Perylene bisimide-based COF material as well as preparation method and application thereof in photocatalysis

Abstract

The invention discloses a perylene bisimide-based COF material as well as a preparation method and application thereof in photocatalysis. The material is prepared by taking perylene bisimide as an electron donor and a monomer with high hydrogen evolution catalytic activity as an electron acceptor and adopting a traditional COF synthesis technology, and has double active sites required by full water splitting, a wide light absorption range and excellent charge separation capacity. The PDI-COF catalyst realizes low-cost and high-efficiency photocatalytic full water splitting hydrogen production under visible light, and has huge potential in the field of commercial solar hydrogen production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of photocatalysis, and particularly relates to a perylene imide-based COF material, a preparation method thereof and application thereof in photocatalysis. BACKGROUND

[0002] Under the background of "double carbon", hydrogen energy has become an important starting point to promote the green and low-carbon transformation of energy production and consumption, and is the main development direction of energy structure optimization. Photocatalytic overall water splitting is an ideal way to synthesize green hydrogen, but the current problem is that there are still few suitable photocatalysts that can efficiently convert solar energy into hydrogen energy, and its conversion efficiency is still far below the industrial application level. The main bottleneck is that the photocatalyst has low utilization rate of visible light, poor charge separation ability, and short lifetime of photo-generated carriers (electrons-holes).

[0003] Perylene imide photocatalysts have the advantages of low cost of raw materials, high controllability of structure, simple preparation and synthesis steps, wide spectral response, and high and stable photocatalytic water oxidation performance, and are a research hotspot in the field of photocatalytic water splitting in recent years. However, few people have successfully applied perylene imide to the field of overall water splitting, and due to the low long-range order of PDI organic polymers, they still face problems such as charge transfer and easy recombination of photo-generated carriers in practical application, resulting in low catalytic efficiency. The present application makes the following work on perylene imide photocatalytic overall water splitting. SUMMARY

[0004] In order to improve the above technical problems, the present application realizes the following technical scheme:

[0005] The present application provides a covalent organic framework (COF) material formed from electron donor unit monomers A and electron acceptor monomers B.

[0006] According to an embodiment of the present application, the monomers A are selected from the compounds of the following formula (1):

[0007]

[0008] wherein each R is the same or different, independently of one another, selected from H, halogen, C 1-20 alkyl, for example C 1-6 alkyl or C 10-18 alkyl, for example C 11 alkyl, C 12 alkyl, C 13 alkyl, C 14 alkyl, C 15 alkyl, C 16 alkyl, C 17 alkyl, C 18 alkyl.

[0009] According to embodiments of the present application, each R is the same or different, independently selected from ethyl, propyl, tridecyl, for example ethyl, isopropyl,

[0010] According to embodiments of the present application, the monomer A is selected from N,N'-di(ethane)-2,5,8,11-tetra(4-formylphenyl)perylene-3,4,9,10- bis(dicarboximide), N,N'-di(propane)-2,5,8,11-tetra(4-formylphenyl)perylene-3,4,9,10- bis(dicarboximide), N,N'-di(tridecane)-2,5,8,11-tetra(4-formylphenyl)perylene-3,4,9,10- bis(dicarboximide), and the like.

[0011] Preferably, N,N'-di(tridecane)-2,5,8,11-tetra(4-formylphenyl)perylene-3,4,9,10- bis(dicarboximide) has the following structure shown in formula (1),

[0012]

[0013] According to embodiments of the present application, the monomer B is selected from wherein L is a single bond or selected from each X is the same or different, independently selected from S(O)2, C(O); each Y is the same or different, independently selected from CH, N; each R1 is the same or different, independently selected from NH2, each R2 is the same or different, independently selected from H, OH, C 1-6 alkyl, C 1-6 alkoxy.

[0014] According to embodiments of the present application, the monomer B is selected from

[0015]

[0016] According to embodiments of the present application, the monomer B is selected from 3,7- diamino-dibenzo[b,d]thiophene sulfone, 2,7-diamino-9H-fluoren-9-one, 3,7-diamino-2,8- dimethyl-dibenzo[b,d]thiophene sulfone, 4,4-(benzo[l,2,5]thiadiazole-4,7-diyl)dianiline, and the like.

