Spiral dislocation stacked imine covalent organic framework materials, their preparation methods and applications

Abstract

This invention relates to a method for preparing a helical dislocation-stacking imine covalent organic framework material, comprising the steps of preparing an imine covalent oligomer and preparing the helical dislocation-stacking imine covalent organic framework material. This invention also provides the helical dislocation-stacking imine covalent organic framework material obtained by the aforementioned method and its application in light-absorbing semiconductor materials. The preparation method provided by this invention is simple, universal, and easy to implement, and yields an imine covalent organic framework material with a helical dislocation-stacking structure. The material has a well-defined structure and good crystallinity, representing a novel topological structure with promising potential applications in the optoelectronic field.

Description

Technical Field

[0001] This invention relates to the field of novel topological material preparation technology, specifically to a method for preparing covalent organic framework materials. Background Technology

[0002] Two-dimensional covalent organic frameworks (2D COFs) are a class of organic crystalline semiconductors composed of lightweight organic elements such as C, H, N, O, and B. They possess advantages such as large specific surface area, long-range order, and tunable topological and chemical structures, showing promising applications in photoelectric detection and heterogeneous catalysis. However, although 2D COF materials exhibit distinct crystal structures, most currently belong to eclipsed AA stacking, with a small number belonging to staggered AB stacking. Therefore, the development of 2D COFs with novel topological structures has been an important branch of framework chemistry research, which can greatly enhance the tunability of the photoelectric properties of these materials, thereby further enriching their applications in photoelectric detection and catalysis.

[0003] However, the non-covalent interlayer interactions of 2D COFs are often elusive, limiting the tunability of their topology to monomer design strategies. Generally, spatial or π-electronic customization strategies can give specific 2D COFs different interlayer spacings. For example, non-planar substituents (such as alkyl chains), hydrogen bonders (such as hydroxyl and methoxy groups), and electron density modulating groups (such as fluorine substituents) are often pre-grafted to control their interlayer spacing, thereby modulating their charge transport dynamics. Furthermore, sensitive interlayer π interactions can also be influenced by specific physical stimuli, such as gas or solvent permeation post-treatment, which may force some 2D COFs to undergo structural rearrangement. However, monomer design strategies inevitably alter the COF structure; for post-treatment rearrangement strategies, framework rearrangements may not be sustainable in the absence of stimuli. Therefore, controlling the topology and photoelectric coupling of 2D COFs without altering their structure remains a significant challenge. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by providing a 2D imine COFs material with tunable topology and a spiral dislocation stacking structure, and to apply the 2D imine COFs material to a spiral dislocation stacked imine covalent organic framework material in light-absorbing semiconductor materials, as well as its preparation method and application.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a method for preparing a spiral dislocation-stacking imine covalent organic framework material, comprising the following steps:

[0006] Step 1: Preparation of imine covalent oligomers:

[0007] Equal molar amounts of aldehyde and amine monomer molecules are ultrasonically dispersed in a two-component organic solvent of any volume ratio to form a monomer molecule solution with a molar concentration of 0.02–10 mol / L. Subsequently, an organic acid catalyst is added, and the monomer is directly polymerized at room temperature to form an imine covalent oligomer.

[0008] The volume ratio of the two-component organic solvent to the organic acid catalyst is 0.5–3.

[0009] Step 2: Preparation of spiro dislocation-stacking imine covalent organic framework materials:

[0010] The imine covalent oligomer prepared in step one was crystallized at 25–120°C for 6–96 h. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 10–14 h to obtain an imine covalent organic framework material with a spiral dislocation stacking structure.

[0011] Furthermore, in the precursor of the imine covalent oligomer, the ratio of the total aldehyde group in the aldehyde precursor to the total amino group in the amine precursor is 1 / 1.

[0012] Furthermore, the aldehyde precursor is one of tris(4-formylphenyl)amine, 1,3,5-tris(4-carboxyphenyl)benzene, and 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine.

[0013] Furthermore, the amine precursor is one of tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.

[0014] Furthermore, the two-component organic solvent is one of the following combinations in any volume ratio: n-butanol and o-dichlorobenzene, ethanol and o-dichlorobenzene, dioxane and mesitylene.

[0015] Furthermore, the organic acid catalyst mentioned in step one is one of formic acid, acetic acid, and trifluoroacetic acid.

