Spiral dislocation stacked imine covalent organic framework material as well as preparation method and application thereof

Abstract

The invention relates to a preparation method of a spiral dislocation stacked imine covalent organic framework material. The preparation method comprises the steps of preparing an imine covalent oligomer and preparing the spiral dislocation stacked imine covalent organic framework material. The invention also provides the spiral dislocation accumulation imine covalent organic framework material obtained by the preparation method and application of the spiral dislocation accumulation imine covalent organic framework material in light absorption semiconductor materials. The preparation method provided by the invention is simple, convenient, universal and easy to implement, and the imine covalent organic framework material with the spiral dislocation stacking structure is obtained, is clear in material structure and good in crystallinity, is a novel topological structure, and has a good potential application prospect in the photoelectric field.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of new topological materials, and in particular to a preparation method of a covalent organic framework material. Background Art

[0002] Two-dimensional covalent organic frameworks (2D Covalent Organic Framework, 2D COFs) are a class of organic crystalline semiconductors composed of light elements such as organic C, H, N, O and B. They have the advantages of large specific surface area, long-range order, and adjustable topology and chemical structure. They have good application prospects in the fields of photoelectric detection and heterogeneous catalysis. However, although 2D COFs materials have obvious crystal structures, most of them currently belong to AA stacking (eclipsed AA stacking), and a small amount belongs to AB stacking (staggered stacking). Therefore, the development of 2D COFs with new topological structures has always been an important branch of framework chemistry research, which can greatly promote the adjustability of the photoelectric properties of this type of material, thereby further enriching its application in fields such as photoelectric detection and catalysis.

[0003] However, the interlayer non-covalent interactions of 2DCOFs are usually elusive, which limits the tunability of their topological structures to monomer design strategies. In general, spatial or π-electron tailoring strategies can enable specific 2D COFs to have different interlayer spacings. For example, non-planar substituents (such as alkyl chains), hydrogen bonders (such as hydroxyl and methoxy groups), and electron density regulating groups (such as fluorine substituents) are usually pre-grafted to control their interlayer spacing and thus regulate their charge transfer dynamics. In addition, sensitive interlayer π interactions can also be affected by specific physical stimuli, such as gas or solvent infiltration post-treatment, which may force some 2D COFs to undergo structural reorganization. However, for the monomer design strategy, the structure of COF will inevitably be changed; for the post-treatment rearrangement strategy, the framework rearrangement may not be preserved in the absence of stimulation. Therefore, without changing the structure of COFs, the regulation of the topological structure of 2D COFs and their photoelectric coupling still faces great challenges. Summary of the invention

[0004] The purpose of the present invention is to avoid the shortcomings of the prior art and provide a 2D imine COFs material that can realize adjustable 2D COFs topological structure and prepare a screw dislocation stacking structure, and apply the 2D imine COFs material to the screw dislocation stacking imine covalent organic framework material in light-absorbing semiconductor materials and its preparation method and application.

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

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

[0007] Equal moles 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 to 10 mol / L, and then an organic acid catalyst is added to directly polymerize at room temperature to form an imine covalent oligomer;

[0008] Wherein, the volume ratio of the two-component organic solvent to the organic acid catalyst is 0.5 to 3;

[0009] Step 2: Preparation of screw dislocation stacking imine covalent organic framework material:

[0010] The imine covalent oligomer prepared in step 1 is placed at 25-120° C. for crystallization for 6-96 hours, and the formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80° C. for 10-14 hours to obtain an imine covalent organic framework material with a screw dislocation stacking structure.

[0011] Furthermore, in the precursor of the imine covalent oligomer, the ratio of the total amount of aldehyde groups in the aldehyde precursor to the total amount of amino groups 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 a combination of n-butanol and o-dichlorobenzene, ethanol and o-dichlorobenzene, and dioxane and mesitylene in any volume ratio.

[0015] Furthermore, the organic acid catalyst in step 1 is one of formic acid, acetic acid and trifluoroacetic acid.

[0016] The present invention also provides a screw dislocation stacking imine covalent organic framework material obtained by the preparation method, wherein the aldehyde or amine monomer molecules of the imine covalent organic framework material have at least one monomer molecule propeller structure, and the screw dislocation stacking structure in the imine covalent organic framework prepared from different aldehyde and amine monomer molecules does not change.

[0017] The screw dislocation stacking structure refers to a screw dislocation lattice fringe 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, especially in the field of photocatalytic water decomposition and hydrogen production regulated by photoelectric coupling.