[0017] Preferably, 3,7-diamino-dibenzo[b,d]thiophene sulfone has the following structure shown in formula (2),

[0018]

[0019] According to an embodiment of the present application, the molar ratio of monomer A to monomer B in the covalent organic framework material is 1:0.5-1:5, for example 1:1-1:3, such as 1:1.5, 1:2, 1:3.

[0020] The present application also provides a method for preparing the covalent organic framework material, comprising the following steps: reacting monomer A and monomer B to obtain the organic framework material.

[0021] According to an embodiment of the present application, the reaction can be carried out in the presence of a solvent selected from an organic solvent; the organic solvent is selected from at least one of o-dichlorobenzene, n-butanol, ethanol, N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, dioxane and mesitylene.

[0022] According to an embodiment of the present application, the solvent can be a mixed solvent of mesitylene / dioxane or a mixed solvent of o-dichlorobenzene / n-butanol; the volume ratio of the two solvents in the mixed solvent is preferably 1:1.

[0023] According to an embodiment of the present application, the reaction can be carried out in the presence of a catalyst selected from at least one of acetic acid, p-toluenesulfonic acid and scandium triflate.

[0024] According to an embodiment of the present application, the concentration of the acetic acid is 3M-12M, for example 6M-10M, such as 6M, 9M, 12M.

[0025] According to an embodiment of the present application, the molar ratio of monomer A to catalyst is selected from 1:0.1-1:100, for example when the catalyst is acetic acid, the molar ratio is selected from 1:20-1:80, such as 1:40, 1:60, 1:80; when the catalyst is not acetic acid, the molar ratio is selected from 1:0.1-1:1, such as 1:0.1, 1:0.2, 1:0.3, 1:0.4, 1:0.5, 1:0.8.

[0026] According to an embodiment of the present application, the preparation method is a solvothermal method.

[0027] According to an embodiment of the present application, the conditions of the solvothermal method include: the reaction temperature is 120-180℃, such as 120℃, 150℃, 120℃, 180℃; the reaction time is 12-72h, such as 12h, 24h and 72h. Within the above-mentioned reaction temperature range and the above-mentioned reaction time, the crystallization of the covalent organic framework material can be promoted.

[0028] The present application also provides the use of the covalent organic framework as a photocatalyst, for example in the photocatalytic decomposition of water to generate H2 and O2.

[0029] Advantages of the present application

[0030] (1) The covalent organic framework (COF) material described in the present application can effectively inhibit the recombination of photo-generated electrons and holes, effectively improve the separation efficiency of photo-generated electrons and holes, promote the transfer of photo-generated charges, and realize efficient photocatalytic decomposition of water by combining electron donor PDI units with electron acceptor units to form COF as a photocatalyst;

[0031] (2) The preparation method of the material is simple, the raw materials are cheap and easy to obtain, the method is green and simple, and the material has the premise of being put into large-scale production in the future, and has good application prospect in solving future energy shortage and other problems;

[0032] (3) The photocatalyst is applied to catalyze overall water splitting, and the highest release rates of H2 and O2 are 0.517 mmol g -1 h -1 and 0.255 mmol g -1 h -1 respectively, and has superior potential in commercial application of photocatalytic water splitting for hydrogen production. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 is a structural schematic diagram of PDI-COF-1 prepared in the present application.

[0034] Figure 2 is an X-ray powder diffraction pattern of PDI-COF-1 prepared in Example 5 of the present application.

[0035] Figure 3 is a BET graph of PDI-COF-1 prepared in Example 5 of the present application.

[0036] Figure 4 is a performance comparison diagram of PDI-COF-1-4 prepared in Examples 5, 7, 8 and 9 of the present application for photocatalytic overall water splitting.

[0037] TERMS DEFINITION AND EXPLANATION

[0038] Unless otherwise specified, the definitions of groups and terms in the present application specification and claims, including the definitions of examples, exemplary definitions, preferred definitions, definitions in tables, definitions of specific compounds in examples, etc., can be combined and combined with each other. The group definition and compound structure after such combination should be understood as within the scope recorded in the present application specification and / or claims.