[0016] The present invention also provides a spiral dislocation-stacking imine covalent organic framework material obtained by the preparation method described above, wherein at least one of the aldehyde or amine monomer molecules in the imine covalent organic framework material has a propeller structure, and the spiral dislocation stacking structure in the imine covalent organic framework prepared from different aldehyde and amine monomer molecules remains unchanged.

[0017] The spiral dislocation stacking structure refers to a spiral dislocation lattice stripe structure with a crystal plane spacing of 0.3 to 0.5 nm.

[0018] The present invention also provides an application of the imine covalent organic framework material in light-absorbing semiconductor materials, particularly in the field of photocatalytic water splitting for hydrogen production regulated by photoelectric coupling.

[0019] Furthermore, the imine covalent organic framework material has a light absorption band gap of 2–3 eV and a photocatalytic hydrogen production rate of 50–100 mmol / g / h.

[0020] The beneficial effects of this invention are:

[0021] (1) The imine covalent organic framework material prepared by this invention has the characteristics of "spiral dislocation stacking" and good crystallinity, and has great application prospects in the field of photoelectro-photonic heterogeneous catalysis.

[0022] (2) The preparation method provided by the present invention is simple and mild.

[0023] (3) The present invention can prepare a variety of spiral dislocation stacked imine covalent organic framework materials in a green, simple, efficient and universal manner. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the helical dislocation stacking structure of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1 of the present invention;

[0025] Figure 2 The powder X-ray diffraction (PXRD) spectrum of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1 of this invention is shown.

[0026] Figure 3 This is a high-resolution transmission electron microscope (HRTEM) image of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1 of the present invention.

[0027] Figure 4 The image shows the UV / Vis diffuse reflectance spectrum (UV / Vis-DRS) of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1 of this invention.

[0028] Figure 5 The image shows the photocatalytic water splitting effect of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1. Detailed Implementation

[0029] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0030] To achieve the above objectives, the present invention provides the following specific embodiments:

[0031] Example 1: A method for preparing a spiral dislocation-stacked imine covalent organic framework material, comprising the following steps:

[0032] Step 1: Preparation of imine covalent oligomers:

[0033] Equal molar amounts of aldehyde and amine monomer molecules are ultrasonically dispersed in a two-component organic solvent of any volume ratio to form a monomer molecule solution with a molar concentration of 0.02–10 mol / L. Subsequently, an organic acid catalyst is added, and the monomer is directly polymerized at room temperature to form an imine covalent oligomer.

[0034] The volume ratio of the two-component organic solvent to the organic acid catalyst is 0.5–3.

[0035] In the precursors of imine covalent oligomers, the ratio of the total aldehyde group in the aldehyde precursor to the total amino group in the amine precursor is 1 / 1.

[0036] The aldehyde precursor is one of tris(4-formylphenyl)amine, 1,3,5-tris(4-carboxyphenyl)benzene, or 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine.

[0037] The amine precursor is one of tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, or 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.

[0038] The two-component organic solvent is one of the following combinations in any volume ratio: n-butanol and o-dichlorobenzene, ethanol and o-dichlorobenzene, or dioxane and mesitylene.

[0039] The organic acid catalyst is one of formic acid, acetic acid, or trifluoroacetic acid.

[0040] Step 2: Preparation of spiro dislocation-stacking imine covalent organic framework materials:

[0041] The imine covalent oligomer prepared in step one was crystallized at 25–120°C for 6–96 h. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 10–14 h to obtain an imine covalent organic framework material with a spiral dislocation stacking structure.

[0042] Example 2: This invention also provides a method for preparing a helical dislocation-stacking imine covalent organic framework material in which at least one monomer molecule has a propeller structure, and the helical dislocation stacking structure in the imine covalent organic framework prepared from different aldehyde and amine monomer molecules remains unchanged. The helical dislocation stacking structure refers to a helical dislocation lattice fringe structure with a crystal plane spacing of 0.3–0.5 nm.

[0043] To further illustrate the solution and effects of the present invention, the following experimental examples are provided:

[0044] Experimental Example 1: Figure 1-4 As shown, the preparation of a spiro dislocation-stacking imine covalent organic framework (SAA-COF1) is as follows:

[0045] (1) 0.04 mmol of tris(4-formylphenyl)amine and 0.04 mmol of tris(4-aminophenyl)amine monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of acetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0046] (2) The imine covalent oligomer prepared in step one was placed at 60°C and crystallized for 12 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF1 with a spiral dislocation stacking structure.

