the glass tube, collect the solid product by suction filtration, and wash the solid product with N,N-dimethylformamide and ethyl acetate multiple times; perform Soxhlet extraction with tetrahydrofuran, take it out and dry it to obtain the quinoline-based covalent organic framework material, named PPy-COF.
[0080] Example 4 Preparation of T4-PPy-COF
[0081] Place 15 mg of PPy-COF and 30 mg of tetracyanoethylene in a pressure-resistant tube. Place the tetracyanoethylene in a glass tube with one end sealed to keep them spatially separated to prevent direct contact between the two; after evacuating the air from the pressure-resistant tube, place the tube in an oven at 140 °C and react for 4 h; cool to room temperature, wash the obtained powder with N,N-dimethylformamide and ethyl acetate, and dry it to obtain the cyano-modified quinoline-based covalent organic framework material, named T4-PPy-COF.
[0082] Example 5 Preparation of T8-PPy-COF
[0083] Place 15 mg of PPy-COF and 30 mg of tetracyanoethylene in a pressure-resistant tube. Place the tetracyanoethylene in a glass tube sealed at one end, maintaining spatial separation to prevent direct contact between the two. After evacuating the air from the pressure-resistant tube, place the tube in an oven at 140 °C and react for 8 h. Cool to room temperature, wash the resulting powder with N,N-dimethylformamide and ethyl acetate, and dry to obtain the cyano-modified quinoline-based covalent organic framework material, named T8-PPy-COF.
[0084] Example 6T 12 Preparation of -PPy-COF
[0085] Place 15 mg of PPy-COF and 30 mg of tetracyanoethylene in a pressure-resistant tube. Place the tetracyanoethylene in a glass tube sealed at one end, maintaining spatial separation to prevent direct contact between the two. After evacuating the air from the pressure-resistant tube, place the tube in an oven at 140 °C and react for 12 h. Cool to room temperature, wash the resulting powder with N,N-dimethylformamide and ethyl acetate, and dry to obtain the cyano-modified quinoline-based covalent organic framework material, named T 12 -PPy-COF.
[0086] Preparation of Example 7 T4-PPy-COF
[0087] Place 15 mg of PPy-COF and 27 mg of tetracyanoethylene in a pressure-resistant tube. Place the tetracyanoethylene in a glass tube sealed at one end, maintaining spatial separation to prevent direct contact between the two. After evacuating the air from the pressure-resistant tube, place the tube in an oven at 130 °C and react for 4 h. Cool to room temperature, wash the resulting powder with N,N-dimethylformamide and ethyl acetate, and dry to obtain the cyano-modified quinoline-based covalent organic framework material, named T4-PPy-COF.
[0088] Preparation of Example 8 T4-PPy-COF
[0089] Place 15 mg of PPy-COF and 37.5 mg of tetracyanoethylene in a pressure-resistant tube. Place the tetracyanoethylene in a glass tube sealed at one end, maintaining spatial separation to prevent direct contact between the two. After evacuating the air from the pressure-resistant tube, place the tube in an oven at 160 °C and react for 4 h. Cool to room temperature, wash the resulting powder with N,N-dimethylformamide and ethyl acetate, and dry to obtain the cyano-modified quinoline-based covalent organic framework material, named T4-PPy-COF.
[0090] Test Example:
[0091] (1) For PPy-COF prepared in Example 1, T4-PPy-COF prepared in Example 4, T8-PPy-COF prepared in Example 5, T prepared in Example 6 12-PPy-COF was subjected to X-ray powder diffraction, and the X-ray powder diffraction pattern is as Figure 1 shown.
[0092] It can be seen from the results of the X-ray powder diffraction test that the diffraction pattern of the synthesized PPy-COF is basically consistent with the simulated diffraction pattern in terms of peak positions, indicating that the synthesized PPy-COF is in a pure phase, and the cyanide-modified quinoline-based covalent organic framework materials T4-PPy-COF, T8-PPy-COF, T 12 -PPy-COF have the same main framework. From the diffraction pattern, the diffraction peaks of all covalent organic framework materials are very strong and sharp, indicating that the synthesized COFs have good crystallinity.
