Phthalocyanine-based COF material with directional charge separation function and preparation method and application of phthalocyanine-based COF material

Abstract

The invention discloses a charge directional separation phthalocyanine-based COF (Covalent Organic Framework) material as well as a preparation method and application thereof, and belongs to the technical field of covalent organic framework materials. The structural formula of the charge directional separation phthalocyanine-based COF material is as shown in a formula (I), phthalocyanine is used as a framework, an AA stacked layered structure is formed, electrons are attracted by metal cores, in-plane charge transfer is reduced, out-of-plane charge transfer becomes a main channel for carrier transport, carrier directional separation transfer is generated, and the charge transfer efficiency is improved. And the carrier recombination rate is obviously reduced, and the photocatalytic hydrogen production efficiency is improved. Besides, the COF material prepared by the method has excellent stability and cannot be decomposed in water, acid, alkali and common organic solvents (such as methanol, acetone, tetrahydrofuran, N, N-dimethylformamide and the like). The charge directional separation phthalocyanine-based COF material prepared by the invention also has huge potential in application in the aspects of gas storage, sensing and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of covalent organic framework materials, and more particularly relates to a charge directional separation phthalocyanine-based COF material and a preparation method and application thereof. BACKGROUND

[0002] Covalent organic framework (COF) materials exhibit great potential in the fields of gas adsorption / separation, proton conduction, photocatalysis, electrocatalysis, energy storage, sensing and biological-related applications. In order to further improve the performance of the materials and expand the application scenarios, the development of new COF materials has always been a research hotspot. Due to the flexibility and designability of COF materials at the molecular level, a large number of combinations of available building blocks can derive COF materials with diverse structures and rich functions. Among them, the selection of building blocks with functionality, modifiability and stability is crucial to expand the structural and functional diversity of new COFs.

[0003] Phthalocyanine (Pc) is a synthetic tetrapyrrole compound with a planar macrocyclic 18π-electron conjugated system. Its unique electronic structure and photophysical properties provide an ideal platform for functional material design. The introduction of phthalocyanine units into the COF framework can achieve the advantage of complementation at the molecular level, i.e., the synergistic effect of the periodic porous network of COFs and the wide-spectrum light response characteristics of phthalocyanine, which not only expands the diversity of COFs in the topological structure dimension and functional integration, but also exhibits a significant "1+1>2" interface synergistic effect. At present, the research on phthalocyanine-based COFs (Pc-COFs) is heating up, and its design strategy has developed from simple monomer preparation to precise regulation of multi-level structures, and a variety of advanced materials with high specific surface area and excellent electrical conductivity have emerged. However, the existing research still has obvious limitations: (1) In the aspect of structural design, the reported Pc-COFs are mostly limited to the alternating assembly of single phthalocyanine units and simple connecting groups (such as benzene rings and triazines), and there is a lack of in-depth exploration of multi-metal center synergy or hybrid π-conjugated systems; (2) In the aspect of functional applications, although phthalocyanine molecules have photosensitive activity, the research on Pc-COFs mainly focuses on the fields of electrocatalytic CO2 reduction and oxygen evolution reaction (OER), biosensors and lithium ion battery electrode materials, and its application potential in the field of photocatalysis has not been fully tapped. The mechanism behind this phenomenon may be due to the energy level mismatch problem in the system: the energy level difference (ΔE≈1.4eV) between the highest occupied molecular orbital (HOMO, -5.2eV) of the phthalocyanine unit and the lowest unoccupied molecular orbital (LUMO, -3.8eV) of the COF framework hinders the transmission path of photo-generated carriers, thereby significantly reducing the interface charge separation efficiency. How to optimize the energy band matching will be the key breakthrough to unlock the photocatalytic performance of Pc-COFs. SUMMARY

[0004] The application aims to provide a charge directional separation phthalocyanine-based COF material, a preparation method and application thereof.

[0005] A charge directional separation phthalocyanine-based COF material has a structural formula of formula (I),

[0006]

[0007] wherein M=Ni, Cu, Co, Zn.

[0008] The charge directional separation phthalocyanine-based COF material is named as MPc-HID-COF; HID=5-Hydroxyisophthalaldehyde.

[0009] A preparation method of a charge directional separation phthalocyanine-based COF material comprises the following steps:

[0010] The octa-aminated metal phthalocyanine, 5-hydroxyisophthalaldehyde and solvent are uniformly mixed, vacuumized in liquid nitrogen, then heated, then filtered, washed, Soxhlet extracted and dried to obtain the charge directional separation phthalocyanine-based COF material.