[0039] Unless otherwise indicated, the numerical values in the description and the claims are to be understood to be approximate, and thus the numerical values encompass the numerical values within the range expressed by the number. For example, the numerical range "1-20" is intended to convey the range of values from 1 to 10, i.e., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, as well as the range of values from 11 to 20, i.e., 11, 12, 13, 14, 15, 16, 17, 18, 19, 20.

[0040] The term "halogen" means fluorine, chlorine, bromine and iodine.

[0041] The term "C 1-20 "alkyl" is to be understood as meaning a straight-chain or branched saturated monovalent hydrocarbon group having from 1 to 20 carbon atoms. For example, "C 1-6 "alkyl" means a straight-chain and branched alkyl group having 1, 2, 3, 4, 5 or 6 carbon atoms, "C 10-18 "alkyl" means a straight-chain and branched alkyl group having 10, 11, 12, 13, 14, 15, 16, 17 or 18 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl and the like or isomers thereof, and also undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl and isomers thereof.

[0042] The term "C 1-6 "alkoxy" means the term "C 1-6 alkyl-O-", wherein "C 1-6 alkyl" is as defined above. DETAILED DESCRIPTION

[0043] The technical solutions of the present application will be further described in detail below in combination with specific examples. It should be understood that the following examples are only illustratively and explain the present application, and should not be interpreted as limiting the scope of protection of the present application. Any technology realized on the basis of the above description of the present application is encompassed within the scope intended to be protected by the present application.

[0044] The starting materials and reagents used in the following examples are commercially available or can be prepared by known methods unless otherwise stated. N,N'-Di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) was prepared according to the reference J. Am. Chem. Soc. 2020, 142, 8, 3712-3717.

[0045] Example 1

[0046] The preparation method of PDI-COF-1 is as follows:

[0047] 3,7-Diamino-dibenzothiophene sulfone 24.6 mg (0.1 mmol) and N,N'-Di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 2 mL of o-dichlorobenzene and 2 mL of n-butanol were added, and ultrasonic dispersion was performed for 10 min. 0.5 mL of 6M aqueous acetic acid solution was added, and after 3 cycles of liquid nitrogen freezing pump circulation to remove water and oxygen, it was sealed under vacuum, and heated at 120°C for 3d to prepare PDI-COF-1.

[0048] Example 2

[0049] The preparation method of PDI-COF-1 is as follows:

[0050] 3,7-Diamino-dibenzothiophene sulfone 24.6 mg (0.1 mmol) and N,N'-Di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 2 mL of o-dichlorobenzene and 2 mL of n-butanol were added, and ultrasonic dispersion was performed for 10 min. 0.5 mL of 6M aqueous acetic acid solution was added, and after 3 cycles of liquid nitrogen freezing pump circulation to remove water and oxygen, it was sealed under vacuum, and heated at 150°C for 3d to prepare PDI-COF-1.

[0051] Example 3

[0052] The preparation method of PDI-COF-1 is as follows:

[0053] PDI-COF-1 was prepared as follows: 3,7-diamino-dibenzo[b,d]thiophene sulfone 24.6 mg (0.1 mmol) and N,N'-di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 2 mL of o-dichlorobenzene and 2 mL of n-butanol were added, and ultrasonic dispersion was performed for 10 min. 0.5 mL of 6M aqueous acetic acid solution was added, and after three cycles of water and oxygen removal by liquid nitrogen freezing pump circulation, it was sealed under vacuum and heated at 180°C for 3d to obtain PDI-COF-1.

[0054] Example 4

[0055] PDI-COF-1 was prepared as follows:

[0056] PDI-COF-1 was prepared as follows: 3,7-diamino-dibenzo[b,d]thiophene sulfone 24.6 mg (0.1 mmol) and N,N'-di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 2 mL of o-dichlorobenzene and 2 mL of n-butanol were added, and ultrasonic dispersion was performed for 10 min. 0.5 mL of 6M aqueous acetic acid solution was added, and after three cycles of water and oxygen removal by liquid nitrogen freezing pump circulation, it was sealed under vacuum and heated at 150°C for 3d to obtain PDI-COF-1.