[0047] like Figure 1-3 As shown, Figure 1 This is the specific spiral dislocation stacking structure of the imine covalent organic framework (SAA-COF1) prepared in Experiment Example 1 of this experiment;

[0048] Figure 2 The results show that the XRD pattern of the present invention is in perfect agreement with the theoretically simulated spiral dislocation stack, which is a spiral dislocation stack structure.

[0049] Figure 3 The figure shows the obvious crystal structure of COF obtained in Experiment Example 1, with spiral dislocation lattice fringes having a plane spacing of 0.34 nm.

[0050] Experimental Example 2: Preparation of SAA-COF2:

[0051] (1) 0.04 mmol of tris(4-formylphenyl)amine and 0.04 mmol of 1,3,5-tris(4-aminophenyl)benzene monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of acetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0052] (2) The imine covalent oligomer prepared in step one was placed at 60°C and crystallized for 12 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF2 with a spiral dislocation stacking structure.

[0053] Experimental Example 3: Preparation of SAA-COF3:

[0054] (1) 0.04 mmol of tris(4-formylphenyl)amine and 0.04 mmol of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of acetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0055] (2) The imine covalent oligomer prepared in step one was placed at 60°C and crystallized for 12 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF3 with a spiral dislocation stacking structure.

[0056] Experimental Example 4: Preparation of SAA-COF4:

[0057] (1) 0.04 mmol of 1,3,5-tris(4-carboxyphenyl)benzene and 0.04 mmol of tris(4-aminophenyl)amine monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of acetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0058] (2) The imine covalent oligomer prepared in step one was placed at 100°C and crystallized for 24 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF4 with a spiral dislocation stacking structure.

[0059] Experimental Example 5: Preparation of SAA-COF5:

[0060] (1) 0.04 mmol of 1,3,5-tris(4-carboxyphenyl)benzene and 0.04 mmol of 1,3,5-tris(4-aminophenyl)benzene monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of acetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0061] (2) The imine covalent oligomer prepared in step one was placed at 100°C and crystallized for 24 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF5 with a spiral dislocation stacking structure.

[0062] Experimental Example 6: Preparation of SAA-COF6:

[0063] (1) 0.04 mmol of 1,3,5-tris(4-carboxyphenyl)benzene and 0.04 mmol of 1,3,5-tris(4-aminophenyl)benzene monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of acetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0064] (2) The imine covalent oligomer prepared in step one was placed at 100°C and crystallized for 24 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF6 with a spiral dislocation stacking structure.

[0065] Experimental Example 7: Preparation of SAA-COF7:

[0066] (1) 0.04 mmol of 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine and 0.04 mmol of tris(4-aminophenyl)amine monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of trifluoroacetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0067] (2) The imine covalent oligomer prepared in step one was placed at 100°C and crystallized for 24 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF7 with a spiral dislocation stacking structure.

[0068] Experimental Example 8: Preparation of SAA-COF8:

[0069] (1) 0.04 mmol of 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine and 0.04 mmol of 1,3,5-tris(4-aminophenyl)benzene monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of trifluoroacetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0070] (2) The imine covalent oligomer prepared in step one was placed at 100°C and crystallized for 24 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF8 with a spiral dislocation stacking structure.

[0071] Experimental Example 9: Preparation of SAA-COF9:

[0072] (1) 0.04 mmol of 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine and 0.04 mmol of 1,3,5-tris(4-aminophenyl)benzene monomer molecules were ultrasonically dispersed in 1.5 mL of n-butanol / 0.5 mL of o-dichlorobenzene combined solvent, and then 0.5 mL of trifluoroacetic acid was added as a catalyst. The mixture was directly polymerized at room temperature to form an imine covalent oligomer.

[0073] (2) The imine covalent oligomer prepared in step one was placed at 100°C and crystallized for 24 hours. The precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF9 with a spiral dislocation stacking structure.

[0074] Example 3: As Figure 4 , Figure 5 As shown, this invention also provides an application of an imine covalent organic framework material in light-absorbing semiconductor materials, particularly in the field of photocatalytic water splitting for hydrogen production regulated by photoelectric coupling. The imine covalent organic framework material has a light absorption band gap of 2–3 eV and a photocatalytic hydrogen production rate of 50–100 mmol / g / h.

