A porous crystalline quinoline-based organic framework photocatalytic material and a preparation method and application thereof
By introducing quinoline groups into covalent organic framework materials and combining imine formation with post-synthetic modification reactions, the structural instability of the materials under acidic conditions was solved, achieving highly efficient photocatalytic hydrogen evolution performance and demonstrating broad application prospects.
Patent Information
- Application Number
- CN202411045817.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-01
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2044-08-01
AI Technical Summary
Existing covalent organic framework materials are prone to hydrolysis under acidic conditions, resulting in structural instability that affects their photocatalytic hydrogen evolution performance. Furthermore, poor electron delocalization leads to low charge separation and transfer efficiency.
By introducing quinoline groups and combining reversible imine formation reactions with irreversible post-synthetic modification reactions, porous crystalline quinoline-based organic framework materials are prepared, thereby improving their chemical stability and photocatalytic performance.
The prepared quinolinyl covalent organic framework material is structurally stable in strong acid or strong alkali solutions, exhibits ultra-high photocatalytic hydrogen evolution efficiency, and possesses good chemical stability and efficient photocatalytic performance.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of covalent organic framework materials, in particular to a porous crystalline quinoline-based organic framework photocatalytic material and a preparation method and application thereof. BACKGROUND
[0002] With the increasing concern of global energy crisis and environmental pollution, the demand for clean and renewable energy is rapidly increasing. Hydrogen energy is considered as one of the most promising alternatives to fossil fuels due to its environmental friendliness, cost-effectiveness and renewability. Therefore, photocatalytic hydrogen evolution has become a popular research direction. Metal-free covalent organic frameworks (COFs) have high crystallinity, strong π-bridging and structural designability, which show great potential in photocatalytic hydrogen evolution in semiconductor polymer photocatalysts. COFs have diverse framework structures, large specific surface area and porosity, and their morphology and hydrophilicity can be precisely controlled, which is crucial for optimizing their photocatalytic performance. In addition, the modular nature of COFs allows the integration of various functional groups and the design of hierarchical structures, further expanding their potential in photocatalysis.
[0003] Although significant progress has been made in the synthesis of COFs, optimizing their chemical stability and application performance remains a major challenge. For example, imine-linked COFs are prone to hydrolysis under acidic conditions and are susceptible to amine exchange, which can weaken their structure and affect their durability. In addition, the suboptimal electronic delocalization of imine bonds hinders the charge separation and transfer required for efficient photocatalysis. Therefore, addressing these challenges can better exploit the potential of COFs in photocatalytic hydrogen evolution.
[0004] To construct highly stable and fully conjugated COFs, people have explored new chemical methods through innovative synthesis strategies. One approach involves combining reversible imine formation reactions with irreversible post-synthesis modification reactions, which can significantly improve the stability of the resulting COFs. The introduction of oxygen-containing heterocycles such as oxazole, thiazole and quinoline into the framework through post-synthesis modification has been shown to improve the structural stability of imine-based COFs. However, despite these modifications in structural stability, the application performance of COFs in photocatalytic hydrogen evolution remains to be explored. Therefore, designing and synthesizing new quinoline-functionalized covalent organic framework materials show promising application prospects in the field of photocatalytic hydrogen evolution. SUMMARY
[0005] In view of this, the present application proposes a porous crystalline quinoline-based organic framework photocatalytic material and a preparation method and application thereof, which aims to construct new quinoline-functionalized covalent organic framework materials and further improve the performance of COFs in photocatalytic hydrogen evolution.
[0006] The technical scheme of the present application is implemented as follows:
[0007] The present application provides a kind of porous crystalline quinoline-based organic framework photocatalytic material, its structural formula is:
[0008]
[0009] The present application also provides the preparation method of the porous crystalline quinoline-based organic framework photocatalytic material, comprising the following steps:
[0010] (1) the reaction monomer 1,3,6,8-tetrakis (4-formaldehyde phenyl) pyrene and p-phenylenediamine are weighed, added into mixed solvent, mixed, then catalyst is added, and reacted at 100-150 DEG C under nitrogen atmosphere for 24-72 h; after reaction, filtration, washing and drying are carried out to obtain imine bond framework compound;
[0011] (2) the imine bond framework compound and aromatic alkyne are uniformly dispersed in solvent, and catalyst is added, and reacted at 100-150 DEG C under N2 atmosphere for 24-72 h; after reaction, filtration, washing and drying are carried out to obtain porous crystalline quinoline-based organic framework photocatalytic material, which is recorded as Qu-CN-COF.
