阅读说明：本技术 硫醚功能化的芘基共价有机框架材料及其制备方法和应用 (Thioether-functionalized pyrenyl covalent organic framework material and preparation method and application thereof ) 是由 申燕 周志明 于 2020-12-18 设计创作，主要内容包括：本发明属于共价有机框架材料领域,具体涉及硫醚功能化的芘基共价有机框架材料及其制备方法和应用。本发明将2,5-双(2-(乙硫基)乙氧基)对苯二甲酰肼和1,3,6,8-四-(对醛基苯基)-芘加入到溶剂体系中,反应制得硫醚功能化的芘基共价有机框架材料。本发明合成方法所用到的设备和化学试剂易于获取,工艺操作简便,适用性强,工业应用价值高,合成产率相对较高,本发明制备的芘基共价有机框架材料对可见光具有良好的响应,在光催化分解水制氢领域有良好的潜在应用价值,易于推广利用。(The invention belongs to the field of covalent organic framework materials, and particularly relates to a thioether functionalized pyrenyl covalent organic framework material, and a preparation method and application thereof. According to the preparation method, 2, 5-bis (2- (ethylthio) ethoxy) terephthaloyl hydrazine and 1,3,6, 8-tetra- (p-aldehyde phenyl) -pyrene are added into a solvent system and react to prepare the thioether functionalized pyrenyl covalent organic framework material. The equipment and chemical reagents used in the synthesis method are easy to obtain, the process operation is simple and convenient, the applicability is strong, the industrial application value is high, the synthesis yield is relatively high, the pyrenyl covalent organic framework material prepared by the method has good response to visible light, has good potential application value in the field of hydrogen production by photocatalytic water decomposition, and is easy to popularize and utilize.)

1. A thioether-functionalized pyrenyl covalent organic framework material is characterized in that the structural formula is shown as formula (1):

wherein, in the formula (1), the benzene rings are connectedShowing the omitted repeating structural elements.

2. The preparation method of the thioether-functionalized pyrenyl covalent organic framework material is characterized in that 2, 5-bis (2- (ethylthio) ethoxy) terephthaloyl hydrazine and 1,3,6, 8-tetra- (p-aldehydic phenyl) -pyrene are added into a solvent system and react to prepare the pyrenyl covalent organic framework material in the claim 1.

3. The preparation method according to claim 2, characterized by comprising the following steps:

(1) adding 2, 5-bis (2- (ethylthio) ethoxy) terephthaloyl hydrazine and 1,3,6, 8-tetra- (p-aldehyde phenyl) -pyrene into a solvent system, and uniformly mixing by ultrasonic;

(2) vacuumizing the reaction system and sealing;

(3) heating to react to generate yellow solid precipitate, wherein the reaction temperature is 100-120 ℃, and the reaction time is 3-5 days;

(4) and filtering and separating to obtain a precipitate, washing and drying to obtain the thioether-functionalized pyrenyl covalent organic framework material.

4. The method according to claim 2 or 3, wherein the solvent is a mixture of o-dichlorobenzene, absolute ethyl alcohol and acetic acid.

5. The method according to claim 4, wherein the volume ratio of the o-dichlorobenzene, the absolute ethanol and the acetic acid is (5-10): (1-2).

6. The preparation method according to claim 2, wherein the vacuum is applied in the step (2), the reaction system is frozen by a liquid nitrogen bath, then thawed, and flame sealing is performed after the vacuum application is finished.

7. The method according to claim 3, wherein the washing comprises a first washing and a second washing, the first washing comprises washing with anhydrous tetrahydrofuran and anhydrous ethanol for several times, and the second washing comprises washing with dichloromethane and N, N-dimethylformamide for several times.

8. The method according to claim 3, wherein the drying is carried out at 80-100 ℃ for 12-24 hours under vacuum.

9. The use of the thioether-functionalized pyrenyl covalent organic framework material of claim 1, wherein said use comprises as a catalyst for photocatalytic decomposition of water to produce hydrogen.