[0057] Example 5

[0058] PDI-COF-1 was prepared as follows:

[0059] PDI-COF-1 was prepared as follows: 3,7-diamino-dibenzo[b,d]thiophene sulfone 24.6 mg (0.1 mmol) and N,N'-di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 5 mM p-toluenesulfonic acid in 4 mL of o-dichlorobenzene / n-butanol (1:1) mixed solution was added, and ultrasonic dispersion was performed for 10 min. After three cycles of water and oxygen removal by liquid nitrogen freezing pump circulation, it was sealed under vacuum and heated at 150°C for 3d to obtain PDI-COF-1.

[0060] Example 6

[0061] PDI-COF-1 was prepared as follows:

[0062] PDI-COF-1 was prepared by the following method: 3,7-diamino-dibenzo[b,d]thiophene sulfone 24.6 mg (0.1 mmol) and N,N'-di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 5 mM scandium triflate in 4 mL of o-dichlorobenzene / n-butanol (1:1) mixed solution was added, and ultrasonic dispersion was performed for 10 min. After three cycles of water and oxygen removal by liquid nitrogen under the freeze pump, it was sealed under vacuum and heated at 150 °C for 3 d to obtain PDI-COF-1.

[0063] Example 7

[0064] PDI-COF-2 was prepared by the following method:

[0065] PDI-COF-2 was prepared by the following method: 3,7-diamino-dibenzo[b,d]thiophene sulfone 24.6 mg (0.1 mmol) and N,N'-di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 5 mM scandium triflate in 4 mL of o-dichlorobenzene / n-butanol (1:1) mixed solution was added, and ultrasonic dispersion was performed for 10 min. After three cycles of water and oxygen removal by liquid nitrogen under the freeze pump, it was sealed under vacuum and heated at 150 °C for 3 d to obtain PDI-COF-2.

[0066] Example 8

[0067] PDI-COF-3 was prepared by the following method:

[0068] PDI-COF-3 was prepared by the following method: 3,7-diamino-dibenzo[b,d]thiophene sulfone 24.6 mg (0.1 mmol) and N,N'-di(tridecyl)-2,5,8,11-tetrakis(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 5 mM scandium triflate in 4 mL of o-dichlorobenzene / n-butanol (1:1) mixed solution was added, and ultrasonic dispersion was performed for 10 min. After three cycles of water and oxygen removal by liquid nitrogen under the freeze pump, it was sealed under vacuum and heated at 150 °C for 3 d to obtain PDI-COF-3.

[0069] Example 9

[0070] PDI-COF-4 was prepared by the following method:

[0071] 3,9-diamino-benzobis[l]benzothiophene-5,5,11,11-tetraoxide 32 mg (0.1 mmol) and N,N'-di(tridecyl)-2,5,8,11-tetra(4-formylphenyl)perylene-3,4,9,10-bis(dicarboximide) 44.5 mg (0.05 mmol) were placed in a 10 mL heat-resistant tube, 5 mM scandium triflate in 4 mL of o-dichlorobenzene / n-butanol (1:1) mixed solution was added, ultrasonic dispersion for 10 min, after 3 times of liquid nitrogen under the freeze pump circulation to remove water and oxygen, vacuum sealing, heating at 150 °C for 3 d, PDI-COF-4 was prepared.

[0072] Test Example 1

[0073] 15 mg of PDI-COF powder prepared in Examples 5, 7, 8, and 9 was respectively ultrasonically dispersed in 100 mL of ionized water, a 300 W xenon lamp was used to irradiate the reaction container at the top, and the Perfect Light (Labsolar 6A) device was used to carry out the overall water splitting photocatalytic reaction, the generated gas was detected by the Perfect Light (Labsolar 6A) device into the GC9790 gas chromatograph, and the results are shown in Table 1. Figure 4 .

[0074] The above has exemplarily described the embodiments of the technical scheme of the present disclosure. It should be understood that the protection scope of the present disclosure is not limited to the above embodiments. Any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present disclosure shall be included in the protection scope of the claims of the present application.