[0012] Preferably, the stoichiometric ratio of the reaction monomer 1,3,6,8-tetrakis (4-formaldehyde phenyl) pyrene and p-phenylenediamine is 1:2; the mixed solvent is o-dichlorobenzene and n-butanol, and the volume ratio of o-dichlorobenzene and n-butanol is 1:1-4:1; the mass-volume ratio of the reaction monomer and mixed solvent is 1 mg:30 μL.
[0013] Preferably, the catalyst in (1) is 6M glacial acetic acid solution; and the catalyst in (2) is boron trifluoride ether and tetrachloro-p-quinone.
[0014] Preferably, the molar ratio of the imine bond framework material and aromatic alkyne is 1:1-3; and the molar ratio of boron trifluoride ether, tetrachloro-p-quinone and aromatic alkyne is 1:1:1-1:1:3.
[0015] Preferably, the aromatic alkyne in (2) is 4-ethynylbenzonitrile, and the solvent is any one of toluene, acetone and carbon tetrachloride.
[0016] Preferably, the solvent used for washing is at least one of tetrahydrofuran and ethanol.
[0017] A porous crystalline quinoline-based organic framework photocatalytic material is prepared by any one of the preparation methods of the present application.
[0018] The present application also provides the application of the porous crystalline quinoline-based organic framework photocatalytic material in photocatalytic hydrogen production.
[0019] Preferably, the porous crystalline quinoline-based covalent organic framework is used as a photocatalyst for hydrogen production after loading metal elements, and the metal elements include one or more of Cu, Pt, Ir, Pd, Ni, Co and Ru.
[0020] Compared with the prior art, the present application has the following beneficial effects:
[0021] The present application provides a porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic material and a preparation method thereof. The material has a novel structure, a simple and inexpensive preparation process, and the quinoline-based covalent organic framework material of the present application has a stable crystal structure and a uniform pore size distribution. Compared with the imine bond framework, the quinoline-based covalent organic framework material of the present application also has good chemical stability, and the crystal structure is still relatively stable in strong acid or strong base solution. Under light conditions, the porous crystalline quinoline-based organic framework (Qu-CN-COF) material loaded with Pt shows ultra-high photocatalytic hydrogen evolution efficiency, and has a broad application prospect in the field of photocatalytic hydrogen production. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 Synthesis diagram of the porous crystalline quinoline-based organic framework photocatalytic material
[0023] Figure 2 N2 adsorption-desorption curve of the porous crystalline imine bond covalent organic framework (TF-PD-COF) photocatalytic material obtained in Example 1 at 77K.
[0024] Figure 3 Pore size distribution curve of the porous crystalline imine bond covalent organic framework (TF-PD-COF) photocatalytic material of Example 1 calculated by NLDFT method.
[0025] Figure 4 Infrared spectrum spectrum of the porous crystalline covalent imine bond organic framework (TF-PD-COF) photocatalytic material obtained in Example 1.
[0026] Figure 5 N2 adsorption-desorption curve of the porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic material obtained in Example 1 at 77K.
[0027] Figure 6 Pore size distribution curve of the porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic material of Example 1 calculated by NLDFT method.
[0028] Figure 7 Infrared spectrum spectrum of the porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic material obtained in Example 1.
[0029] Figure 8 Figure 1 shows the hydrogen production cycle performance of the porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic material obtained in Example 1.
[0030] Figure 9 Figure 2 shows the X-ray diffraction spectra of the porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic material obtained in Example 1 before and after acid-base treatment. DETAILED DESCRIPTION
[0031] In order to better understand the technical content of the present application, the following specific examples are provided to further illustrate the present application.
[0032] The experimental methods used in the embodiments of the present application are conventional methods unless otherwise specified.
[0033] The materials, reagents, etc. used in the embodiments of the present application can be obtained from commercial channels unless otherwise specified.
[0034] The synthesis route of the porous crystalline quinoline-based organic framework photocatalytic material of the embodiments of the present application is shown in Figure 1 .