[0093] (2) Fourier transform-infrared spectroscopy detection was carried out on the PPy-COF prepared in Example 1, as well as the 1,3,6,8-tetra-(p-aminophenyl)-pyrene ligand and the 4,4'-(ethyne-1,2-diyl) dibenzaldehyde ligand; Fourier transform-infrared spectroscopy detection was carried out on the PPy-COF prepared in Example 1, the T4-PPy-COF prepared in Example 4, the T8-PPy-COF prepared in Example 5, and the T 12 -PPy-COF prepared in Example 6, and the results are as Figure 2 shown.
[0094] From Figure 2 the infrared spectrum, it can be clearly observed that the aldehyde group characteristic peaks at 2837 cm -1 and 1699 cm -1 in the 4,4'-(ethyne-1,2-diyl) dibenzaldehyde ligand disappear, and the characteristic peak of the carbonyl group in the ligand shifts from 1699 cm -1 to 1635 cm -1 , and the amino characteristic peak in the 1,3,6,8-tetra-(p-aminophenyl)-pyrene monomer disappears, indicating that coordination has occurred between the monomers. As the modification reaction time increases, the intensity of the -C≡N- characteristic peak gradually becomes stronger.
[0095] (3) Scanning electron microscope SEM observation was carried out on the PPy-COF prepared in Example 1, and the appearance diagram is as Figure 3 shown.
[0096] From Figure 3 it can be seen that the prepared PPy-COF is in a uniform columnar shape and has good crystallinity.
[0097] (4) 5 mg of the PPy-COF prepared in Example 1 was soaked in 5 mL of different solvents and aqueous solutions with different pH values for 24 h for stability testing, and the test results are as Figure 4 shown.
[0098] Figure 4 Among them, after 24 hours of immersion, the framework of the XRD diffraction peaks of PPy-COF basically did not change, indicating that PPy-COF has good chemical stability and water stability. Most of the reported covalent organic frameworks have poor stability, especially water instability, while the quinoline-based covalent organic framework material of this application has good stability.
[0099] (5) Thermogravimetric analysis was carried out on PPy-COF prepared in Example 1, T4-PPy-COF prepared in Example 4, T8-PPy-COF prepared in Example 5, and T 12 -PPy-COF prepared in Example 6, and the thermogravimetric curves are as Figure 5 shown.
[0100] Figure 5 Among them, PPy-COF, T4-PPy-COF, T8-PPy-COF, and T 12 -PPy-COF showed insignificant weight loss within 500 °C, indicating good thermal stability.
[0101] Test examples:
[0102] (1) Study on the performance of photocatalytic hydrogen peroxide production and selective oxidation performance
[0103] Weigh 5 mg of PPy-COF, T4-PPy-COF, T8-PPy-COF, and T 12 -PPy-COF respectively and add them to the photocatalytic reaction flask. Then add 10 mL of aqueous solution and 5 mL of benzyl alcohol solution, and bubble with oxygen for 30 minutes. After that, irradiate with LED light for 1 hour. The hydrogen peroxide content in the photocatalytic reaction flask was measured by the iodometric method, and the results are as Figure 6 shown.
[0104] The results of the iodometric method showed that through 1 hour of light irradiation, the hydrogen peroxide production rate of PPy-COF reached 658.9 μmol / g / h; that of T4-PPy-COF was 1018.3 μmol / g / h; that of T8-PPy-COF was 1264.7 μmol / g / h; and that of T 12 -PPy-COF was 1044.8 μmol / g / h. Without the need to add additional photosensitizers, it is of great significance for the development of new energy and environmental protection.
[0105] (2) Study on the selective oxidation performance of thioethers:
[0106] Using T8-PPy-COF as the catalyst for thioether oxidation, weigh 5 mg of T8-PPy-COF and add it to the reaction flask. Then add 5 mL of methanol solution and 0.2 mmol of methyl phenyl sulfide, and disperse them by ultrasonic treatment. Bubble oxygen for 30 min and irradiate under a white light for 14 h. After the reactants are dried by rotation, add 10.7 mg of mesitylene, add deuterated chloroform, and calculate the yield of the substrate by nuclear magnetic resonance quantitative method (the molar number of the product is obtained by the ratio of the number of protons and the integral area of the product and the internal standard, and then the yield is obtained by the ratio of the molar number to the theoretical molar number); the nuclear magnetic resonance results are as Figure 7 shown.
[0107] The calculated yield of sulfoxide is 99%.