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

[0020] The beneficial effects of the present invention are:

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

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

[0023] (3) The present invention can prepare a variety of screw dislocation stacking imine covalent organic framework materials in a green, simple, efficient and universal manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the screw dislocation stacking structure of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1 of the present invention;

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

[0026] Figure 3 A high resolution transmission electron microscopy (HRTEM) image of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1 of the present invention;

[0027] Figure 4 It is a UV / Vis diffuse reflectance spectrum (UV / Vis-DRS) diagram of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1 of the present invention;

[0028] Figure 5 This is a diagram showing the photocatalytic water decomposition and hydrogen production effect of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1. DETAILED DESCRIPTION

[0029] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0030] In order to achieve the above object, the present invention provides the following specific implementation methods:

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

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

[0033] Equal moles 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 to 10 mol / L, and then an organic acid catalyst is added to directly polymerize at room temperature to form an imine covalent oligomer;

[0034] Wherein, the volume ratio of the two-component organic solvent to the organic acid catalyst is 0.5 to 3;

[0035] In the precursor of the imine covalent oligomer, the ratio of the total amount of aldehyde groups in the aldehyde precursor to the total amount of amino groups 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, and 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, and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine.

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

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

[0040] Step 2: Preparation of screw dislocation stacking imine covalent organic framework material:

[0041] The imine covalent oligomer prepared in step 1 is placed at 25-120° C. for crystallization for 6-96 hours, and the formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80° C. for 10-14 hours to obtain an imine covalent organic framework material with a screw dislocation stacking structure.

[0042] Embodiment 2: The present invention also provides a method for preparing a screw dislocation stacking imine covalent organic framework material, wherein at least one monomer molecule has a propeller structure in the aldehyde or amine monomer molecules, and the screw dislocation stacking structure in the imine covalent organic framework prepared from different aldehyde and amine monomer molecules does not change. The screw dislocation stacking structure refers to a screw dislocation lattice fringe structure with a crystal plane spacing of 0.3 to 0.5 nm.

[0043] In order to further illustrate the scheme and effect of the present invention, the present invention provides the following experimental examples:

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

[0045] (1) 0.04 mmol of tri(4-formylphenyl)amine and 0.04 mmol of tri(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 and directly polymerized at room temperature to form imine covalent oligomers.

[0046] (2) The imine covalent oligomer prepared in step 1 is placed at 60°C for crystallization for 12 hours, and the formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF1 with a screw dislocation stacking structure.

[0047] like Figure 1-3 As shown, Figure 1 It is the specific screw dislocation stacking structure of the imine covalent organic framework (SAA-COF1) prepared in Experimental Example 1;

[0048] Figure 2 It is shown that the XRD of the screw dislocation stacking obtained by the present invention is completely consistent with that obtained by theoretical simulation, that is, it is a screw dislocation stacking structure.

[0049] Figure 3 The COF obtained in Experimental Example 1 has a distinct crystal structure and screw dislocation lattice fringes with a lattice spacing of 0.34 nm.

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

[0051] (1) 0.04 mmol of tri(4-formylphenyl)amine and 0.04 mmol of 1,3,5-tri(4-aminophenyl)benzene monomer molecules were ultrasonically dispersed in a 1.5 mL n-butanol / 0.5 mL o-dichlorobenzene solvent combination, and then 0.5 mL of acetic acid was added as a catalyst for direct polymerization at room temperature to form imine covalent oligomers.

[0052] (2) The imine covalent oligomer prepared in step 1 is placed at 60°C for crystallization for 12 hours, and the formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF2 with a screw dislocation stacking structure.

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

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

[0055] (2) The imine covalent oligomer prepared in step 1 is placed at 60°C for crystallization for 12 hours, and the formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF3 with a screw dislocation stacking structure.

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

[0057] (1) 0.04 mmol of 1,3,5-tri(4-carboxyphenyl)benzene and 0.04 mmol of tri(4-aminophenyl)amine monomer molecules were ultrasonically dispersed in a 1.5 mL n-butanol / 0.5 mL o-dichlorobenzene solvent combination, and then 0.5 mL of acetic acid was added as a catalyst to directly polymerize at room temperature to form imine covalent oligomers;

[0058] (2) The imine covalent oligomer prepared in step 1 is placed at 100°C for crystallization for 24 hours. The formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF4 with a screw dislocation stacking structure.

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

[0060] (1) 0.04 mmol of 1,3,5-tri(4-carboxyphenyl)benzene and 0.04 mmol of 1,3,5-tri(4-aminophenyl)benzene monomer molecules were ultrasonically dispersed in a 1.5 mL n-butanol / 0.5 mL o-dichlorobenzene solvent combination, and then 0.5 mL of acetic acid was added as a catalyst to directly polymerize at room temperature to form imine covalent oligomers;

[0061] (2) The imine covalent oligomer prepared in step 1 is placed at 100°C for crystallization for 24 hours, and the formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF5 with a screw dislocation stacking structure.