[0035] Example 1
[0036] Synthesis of TF-PD-COF material
[0037] A glass ampoule was sequentially charged with 1,3,6,8-tetra(4-formylphenyl)pyrene (24.7 mg, 0.04 mmol), p-phenylenediamine (8.7 mg, 0.08 mmol) and a mixture of o-dichlorobenzene and n-butanol (0.5 / 0.5 mL, v / v). The mixture was ultrasonically mixed for 10 min, and ice acetic acid (6 M, 0.1 mL) was added as a catalyst. After three cycles of liquid nitrogen freezing-vacuumizing-thawing, the glass ampoule was flame-sealed under vacuum and placed in a 120 °C oven for 72 h. After the reaction was completed, the product was collected and washed with tetrahydrofuran and ethanol three times, respectively, then was soxhlet extracted with tetrahydrofuran for 24 h, and finally was dried by heating at 120 °C under vacuum for 12 h. A yellow powder was obtained, which was the porous crystalline imine-based organic framework (TF-PD-COF) material, with a yield of 75%. The nitrogen adsorption-desorption curve is shown in Figure 2 , the BET specific surface area was 2506 m 2 ·g -1 , and the type IV isotherm curve not only indicated the mesoporous nature of the framework material, but also the pore size distribution curve of TF-PD-COF calculated by the NLDFT method is shown in Figure 3The average pore size is 1.68 nm as shown in the nitrogen adsorption / desorption curve Figure 4 The information analysis result is that the imine bond (C=N) characteristic absorption peak appears at 1624 cm -1 , indicating the synthesis of the porous crystalline imine bond organic framework (TF-PD-COF).
[0038] Synthesis of Qu-CN-COF material
[0039] TF-PD-COF (158 mg, 0.5 mmol), 4-ethynylbenzonitrile (64 mg, 0.5 mmol), boron trifluoride etherate (BF3·OEt2) (27 μL, 0.215 mmol), chloranil (53 mg, 0.215 mmol) and 20 mL of toluene were added into a 25 mL hard glass tube, heated in an oil bath at 110°C under N2atmosphere for 72 h, washed with tetrahydrofuran after cooling, quenched with saturated NaHCO3, extracted with tetrahydrofuran for 12 h and dried at 120°C under vacuum for 24 h to obtain the porous crystalline quinolyl organic framework (Qu-CN-COF) photocatalytic material.
[0040] The obtained porous crystalline quinolyl organic framework (Qu-CN-COF) photocatalytic material was characterized, and the nitrogen adsorption / desorption curve is shown in Figure 5 , and the BET specific surface area is 1207 m 2 ·g -1 The Qu-CN-COF IV isotherm not only indicates the mesoporous nature, but also indicates that the chemical modification does not significantly change the framework structure of the COF. The Qu-CN-COF pore size distribution curve calculated by the NLDFT method is shown in Figure 6 , and the average pore size is 1.33 nm.
[0041] The infrared spectrum is shown in Figure 7 , and the information analysis result is that the prepared COFs stretching vibration peak is evaluated by Fourier transform infrared spectroscopy (FT-IR). A significant peak appears at 1624 cm -1 , which belongs to C=N vibration, indicating the existence of residual imine bond COFs. At the same time, the characteristic peak of 1602 cm -1 corresponding to the stretching frequency of quinoline functional group is observed, and the C≡N characteristic peak of Qu-CN-COF appears at 2228 cm -1 .
[0042] Example 2
[0043] Synthesis of TF-PD-COF material
[0044] A glass ampoule was charged with 1,3,6,8-tetra(4-formylphenyl)pyrene (24.7 mg), p-Phenylenediamine (8.7 mg) and a mixture of o-dichlorobenzene and n-butanol (0.8 / 0.2 mL, v / v) in sequence. The mixture was sonicated for 10 min to mix well. Glacial acetic acid (6 M, 0.1 mL) was added as a catalyst in the mixture. After three liquid nitrogen freeze-pump-thaw cycles, the glass ampoule was flame-sealed under vacuum and left to react at 150 °C for 24 h. After the reaction, the product was collected and washed with tetrahydrofuran and ethanol for three times, respectively, and then was soxhlet extracted with tetrahydrofuran for 24 h. Finally, it was dried at 120 °C under vacuum for 12 h to give a yellow powder, which was the porous crystalline imine-linked organic framework (TF-PD-COF) material.
[0045] Synthesis of Qu-CN-COF material
[0046] A 25 mL hard glass tube was charged with TF-PD-COF (158 mg, 0.5 mmol), 4-ethynylbenzonitrile (64 mg, 0.5 mmol), boron trifluoride etherate (BF3·OEt2) (63 μL, 0.5 mmol), chloranil (123 mg, 0.5 mmol) and 20 mL acetone. It was heated at 150 °C in an oil bath under N2atmosphere for 24 h. After cooling, it was washed with tetrahydrofuran, quenched with saturated NaHCO3, soxhlet extracted with tetrahydrofuran for 12 h and dried at 120 °C under vacuum for 24 h to give the porous crystalline quinolyl-based organic framework (Qu-CN-COF) photocatalytic material.