[0011] The octa-aminated metal phthalocyanine is MPc-8NH2, M=Ni, Cu, Co or Zn.

[0012] Preferably, the mass ratio of the octa-aminated metal phthalocyanine and 5-hydroxyisophthalaldehyde is 1:(2-3).

[0013] Preferably, the mass ratio of the sum of the octa-aminated metal phthalocyanine and 5-hydroxyisophthalaldehyde and the solvent is 1:(10-50).

[0014] Preferably, the solvent is at least one of 1,3,5-trimethylbenzene, 1,4-dioxane, triethylamine, methanol, dichloromethane, N,N-dimethylformamide and tetrahydrofuran.

[0015] Preferably, the vacuum degree is below 10 Pa; the heating temperature is 60-130 DEG C and the time is 72-120 h.

[0016] The application also protects the application of the charge directional separation phthalocyanine-based COF material in photocatalytic hydrogen production.

[0017] Compared with the prior art, the application has the following advantages: the charge directional separation phthalocyanine-based COF material takes phthalocyanine as a skeleton to form an AA-stacked layered structure, the electrons are attracted by the metal nucleus, the in-plane charge transport is reduced, the out-of-plane charge transport becomes the main channel of carrier transport, the carrier directional separation transport is generated, the carrier recombination rate is obviously reduced, and the efficiency of photocatalytic hydrogen production is improved. In addition, the COF material prepared in the application has excellent stability and will not decompose in water, acid, alkali and common organic solvents (such as methanol, acetone, tetrahydrofuran, N,N-dimethylformamide and the like). The charge directional separation phthalocyanine-based COF material prepared in the application also has great potential in the fields of gas storage, sensing and the like. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The FTIR spectrum of the CuPc-HID-COF photocatalytic material prepared in Example 1.

[0019] Figure 2 The XRD pattern of the CuPc-HID-COF photocatalytic material prepared in Example 1.

[0020] Figure 3 The XPS pattern of the CuPc-HID-COF photocatalytic material prepared in Example 1, (a) is a full spectrum pattern, and (b) is an N1s spectrum pattern.

[0021] Figure 4 The scanning electron microscope image of the CuPc-HID-COF photocatalytic material prepared in Example 1.

[0022] Figure 5 The TEM pattern of the CuPc-HID-COF photocatalytic material prepared in Example 1.

[0023] Figure 6 The structure simulation pattern of the CuPc-HID-COF photocatalytic material prepared in Example 1 and the electron-hole transport schematic diagram.

[0024] Figure 7 The hydrogen production amount and cyclic hydrogen production performance pattern of the ZnPc-HID-COF photocatalytic material prepared in Example 4.

[0025] Figure 8 The hydrogen production performance comparison pattern of the MPc-HID-COF photocatalytic material prepared in Examples 1-4. DETAILED DESCRIPTION

[0026] Various exemplary embodiments of the present application will now be described in detail, with reference to the drawings and specific examples. The detailed description is not to be taken as limiting the present application, but rather as a description of certain aspects, features, and embodiments of the present application.

[0027] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. Additionally, for the purposes of the present application, ranges disclosed can be understood as being inclusive of the

[0028] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. Although preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present application. All documents mentioned herein are incorporated by reference to disclose and describe in detail the methods and / or materials which are related to the present application. In the case of conflict between the present specification and any document incorporated by reference, the present specification will control.

[0029] Many modifications and variations of this application can be made in the light of the above teachings without departing from the spirit and scope thereof, and it is to be understood that all such modifications and variations warrant the patentable subject matter under the patent laws. Other embodiments of the application will be apparent to those skilled in the art from consideration of the specification and practice of the application disclosed herein. The specification and examples given are exemplary only and are not intended to limit the scope of the application.

[0030] As used herein, the terms "comprise", "comprising", "include", "including", "have", "having" and the like are open-ended and do not exclude the presence of other elements or steps.

[0031] The present application will now be further described with reference to the following drawings and examples, which are intended to be illustrative only and not limiting.