10. The use of the thioether-functionalized pyrenyl covalent organic framework material according to claim 9, wherein the sacrificial donor used is triethanolamine and the co-catalyst is Au nanoparticles.

Technical Field

The invention belongs to the field of covalent organic framework materials, and particularly relates to a thioether-functionalized pyrenyl covalent organic framework material as well as a preparation method and application thereof.

Background

Covalent organic framework materials (COFs) are a new class of crystalline organic porous materials formed by dynamic covalent bonding. Compared with the traditional porous carbon material or MOFs material, the material has the advantages of low density and high stability. With the rapid increase in global energy demand, the search for clean and renewable energy sources as alternatives to the consumption of fossil fuels has become more urgent than ever. Due to its high energy density and carbon-free emission, hydrogen energy is considered one of the most promising energy sources to address the global energy crisis. Photocatalytic water splitting is an extremely important technical progress, rich solar energy can be utilized to directly realize proton reduction, and clean hydrogen energy is obtained, which is helpful for relieving and even solving the current environmental problem and energy problem. Therefore, the photocatalytic hydrogen production technology developed based on hydrogen energy is gradually paid attention and paid attention by researchers. Most of traditional catalytic hydrogen production materials are concentrated on inorganic semiconductor materials, and microporous materials composed of some light elements are rarely reported.

CN110229345A discloses a covalent organic framework material containing a beta keto enamine structure, a preparation method and an application thereof, and specifically discloses a covalent organic framework material containing a beta keto enamine structure, which is obtained by uniformly mixing pyrenyl diphenylamine and 2,4, 6-trimethyloyltrimesic phenol in an organic solvent, adding a weakly acidic catalyst, and carrying out reversible Schiff base reaction and irreversible enol-keto tautomerism reaction under the solvothermal condition. The covalent organic framework material of the technical scheme mainly aims to meet the actual requirements of an electrochemical energy storage device, has high specific capacitance and high cycle stability, but is difficult to be used for photocatalytic hydrogen production.

CN111607051A discloses a three-dimensional fluorescent covalent organic framework material, a preparation method and an application thereof, wherein hexamethyl biphenyl aldehyde derivatives and a series of pyrenyl amine derivatives are used as raw materials, o-dichlorobenzene and mesitylene are used as solvents, acetic acid is used as a catalyst, and the solvents are subjected to a thermal reaction for a plurality of days. After the reaction is finished, DMF and THF are sequentially used for suction filtration and washing, and the yellow powder is obtained after the Soxhlet extraction for 24 hours and vacuum drying. The covalent organic framework material of the technical scheme mainly takes hexamethyl biphenyl tetra-aldehyde based on steric effect and pyrenyl tetra-amine with fluorescence as construction monomers, and the synthesized 'Turn-on' type three-dimensional fluorescent covalent organic framework has rich cavity structures and conjugated three-dimensional frameworks, shows good application prospects in the field of fluorescence sensing, but is difficult to be used for photocatalytic hydrogen production.

In view of the foregoing, the prior art is still lacking a covalent organic framework material that is satisfactory for photocatalytic hydrogen production applications.

Disclosure of Invention

Aiming at the improvement requirement of the prior art, the invention provides a thioether functionalized pyrenyl covalent organic framework material, which has better visible light response, proper energy band position and better photocatalytic hydrogen production activity, can improve the photocatalytic hydrogen production activity by metal doping and other methods, and can be applied to photocatalytic hydrogen production.

To achieve the above object, according to one aspect of the present invention, there is provided a thioether-functionalized pyrenyl covalent organic framework material, having a structural formula shown in formula (1):

wherein "… …" attached to the benzene ring in the formula (1) represents an omitted repeating structural unit.

According to another aspect of the invention, a preparation method of the thioether-functionalized pyrenyl covalent organic framework material is provided, and the pyrenyl covalent organic framework material is prepared by adding 2, 5-bis (2- (ethylthio) ethoxy) terephthaloyl hydrazine and 1,3,6, 8-tetra- (p-aldehydiphenyl) -pyrene into a solvent system and reacting.