[0075] Figure 4 The image shows the imine covalent organic framework (SAA-COF1) prepared in Example 1. As can be seen from the figure, it is a semiconductor material with broad light absorption and a band gap of 2.26 eV.

[0076] Figure 5 The figure shows the photocatalytic water splitting hydrogen production effect of the imine covalent organic framework (SAA-COF1) prepared in Experiment Example 1. As can be seen from the figure, SAA-COF1 can photocatalytically split water and produce obvious hydrogen bubbles. Under the conditions of 0.1M ascorbic acid aqueous solution as sacrificial agent and 1.5wt% Pt as cocatalyst, the photocatalytic hydrogen production rate of SAA-COF1 is 78 mmol / g / h and can work continuously and stably for 24 hours.

[0077] In summary, this invention yields an imine covalent organic framework material with a spiral dislocation stacking structure. This structure is well-defined, exhibits good crystallinity, and represents a novel topological structure. Furthermore, the preparation method provided by this invention is simple, universal, and easy to implement, possessing promising potential applications in the optoelectronic field.

[0078] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a spiral dislocation-stacking imine covalent organic framework material, characterized in that, Includes the following steps: Step 1: Preparation of imine covalent oligomers: Equal molar amounts of aldehyde and amine monomer molecules are ultrasonically dispersed in a two-component organic solvent of any volume ratio to form a monomer molecule solution with a molar concentration of 0.02–10 mol / L. Subsequently, an organic acid catalyst is added, and the monomer is directly polymerized at room temperature to form an imine covalent oligomer. The volume ratio of the two-component organic solvent to the organic acid catalyst is 0.5–3. Step 2: Preparation of spiro dislocation-stacking imine covalent organic framework materials: The imine covalent oligomer prepared in step one was crystallized at 25–120 °C for 6–96 h. The resulting precipitate was washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate was then dried at 80 °C for 10–14 h to obtain a helical dislocation-packed imine covalent organic framework material. The helical dislocation-packed structure refers to a helical dislocation lattice fringe structure with a crystal plane spacing of 0.34 nm. Among them, at least one of the aldehyde or amine monomer molecules in the imine covalent organic framework material has a propeller structure, and the spiral dislocation stacking structure in the imine covalent organic framework prepared from different aldehyde and amine monomer molecules remains unchanged.

2. The method for preparing the helical dislocation-stacking imine covalent organic framework material as described in claim 1, characterized in that, In the precursor of the imine covalent oligomer, the ratio of the total aldehyde group in the aldehyde precursor to the total amino group in the amine precursor is 1 / 1.

3. The method for preparing the helical dislocation-stacking imine covalent organic framework material as described in claim 2, characterized in that, The aldehyde precursor is one of tris(4-formylphenyl)amine, 1,3,5-tris(4-carboxyphenyl)benzene, and 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine.

4. The method for preparing the helical dislocation-stacking imine covalent organic framework material as described in claim 2, characterized in that, The amine precursor is one of tris(4-aminophenyl)amine, 1,3,5-tris(4-aminophenyl)benzene, and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.

5. The method for preparing the helical dislocation-stacking imine covalent organic framework material as described in claim 1, characterized in that, The two-component organic solvent is one of the following combinations in any volume ratio: n-butanol and o-dichlorobenzene, ethanol and o-dichlorobenzene, or dioxane and mesitylene.

6. The method for preparing the helical dislocation-stacking imine covalent organic framework material according to any one of claims 1-5, characterized in that, The organic acid catalyst mentioned in step one is one of formic acid, acetic acid, and trifluoroacetic acid.

7. An application of a spirodislocation-stacking imine covalent organic framework material obtained by the preparation method described in claim 6, characterized in that, Application of the material in light-absorbing semiconductor materials.

8. The application of the spiral dislocation-stacking imine covalent organic framework material as described in claim 7, characterized in that, Application of the material in the field of photocatalytic water splitting for hydrogen production under photoelectric coupling regulation.

9. The application of the spiral dislocation-stacking imine covalent organic framework material as described in claim 7, characterized in that, The imine covalent organic framework material has a light absorption band gap of 2–3 eV and a photocatalytic hydrogen production rate of 50–100 mmol / g / h.

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