[0032] Example 1

[0033] A method for preparing a charge-directed separation phthalocyanine-based COF material, comprising the following steps:

[0034] CuPc-8NH2 69.1 mg and 5-hydroxyisophthalaldehyde (HID) 39 mg were weighed into a 25 mL schlenk tube containing 1 mL 1,4-dioxane, 0.5 mL triethylamine and 3 mL 1,3,5-trimethylbenzene, and ultrasonically mixed for 30 min, vacuumed to 10 Pa in a liquid nitrogen bath, sealed, and then placed in a constant temperature oven for heat treatment, kept at 100 DEG C for 72 h, cooled to room temperature, filtered out the precipitate, washed twice with DMF and THF, centrifuged to separate the precipitate, and then subjected to Soxhlet extraction (24 h, solvent THF) to purify the sample to obtain the CuPc-HID-COF photocatalytic material.

[0035] As shown in Figure 1 and 2 , CuPc-8NH2 and 5-hydroxyisophthalaldehyde (HID) successfully underwent Schiff base reaction to obtain the charge orientation separation phthalocyanine-based COF material CuPc-HID-COF.

[0036] As shown in Figure 3 , it is the XPS spectrum of the CuPc-HID-COF photocatalytic material. It shows that the COF material synthesized in the application mainly contains C, N, O and Cu elements, wherein C, N and Cu are derived from the phthalocyanine monomer, and the O element is derived from the HID monomer. From the N1s spectrum, it can be known that the N in the COF material mainly exists in the form of C-N-Cu and C=N-C bonding.

[0037] As shown in Figure 4 , 5 , the CuPc-HID-COF photocatalytic material has good crystallinity.

[0038] As shown in Figure 6 , the charge orientation separation transport of the CuPc-HID-COF photocatalytic material can effectively reduce the recombination rate.

[0039] Example 2

[0040] A preparation method of a charge orientation separation phthalocyanine-based COF material, comprising the following steps:

[0041] Weigh 69.6 mg of nickel octaaminophthalocyanine (NiPc-8NH2) and 39 mg of 5-hydroxyisophthalaldehyde (HID) and add them to a 25 mL schlenk tube containing 2 mL of 1,4-dioxane and 3 mL of 1,3,5-mesitylene. Mix them evenly by ultrasonication for 30 minutes. After evacuating to 10 Pa in a liquid nitrogen bath, seal the tube mouth and heat it in a constant temperature oven at 80°C for 96 hours. After cooling to room temperature, filter out the precipitate with a funnel and wash it twice with methanol, DMF and dichloromethane respectively. After centrifugation and precipitating, the sample is purified by Soxhlet extraction (24 hours, THF is the solvent) to obtain NiPc-HID-COF photocatalytic material.

[0042] Example 3

[0043] A method for preparing a charge-directed separation phthalocyanine-based COF material comprises the following steps:

[0044] 69.1 mg of octaaminophthalocyanine cobalt (CoPc-8NH2) and 39 mg of 5-hydroxyisophthalaldehyde (HID) were weighed and added to a 25 mL schlenk tube containing 2 mL of 1,4-dioxane and 3 mL of 1,3,5-mesitylene. The mixture was mixed evenly by ultrasonication for 30 min. After evacuating to 10 Pa in a liquid nitrogen bath, the tube mouth was sealed and then placed in a constant temperature oven for heating treatment at 60 ° C for 72 h. After cooling to room temperature, the precipitate was filtered out with a funnel and washed twice with methanol and dichloromethane respectively. After centrifugation and precipitation, the sample was purified by Soxhlet extraction (24 h, THF was used as the solvent) to obtain the CoPc-HID-COF photocatalytic material.

[0045] Example 4

[0046] A method for preparing a charge-directed separation phthalocyanine-based COF material comprises the following steps:

[0047] Weigh 69.8 mg of octaaminophthalocyanine zinc (ZnPc-8NH2) and 39 mg of 5-hydroxyisophthalaldehyde (HID) and add them to a 25 mL schlenk tube containing 1 mL of 1,4-dioxane, 0.5 mL of triethylamine and 3 mL of 1,3,5-mesitylene. Ultrasonicate for 30 minutes to mix evenly. After evacuating to 10 Pa in a liquid nitrogen bath, seal the tube mouth and place it in a constant temperature oven for heating treatment at 80°C for 120 hours. After cooling to room temperature, filter out the precipitate with a funnel and wash it twice with methanol, DMF and THF respectively. After centrifugation and precipitate separation, Soxhlet extraction (24 hours, THF as solvent) is performed to purify the sample to obtain ZnPc-HID-COF photocatalytic material.