Preferably, the method specifically comprises the following steps:

(1) adding 2, 5-bis (2- (ethylthio) ethoxy) terephthaloyl hydrazine and 1,3,6, 8-tetra- (p-aldehyde phenyl) -pyrene into a solvent system, and uniformly mixing by ultrasonic;

(2) vacuumizing the reaction system and sealing;

(3) heating to react to generate yellow solid precipitate, wherein the reaction temperature is 100-120 ℃, and the reaction time is 3-5 days;

(4) and filtering and separating to obtain a precipitate, washing and drying to obtain the thioether-functionalized pyrenyl covalent organic framework material.

Preferably, the solvent is a mixture of o-dichlorobenzene, absolute ethyl alcohol and acetic acid.

Preferably, the volume ratio of the o-dichlorobenzene, the absolute ethyl alcohol and the acetic acid is (5-10): (1-2).

Preferably, when the vacuum is drawn in the step (2), the reaction system is frozen by a liquid nitrogen bath, then thawed, and flame sealing is performed after the vacuum drawing is finished.

Preferably, the washing comprises a first washing and a second washing, wherein the first washing is washing by anhydrous tetrahydrofuran and anhydrous ethanol for several times, and the second washing is washing by dichloromethane and N, N-dimethylformamide for several times.

Preferably, the drying is vacuum drying at 80-100 ℃ for 12-24 h.

According to another aspect of the present invention, there is provided the use of thioether-functionalized pyrenyl covalent organic framework materials, including as catalysts for the photocatalytic decomposition of water to produce hydrogen.

Preferably, the sacrificial donor is triethanolamine, the promoter is Au nanoparticles, and the precursor of the promoter is chloroauric acid.

The invention has the following beneficial effects:

(1) according to the invention, 2, 5-bis (2- (ethylthio) ethoxy) terephthaloyl hydrazine and 1,3,6, 8-tetra- (p-aldehyde phenyl) -pyrene are used as reaction raw materials, and the thioether functionalized pyrenyl covalent organic framework material is synthesized by solvothermal reaction in an o-dichlorobenzene, absolute ethyl alcohol and acetic acid solvent system, and has good visible light response, a proper energy band position, relatively high synthesis yield, good response to visible light and good potential application value in the field of hydrogen production by photocatalytic water decomposition.

(2) The equipment and chemical reagents used in the synthesis method are easy to obtain, the process operation is simple and convenient, the applicability is strong, the industrial application value is high, and the method is easy to popularize and utilize.

Drawings

FIG. 1 shows S obtained in example 1₄-a schematic synthesis of COF;

FIG. 2 shows S obtained in example 1₄-X-ray powder diffractogram of COF;

FIG. 3 shows S obtained in example 1₄-fourier transform infrared spectrogram of COF and of synthetic monomers;

FIG. 4 shows S obtained in example 1₄-solid uv absorption spectrum of COF;

FIG. 5 shows S obtained in example 1₄-COF photocatalytic cycle hydrogen production test pattern under pure water condition.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

Examples

The embodiment of the invention provides a thioether-functionalized pyrenyl covalent organic framework material, which has a structural formula shown in a formula (1):

wherein "… …" attached to the benzene ring in the formula (1) represents an omitted repeating structural unit.

In the preparation method of the thioether-functionalized pyrenyl covalent organic framework material in the embodiment of the invention, 2, 5-bis (2- (ethylthio) ethoxy) terephthaloyl hydrazine and 1,3,6, 8-tetra- (p-aldehyde phenyl) -pyrene are added into a solvent system and react to prepare the pyrenyl covalent organic framework material. The following are specific examples.