Claims

1. A covalent organic framework (COF) material formed from an electron donor monomer A and an electron acceptor monomer B; The monomer A is selected from the compounds shown in formula (1): in, Each R may be the same or different, and is independently selected from H, halogen, C. 1-20 Alkyl, such as C 1-6 Alkyl or C 10-18 Alkyl groups, such as C 11 Alkyl, C 12 Alkyl, C 13 Alkyl, C 14 Alkyl, C 15 Alkyl, C 16 Alkyl, C 17 Alkyl, C 18 alkyl; The monomer B is selected from Where L is a single bond or selected from Each X is the same or different, and is independently selected from S(O)2 and C(O); each Y is the same or different, and is independently selected from CH and N; each R1 is the same or different, and is independently selected from NH2. Each R2 may be the same or different, and is independently selected from H, OH, and C. 1-6 Alkyl, C 1-6 Alkyl group.

2. The covalent organic framework material according to claim 1, characterized in that, Each R may be the same or different, and is independently selected from ethyl, propyl, and tridecyl, such as ethyl, isopropyl, ...

3. The covalent organic framework material according to claim 1 or 2, characterized in that, The monomer A is selected from N,N'-di(ethane)-2,5,8,11-tetra(4-formylphenyl)perylene-3,4,9,10-di(dicarboximide), N,N'-di(propyl)-2,5,8,11-tetra(4-formylphenyl)perylene-3,4,9,10-di(dicarboximide), and N,N'-di(tetrazyl)-2,5,8,11-tetra(4-formylphenyl)perylene-3,4,9,10-di(dicarboximide); Preferably, the monomer A has the structure shown in formula (1).

4. The covalent organic framework material according to any one of claims 1-3, characterized in that, The monomer B is selected from Preferably, the monomer B is selected from 3,7-diamino-dibenzothiophene sulfone, 2,7-diamino-9H-fluorene-9-one, 3,7-diamino-2,8-dimethyl-dibenzothiophene sulfone, and 4,4-(benzo[1,2,5]thiadiazole-4,7-diyl)diphenylamine; Preferably, the monomer B has the structure shown in formula (2).

5. The covalent organic framework material according to any one of claims 1-4, characterized in that, In the covalent organic framework material, the molar ratio of monomer A to monomer B is 1:0.5 to 1:5, for example 1:1 to 1:3, for example 1:1.5, 1:2, or 1:

3.

6. A method for preparing the covalent organic framework material according to any one of claims 1-5, comprising the following steps: Monomer A and monomer B react to obtain the organic framework material.

7. The preparation method according to claim 6, characterized in that, The reaction can be carried out in the presence of a solvent selected from organic solvents; the organic solvent is selected from at least one of o-dichlorobenzene, n-butanol, ethanol, N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, dioxane, and mesitylene. Preferably, the solvent can be a mixed solvent of mesitylene / dioxane or a mixed solvent of o-dichlorobenzene / n-butanol; the volume ratio of the two solvents in the mixed solvent is preferably 1:

1.

8. The preparation method according to claim 6 or 7, characterized in that, The reaction can be carried out in the presence of a catalyst selected from at least one of acetic acid, p-toluenesulfonic acid, and scandium trifluoromethanesulfonate. Preferably, the concentration of the acetic acid is 3M-12M, for example 6M-10M, such as 6M, 9M, and 12M. Preferably, the molar ratio of monomer A to catalyst is selected from 1:0.1 to 1:

100. For example, when the catalyst is acetic acid, the molar ratio is selected from 1:20 to 1:80, such as 1:40, 1:60, 1:80; when the catalyst is not acetic acid, the molar ratio is selected from 1:0.1 to 1:

1.

9. The preparation method according to any one of claims 6-8, characterized in that, The preparation method is a solvothermal method; Preferably, the reaction temperature of the solvothermal method is 120–180°C, and the reaction time is 12–72 h.

10. The application of the covalent organic framework according to any one of claims 1-5 as a photocatalyst, for example, in the photocatalytic splitting of water to produce H2 and O2.

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