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

[0063] (1) 0.04 mmol of 1,3,5-tri(4-carboxyphenyl)benzene and 0.04 mmol of 1,3,5-tri(4-aminophenyl)benzene monomer molecules were ultrasonically dispersed in a 1.5 mL n-butanol / 0.5 mL o-dichlorobenzene solvent combination, and then 0.5 mL of acetic acid was added as a catalyst to directly polymerize at room temperature to form imine covalent oligomers;

[0064] (2) The imine covalent oligomer prepared in step 1 is placed at 100°C for crystallization for 24 hours. The formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF6 with a screw 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 to directly polymerize at room temperature to form imine covalent oligomers;

[0067] (2) The imine covalent oligomer prepared in step 1 is placed at 100°C for crystallization for 24 hours. The formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF7 with a screw 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 a 1.5 mL n-butanol / 0.5 mL o-dichlorobenzene solvent combination, followed by the addition of 0.5 mL of trifluoroacetic acid as a catalyst, and direct polymerization was performed at room temperature to form imine covalent oligomers;

[0070] (2) The imine covalent oligomer prepared in step 1 is placed at 100°C for crystallization for 24 hours. The formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF8 with a screw 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 a 1.5 mL n-butanol / 0.5 mL o-dichlorobenzene solvent combination, followed by the addition of 0.5 mL of trifluoroacetic acid as a catalyst, and direct polymerization was performed at room temperature to form imine covalent oligomers;

[0073] (2) The imine covalent oligomer prepared in step 1 is placed at 100°C for crystallization for 24 hours. The formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80°C for 12 hours to obtain the imine covalent organic framework material SAA-COF9 with a screw dislocation stacking structure.

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

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

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

[0077] In summary, the present invention obtains an imine covalent organic framework material with a screw dislocation stacking structure, and the structure is clear and has good crystallinity, which is a novel topological structure. In addition, the preparation method provided by the present invention is simple, universal and easy to implement, and has good potential application prospects in the field of optoelectronics.

[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 principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a screw dislocation stacking imine covalent organic framework material, characterized in that: The steps include: Step 1: Preparation of imine covalent oligomers: Equal moles 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 to 10 mol / L, and then an organic acid catalyst is added to directly polymerize at room temperature to form an imine covalent oligomer; Wherein, the volume ratio of the two-component organic solvent to the organic acid catalyst is 0.5 to 3; Step 2: Preparation of screw dislocation stacking imine covalent organic framework material: The imine covalent oligomer prepared in step 1 is placed at 25-120° C. for crystallization for 6-96 hours, and the formed precipitate is washed with tetrahydrofuran to remove unreacted monomers. The collected precipitate is then dried at 80° C. for 10-14 hours to obtain an imine covalent organic framework material with a screw dislocation stacking structure.

2. The method for preparing the screw dislocation stacking imine covalent organic framework material according to claim 1, characterized in that: In the precursor of the imine covalent oligomer, the ratio of the total amount of aldehyde groups in the aldehyde precursor to the total amount of amino groups in the amine precursor is 1 / 1.

3. The method for preparing the screw dislocation stacking imine covalent organic framework material according to 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 screw dislocation stacking imine covalent organic framework material according to 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 screw dislocation stacking imine covalent organic framework material according to claim 1, characterized in that: The two-component organic solvent is one of a combination of n-butanol and o-dichlorobenzene, ethanol and o-dichlorobenzene, and dioxane and mesitylene in any volume ratio.

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

7. A screw dislocation stacking imine covalent organic framework material obtained by the preparation method according to claims 1-6, characterized in that: Among the aldehyde or amine monomer molecules of the imine covalent organic framework material, at least one monomer molecule has a propeller structure, and the screw dislocation stacking structure in the imine covalent organic framework prepared from different aldehyde and amine monomer molecules does not change.

8. The screw dislocation stacking imine covalent organic framework material according to claim 7, characterized in that: The screw dislocation stacking structure refers to a screw dislocation lattice fringe structure with a crystal plane spacing of 0.3 to 0.5 nm.

9. An application of the screw dislocation stacking imine covalent organic framework material as claimed in claim 7, characterized in that: The application of the material in light-absorbing semiconductor materials is particularly applied in the field of photocatalytic water decomposition and hydrogen production regulated by photoelectric coupling.

10. The use of the screw dislocation stacking imine covalent organic framework material as claimed in claim 9, characterized in that: The light absorption band gap of the imine covalent organic framework material is 2 to 3 eV, and the photocatalytic hydrogen production rate is 50 to 100 mmol / g / h.

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