[0047] Example 3
[0048] Synthesis of TF-PD-COF material
[0049] A glass ampoule was charged with 1,3,6,8-tetra(4-formylphenyl)pyrene (24.7 mg), p-Phenylenediamine (8.7 mg) and a mixture of o-dichlorobenzene and n-butanol (0.5 / 0.5 mL, v / v) in sequence. The mixture was sonicated for 10 min to mix well. Glacial acetic acid (6 M, 0.1 mL) was added as a catalyst in the mixture. After three liquid nitrogen freeze-pump-thaw cycles, the glass ampoule was flame-sealed under vacuum and left to react at 100 °C for 72 h. After the reaction, the product was collected and washed with tetrahydrofuran and ethanol for three times, respectively, and then was soxhlet extracted with tetrahydrofuran for 24 h. Finally, it was dried at 120 °C under vacuum for 12 h to give a yellow powder, which was the porous crystalline imine-linked organic framework (TF-PD-COF) material.
[0050] Synthesis of Qu-CN-COF material
[0051] TF-PD-COF (158 mg, 0.5 mmol), 4-ethynylbenzonitrile (191 mg, 1.5 mmol), boron trifluoride etherate (BF3·OEt2) (63 μL, 0.5 mmol), chloranil (123 mg, 0.5 mmol) and 20 mL of carbon tetrachloride were added into a 25 mL hard glass tube. After heating in an oil bath at 100 °C for 72 h under N2atmosphere, the product was washed with tetrahydrofuran, quenched with saturated NaHCO3, and extracted with tetrahydrofuran for 12 h and dried under vacuum at 120 °C for 24 h to obtain the porous crystalline quinolyl organic framework (Qu-CN-COF) photocatalytic material.
[0052] Comparative Example 1
[0053] This comparative example is the TF-PD-COF material obtained in the first step of Example 1.
[0054] Synthesis of TF-PD-COF material
[0055] A glass ampoule was sequentially charged with 1,3,6,8-tetra(4-formylphenyl)pyrene (24.7 mg), p-phenylenediamine (8.7 mg) and a mixture of o-dichlorobenzene and n-butanol (0.5 / 0.5 mL, v / v). The mixture was ultrasonically mixed for 10 min, and glacial acetic acid (6 M, 0.1 mL) was added as a catalyst. After three cycles of liquid nitrogen freezing-vacuum pumping-thawing, the glass ampoule was flame-sealed under vacuum and left to react at 120 °C for 72 h. After the reaction, the product was collected and washed with tetrahydrofuran and ethanol three times, respectively, and then extracted with tetrahydrofuran for 24 h. Finally, the product was dried under vacuum at 120 °C for 12 h to obtain a yellow powder, which was the product TF-PD-COF.
[0056] Comparative Example 2
[0057] The difference between this example and Example 1 is that 4-ethynylbenzonitrile is replaced by phenylacetylene in the synthesis step of Qu-CN-COF material, and the other operations are the same as those in Example 1.
[0058] Test Example 1: Test of the photocatalytic hydrogen evolution performance of Qu-CN-COF material
[0059] The photocatalytic H2 production experiment was conducted in a top-illuminated photoreactor (Pyrex glass) connected to a closed gas circulation system. Hydrogen production efficiency was calculated based on peak area. Experimental method: The organic framework photocatalytic material powders (1 mg) obtained in Examples 1-3 and Comparative Examples 1-2 were dispersed in 100 mL of a mixed aqueous solution containing 0.1 M ascorbic acid. A calculated amount of H2PtCl6 was dissolved in the suspension, and 5.0 wt.% Pt was deposited on the catalyst surface via photodeposition. The temperature was maintained at 283 K using circulating water, and the photocatalytic H2 evolution was evaluated using a 300 W xenon lamp (wavelength between 350 nm and 780 nm). Hydrogen production was measured using a gas chromatograph (GC) equipped with a thermal conductivity detector (TCD) and argon as the carrier gas. The photocatalytic hydrogen production results over 4 h are shown in Table 1.