Example 1

A thioether-functionalized pyrenyl covalent organic framework material is prepared by the following steps:

(1) 2, 5-bis (2- (ethylthio) ethoxy) terephthaloyl hydrazine (19.52mg, 48.5. mu. mol) and 1,3,6, 8-tetra- (p-formylphenyl) -pyrene (15mg, 24.25. mu. mol) were added to a solvent system of 1.1mL o-dichlorobenzene, anhydrous ethanol and acetic acid at a volume ratio of 5: 5: 1, placing the mixture in a 5mL Pyrex tube, wherein the length of the Pyrex tube body is 20cm, the length of the neck is 1cm, carrying out ultrasonic treatment for 3 minutes, and uniformly mixing.

(2) The Pyrex tubes were frozen in a liquid nitrogen bath, thawed, evacuated to an internal pressure of 0mbar and flame sealed.

(3) The Pyrex tube was placed in an oven at 120 ℃ for 3 days to yield a yellow solid.

(4) The precipitate was collected by suction filtration, washed three times with anhydrous tetrahydrofuran and anhydrous ethanol, and then washed three times with dichloromethane and N, N-dimethylformamide. Vacuum drying the yellow powder at 80 ℃ for 24h to obtain a thioether-functionalized pyrenyl covalent organic framework material marked as S₄-COF, weighing 33.5mg, calculating an isolated yield of 69%.

Thioether-functionalized pyrenyl covalent organic framework material S prepared in this example₄The scheme for the synthesis of-COF is shown in FIG. 1.

Test examples

X-ray powder diffraction test, S of example 1₄COF was tested and the results are shown in figure 2. S₄The X-ray powder diffraction pattern of-COF shows peak shapes at 3.2 °, 4.2 °, 6.5 °, 9.8 ° and 24.5 °, which correspond to the (110), (200), (220), (330) and (001) crystal planes, respectively. Among the various possible stacking modes, the AA stacking mode is the most structurally stable stacking form in energy. The experimentally observed X-ray powder diffraction curve matches the structurally fitted AA packing pattern.

2. Fourier transform Infrared Spectroscopy test S of example 1₄COF was tested and the results are shown in figure 3. S₄Fourier transform of-COF and of synthetic monomersThe infrared spectroscopy is used to verify the stretching vibration of each functional group. S compared with hydrazide monomer and pyrenyl monomer₄Fourier transform infrared spectroscopy of-COF revealed a stretched band (1697 cm) of-CHO in 1,3,6, 8-tetra- (p-formylphenyl) -pyrene^-1) Disappeared and is 1662cm^-1Stretching vibration of the C ═ O bond occurs. Further, a characteristic stretching vibration mode related to the C ═ N bond appears at 1601cm^-1And 1226-1203 cm^-1This indicates the successful formation of the imine function.

3. Solid UV absorption Spectroscopy test S of example 1₄COF was tested and the results are shown in fig. 4. The ultraviolet absorption spectrum of the solid shows that S₄The COF has a wide visible light absorption range and shows strong visible light collection capability.

Application examples

S prepared in example 1₄Application of-COF to photocatalytic recycling hydrogen production is described in detail below.

20mg of S prepared in example 1 are added₄-COF is taken as a photocatalyst and suspended in ultrapure water (50mL) containing triethanolamine (10 vol%) as a sacrificial electron donor, 1.0 wt% of Au (prepared by adopting chloroauric acid as a precursor) is dripped as a cocatalyst and dispersed in an ultrasonic bath for 5 minutes, and hydrogen is prepared by photocatalytic decomposition of pure water under the irradiation of visible light (more than or equal to 420nm), and a circulation experiment is carried out for 4 times, and each circulation is carried out for 4 hours. Analysis of the precipitated H by GC gas chromatography₂Amount of the compound (A).

S₄The photocatalytic cycle hydrogen production test pattern of-COF under pure water condition is shown in FIG. 5. As shown in FIG. 5, S₄The total amount of hydrogen production by photocatalytic water decomposition of-COF is 110.2 mu mol in the first operation for 4 hours, and the hydrogen production yield can still reach more than 80 mu mol after a stable test of a circulation experiment is carried out under visible light irradiation (lambda is more than or equal to 420nm) for 16 hours.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.