[0048] Zinc octaaminophthalocyanine reference: Unveiling Electronic Properties in Metal-Phthalocyanine-based Pyrazine-linked Conjugated Two-Dimensional Covalent Organic Frameworks to prepare.

[0049] Example 5

[0050] A method for preparing a charge-oriented separation phthalocyanine-based COF material, comprising the following steps:

[0051] Weigh 69.1 mg of copper octaaminophthalocyanine (CuPc-8NH2) and 39 mg of 5-hydroxyisophthalaldehyde (HID) into a 25 mL schlenk tube containing 1 mL of 1,4-dioxane, 0.5 mL of triethylamine and 3 mL of 1,3,5-trimethylbenzene, ultrasonic for 30 min to mix uniformly, vacuumize to 10 Pa in a liquid nitrogen bath, then seal the tube mouth, then place it in a constant temperature oven for heat treatment, keep at 130°C for 72 h, cool to room temperature, filter out the precipitate with a funnel, wash twice with DMF and THF respectively, centrifuge the precipitate, then perform sample purification by Soxhlet extraction (24 h, solvent THF) to obtain the CuPc-HID-COF photocatalytic material.

[0052] Effect example

[0053] Photocatalytic experiment: take 10 mg of MPc-HID-COF material prepared in examples 1-5 respectively and place it in a 50 mL quartz reaction bottle, add 12 mL of deionized water and 8 mL of methanol (hole sacrificial agent), replace the internal air with Ar gas during stirring, then assemble the reaction system, irradiate from the bottom of the reaction bottle with a xenon lamp with a 420 nm cutoff filter, detect the H2 produced by the system by gas chromatography, take samples every half hour, count the results of 5 times, then linearly fit the results of 5 times to obtain the hydrogen production amount. After the reaction, replace the gas in the bottle with Ar gas for cyclic hydrogen production performance test.

[0054] The results are shown in Figure 7 , 8 and Table 1.

[0055] Table 1

[0056] Hydrogen production (mmol / g) Retention of hydrogen production after 6 cycles / % Example 1 69.5 95.5 Example 2 61.5 94.6 Example 3 45.6 93,2 Example 4 96.8 95.7 Example 5 68.8 95.3

[0057] As Figure 7 shown, the ZnPc-HID-COF photocatalytic material prepared in example 4 has excellent stability and high visible light catalytic activity.

[0058] like Figure 8 As shown, the MPc-HID-COF photocatalytic materials prepared in Examples 1-4 have excellent carrier directional separation and transmission performance under visible light excitation, and exhibit high catalytic activity and good stability in the visible light water decomposition hydrogen production test.

[0059] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A charge-directed separation phthalocyanine-based COF material, characterized in that: The structural formula is formula (I), Wherein M=one of Ni, Cu, Co, and Zn.

2. The method for preparing the charge-oriented separation phthalocyanine-based COF material according to claim 1, characterized in that: The steps include: Octaamino metal phthalocyanine, 5-hydroxyisophthalaldehyde and solvent are mixed evenly, vacuumed in liquid nitrogen, then heat-treated, and finally filtered, washed, Soxhlet extracted and dried to obtain a charge-oriented separation phthalocyanine-based COF material.

3. The method for preparing the charge-oriented separation phthalocyanine-based COF material according to claim 2, characterized in that: The molar ratio of the octaamino metal phthalocyanine to 5-hydroxyisophthalaldehyde is 1:(2-3).

4. The method for preparing the charge-oriented separation phthalocyanine-based COF material according to claim 2, characterized in that: The mass ratio of the sum of the masses of the octaamino metal phthalocyanine and 5-hydroxyisophthalaldehyde to the solvent is 1:(10-50).

5. The method for preparing the charge-oriented separation phthalocyanine-based COF material according to claim 2, characterized in that: The solvent is at least one of 1,3,5-mesitylene, 1,4-dioxane, triethylamine, methanol, dichloromethane, N,N-dimethylformamide, and tetrahydrofuran.

6. The method for preparing the charge-directed separation phthalocyanine-based COF material according to claim 2, characterized in that: The vacuum degree is below 10 Pa; the temperature of the heating treatment is 60-130° C., and the time is 72-120 hours.

7. Use of the charge-directed separation phthalocyanine-based COF material according to claim 1 in photocatalytic hydrogen production.

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