[0108] In summary, the present invention discloses a quinoline-based covalent organic framework material and a cyano-modified quinoline-based covalent organic framework material. Compared with the covalent organic framework material connected by -C=N- bonds, in this application, the -C=N- bond is cyclized into a quinoline structure and directly connected to the pyrene of the macrocycle, which not only enhances the hydrophilicity and water stability of the covalent organic framework material, but also further enhances the conjugation of the covalent organic framework material, broadens the light absorption range, and improves the photocatalytic performance. Through the post-modification of alkynyl groups, rich cyano groups are introduced into the COFs, further broadening the light absorption range of the photocatalyst, enabling it to catalyze under visible light; the introduction of rich cyano groups is beneficial to the generation of reactive oxygen species; the synergistic construction significantly improves the generation activity of H2O2 under visible light and the selective oxidation performance of thioether under white light.
[0109] The above embodiments are only the preferred embodiments of the present invention and cannot be used to limit the scope of protection of the present invention. Any non-substantive changes and substitutions made by those skilled in the art on the basis of the present invention belong to the scope of protection required by the present invention.
Claims
1. A quinoline-type covalent organic framework material, characterized in that: Its chemical structure is shown in Formula I:
2. A method for preparing a quinoline-type covalent organic framework material, characterized in that: 1,3,6,8-tetrakis-(p-aminophenyl)-pyrene, 4,4'-(acetylene-1,2-diyl)benzaldehyde and styrene are reacted in an organic solvent in the presence of boron trifluoride etherate, 2,3-dichloro-5,6-dicyano-1,4-benzoquinone and acetic acid, and the quinoline type covalent organic framework material is obtained after the reaction is completed.
3. The method for preparing a quinoline-type covalent organic framework material according to claim 2, characterized in that: The molar ratio of 1,3,6,8-tetrakis-(p-aminophenyl)-pyrene, 4,4'-(ethynyl-1,2-diyl)benzaldehyde and styrene is 1:(1.5-2.5):(3.5-4.5); The molar ratio of 1,3,6,8-tetrakis-(p-aminophenyl)-pyrene, boron trifluoride ethyl ether and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone is (1.2-2):1:(0.8-1.2).
4. The method for preparing a quinoline-type covalent organic framework material according to claim 2, characterized in that: The organic solvent is a mixed solvent of 1,2-dichlorobenzene and n-butanol; the volume ratio of 1,2-dichlorobenzene to n-butanol is (1-4):1; The concentration of the acetic acid is 4-8 mol / L; the amount added is 5-20% of the volume of the organic solvent; The molar volume ratio of 1,3,6,8-tetrakis-(p-aminophenyl)-pyrene to the organic solvent is (20-40) μmol:1 mL; The reaction conditions are: 110-140°C for 24-96h.
5. The method for preparing the quinoline type covalent organic framework material according to claim 2, characterized in that: After the reaction is completed, post-treatment is performed, and the post-treatment process includes purifying the reaction product with an organic reagent and vacuum drying after purification; Preferably, the organic reagent is one or more of N,N-dimethylformamide, ethyl acetate and tetrahydrofuran; preferably, the purification comprises washing and Soxhlet extraction.
6. A cyano-modified quinoline-type covalent organic framework material, characterized in that: Its chemical structure is shown in Formula II:
7. A method for preparing a cyano-modified quinoline-type covalent organic framework material, characterized in that ， The quinoline covalent organic framework material according to claim 1 is subjected to a heating reaction with tetracyanoethylene under a vacuum state, and the cyano-modified quinoline covalent organic framework material is obtained after the reaction is completed.
8. The method for preparing the cyano-modified quinoline-type covalent organic framework material according to claim 7, characterized in that ， The mass ratio of the quinoline type covalent organic framework material and tetracyanoethylene according to claim 1 is 1:(1.8-2.5); The quinoline-type covalent organic framework material described in claim 1 is spatially separated from tetracyanoethylene and is not in direct contact with it.
9. The method for preparing a cyano-modified quinoline-type covalent organic framework material according to claim 7, characterized in that: The heating reaction conditions are 130-160°C; the reaction time is 2-24h.
10. Use of the quinoline type covalent organic framework material according to claim 1 or the cyano-modified quinoline type covalent organic framework material according to claim 3 as a photocatalytic catalyst for producing hydrogen peroxide or selective oxidation of thioethers.