[0060] Table 1 Photocatalytic hydrogen production
[0061]
[0062] As shown in Table 1, under the same Pt loading, the porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic materials obtained in Examples 1-3 of this invention exhibit excellent performance in photocatalytic hydrogen production tests when used as a support, achieving a hydrogen production of 1049.31 mmol·g within 4 hours. -1 When the materials obtained from Comparative Examples 1 and 2 are used as carriers, the photocatalytic hydrogen production performance decreases significantly.
[0063] The hydrogen production cycle performance of the porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic material obtained in Example 1 is as follows: Figure 8 As shown, it still maintains high hydrogen evolution catalytic activity after 24 hours of reaction and has good cycle stability.
[0064] Chemical stability test of Qu-CN-COF in Experiment 2
[0065] The porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalytic material prepared in Example 1 was sequentially dispersed in 12 mol / L hydrochloric acid and 14 mol / L sodium hydroxide aqueous solution at room temperature for 72 h each. After filtration, the filter cake was washed with water and tetrahydrofuran, dried, and characterized by powder X-ray diffraction.
[0066] The results are as follows Figure 9 As shown, the X-ray diffraction patterns of the porous crystalline quinoline-based organic framework photocatalyst material prepared in Example 1 remained almost unchanged before and after immersion in strong acid and strong alkali, indicating that the porous crystalline quinoline-based organic framework (Qu-CN-COF) photocatalyst material maintained its original topology and pore size and had good chemical stability.
[0067] The above descriptions are only the preferred embodiment of the application, not intended to limit the application and any modification, equivalent replacement and improvement made within the principle and technical scope of the application should be included in the protection scope of the application.
Claims
1. A porous crystalline quinoline-based organic framework photocatalytic material, characterized in that, The structural formula is:
2. The method of claim 1, wherein the porous crystalline quinoline-based organic framework photocatalytic material is prepared by the method comprising: The method comprises the following steps: (1) weighing the reaction monomer 1,3,6,8-tetra(4-formaldehyde phenyl) pyrene and p-phenylenediamine, adding a mixed solvent, mixing, adding a catalyst, and reacting at 100-150 DEG C for 24-72 hours under a nitrogen atmosphere, and then filtering, washing and drying to obtain an imine bond framework compound; (2) uniformly dispersing the imine bond framework compound and aromatic alkyne in a solvent, adding a catalyst, and reacting at 100-150 DEG C for 24-72 hours under a nitrogen atmosphere, and then filtering, washing and drying to obtain a porous crystalline quinoline-based organic framework photocatalytic material, denoted as Qu-CN-COF.
3. The method for preparing a porous crystalline quinoline-based organic framework photocatalytic material according to claim 2, characterized in that, The stoichiometric ratio of the reaction monomers 1,3,6,8-tetra(4-formaldehyde phenyl) pyrene and p-phenylenediamine is 1:2; the mixed solvent is o-dichlorobenzene and n-butanol, and the volume ratio of o-dichlorobenzene to n-butanol is 1:1-4:1; and the mass-volume ratio of the reaction monomers to the mixed solvent is 1 mg:30 μL.
4. The method for preparing a porous crystalline quinoline-based organic framework photocatalytic material according to claim 2, characterized in that, The catalyst in step (1) is a 6M acetic acid solution; and the catalyst in step (2) is boron trifluoride ether and tetrachloroquinone.
5. The method for preparing a porous crystalline quinoline-based organic framework photocatalytic material according to claim 2, characterized in that, The molar ratio of the imine bond framework material to aromatic alkyne is 1:1-3; and the molar ratio of boron trifluoride ether, tetrachloroquinone and aromatic alkyne is 1:1:1-1:1:
3.
6. The method for preparing a porous crystalline quinoline-based organic framework photocatalytic material according to claim 2, characterized in that, The aromatic alkyne in step (2) is 4-ethynylbenzonitrile, and the solvent is any one of toluene, acetone and carbon tetrachloride.
7. The method for preparing a porous crystalline quinoline-based organic framework photocatalytic material according to claim 2, characterized in that, The solvent used for washing is at least one of tetrahydrofuran and ethanol.
8. A porous crystalline quinoline-based organic framework photocatalytic material prepared by the preparation method of any one of claims 2-7.
9. Application of the porous crystalline quinoline-based organic framework photocatalytic material of claim 1 in photocatalytic hydrogen production.
10. Use according to claim 9, characterized in that, The porous crystalline quinoline-based covalent organic framework loaded with metal is used as a photocatalytic hydrogen production catalyst, and the metal elements include one or more of Cu, Pt, Ir, Pd, Ni, Co and Ru.