阅读说明：本技术 苯并噻唑类共价有机框架材料、其制备方法及应用 (Benzothiazole covalent organic framework material, preparation method and application thereof ) 是由 宁静 周生祥 郝龙 于 2021-09-18 设计创作，主要内容包括：本发明公开了苯并噻唑类共价有机框架材料、其制备方法及应用,属于材料制备技术领域。本发明所述的苯并噻唑类共价有机框架材料,是由6,6’-联苯并噻唑-2,2’-二胺和2,4,6-三羟基苯-1,3,5-三甲醛作为反应底物制备而成。苯并噻唑类共价有机框架材料具有高比表面积,对CO-(2)有较好的选择性吸收效果,因此能够在CO-(2)吸附领域中具有较好的应用；同时,苯并噻唑类共价有机框架材料能够对电容器中的离子进行吸附存储,因此还能够在超级电容器的制备等领域具有较好的应用。(The invention discloses a benzothiazole covalent organic framework material, a preparation method and application thereof, belonging to the technical field of material preparation. The benzothiazole covalent organic framework material is prepared from 6, 6' -biphenyl thiazole-2, 2-Diamine and 2,4, 6-trihydroxybenzene-1, 3, 5-trimethyl aldehyde are used as reaction substrates. The benzothiazole covalent organic framework material has high specific surface area and is used for CO 2 Has better selective absorption effect, thereby being capable of absorbing CO 2 The method has good application in the adsorption field; meanwhile, the benzothiazole covalent organic framework material can adsorb and store ions in the capacitor, so that the benzothiazole covalent organic framework material can be well applied to the fields of preparation of super capacitors and the like.)

1. A benzothiazole covalent organic framework material, which is characterized by comprising a structural unit shown as the following formula I;

2. use of benzothiazole covalent organic framework material of claim 1 in preparation of CO₂Use in a material for adsorbing and/or assembling a supercapacitor.

3. A process for preparing a benzothiazole covalent organic framework material of claim 1, characterized by the following steps:

placing 6,6 '-biphenyl thiazole-2, 2' -diamine and 2,4, 6-trihydroxybenzene-1, 3, 5-trimethyl aldehyde in a mixed solvent, adding acetic acid as a catalyst, ultrasonically mixing, then removing oxygen in a reaction system, vacuumizing, sealing the reaction system, reacting at 90-150 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain reaction precipitate, cleaning and drying the precipitate to obtain the COF-SZ material.

4. The method according to claim 3, wherein the mixed solvent is a mixed solvent of o-dichlorobenzene and 1, 4-dioxane in a volume ratio of 1:4 to 3:1 or a mixed solvent of o-dichlorobenzene and mesitylene in a volume ratio of 4:1 to 1: 4.

5. A benzothiazole covalent organic framework carbonized material, which is characterized in that the benzothiazole covalent organic framework carbonized material is prepared by carbonizing the benzothiazole covalent organic framework carbonized material in claim 1.

6. A process for preparing a benzothiazole covalent organic framework carbonising material according to claim 5, characterized in that it comprises the following steps:

covalent organic framework materials of benzothiazoles with ZnCl₂Mixing the materials under the anhydrous and oxygen-free conditions, heating the reaction system at the speed of 3-10 ℃/min, maintaining the temperature at 550-700 ℃ for high-temperature treatment for 2-96 h, and cleaning and drying the reaction product after the reaction system is cooled to obtain the benzothiazole covalent organic framework carbonized material.

7. The method according to claim 6, wherein the benzothiazole covalent organic framework material is mixed with ZnCl₂The mass ratio of (A) to (B) is 1-2: 5.

8. Claim 5The benzothiazole covalent organic framework carbonized material is in CO₂Use in adsorption and/or assembly of supercapacitors.

9. A supercapacitor comprising the benzothiazole covalent organic framework carbonized material of claim 5.

10. The method for preparing the supercapacitor of claim 9, comprising the steps of:

mixing benzothiazole covalent organic framework carbonized materials, carbon black and polytetrafluoroethylene, grinding the mixture into a uniform film, drying the film, cutting the film into small wafers, taking two small wafers with similar mass as electrode plates, pressing the electrode plates on a stainless steel mesh current collector, separating the electrode plates by using glass fibers as a diaphragm, and then immersing the electrode plates into ionic liquid 1-ethyl-3-methylimidazole tetrafluoroborate electrolyte to form the super capacitor.

Technical Field

The invention belongs to the technical field of material preparation, and particularly relates to a benzothiazole covalent organic framework material, and a preparation method and application thereof.

Background

With the progress of human society and the development of scientific technology, the problem of greenhouse effect is becoming more and more serious and becoming a hot problem of scientific research. CO 2₂Is the main reason of causing greenhouse effect and is a precious carbon resource, so for the consideration of environmental protection and resource utilization, CO is used₂The capture of (b) is of great significance. Efficient CO₂The adsorbent material needs to have an appropriate pore structure and a high specific surface area, and also needs to have an appropriate surface chemical structure. Similarly, as an efficient energy storage device, the supercapacitor has similar performance requirements for its electrode material, and also needs a large ion storage space and transport channel, and appropriate surface properties to ensure good wetting of the electrolyte.

Covalent Organic Frameworks (COFs) are a crystalline, regular, porous material made up of small molecular monomers linked by specific Organic reactions. The abundant continuous pore channel structure has the characteristics of high specific surface area and low density, and diversified precursors and reaction types enable the continuous pore channel structure to have a chemical structure capable of being flexibly regulated, so that the COFs have good application potential in the fields of gas adsorption, super capacitors and the like.

Benzothiazole and derivatives thereof have good stability and unique chemical and biological properties, and at present, extensive research exists in the aspects of fluorescent probes, medicinal chemistry and the like. Benzothiazole is taken as a multi-heterocyclic structure, and if the benzothiazole can be combined with COFs materials, heteroatoms such as S, N and the like on a thiazole ring can play a role in regulating and controlling an electronic structure, so that the surface chemical state of the materials is improved. Therefore, a great research space exists for reasonable design and synthesis of novel COFs materials aiming at gas selective adsorption and ion adsorption storage in a capacitor.

Disclosure of Invention

The invention provides a benzothiazole covalent organic framework material (COF-SZ material), which is a novel covalent organic framework material and can show excellent performance on carbon dioxide adsorption and a super capacitor, in particular, the benzothiazole covalent organic framework material is a two-dimensional porous polymer with a structural unit shown as the following formula I:

the COF-SZ material has high specific surface area to CO₂Has better selective absorption effect, thereby being capable of absorbing CO₂The adsorption field shows better potential; meanwhile, the ion adsorption storage device can adsorb and store ions in the capacitor, and therefore, the ion adsorption storage device can also have a good application prospect in the fields of super capacitor preparation and the like. Besides, the COF-SZ material can be modified to derive other COF materials or be used as a template to synthesize other porous materials, and the like, and the application can almost cover various fields. Preferably, the COF-SZ material can be carbonized for CO₂Adsorption and/or preparation of super capacitor.

The invention provides a preparation method of the COF-SZ material, which comprises the following steps:

placing 6,6 '-biphenyl thiazole-2, 2' -diamine (CAS number: 53357-04-3) and 2,4, 6-trihydroxybenzene-1, 3, 5-trimethylaldehyde (CAS number: 34374-88-4) in a mixed solvent, adding acetic acid as a catalyst, ultrasonically mixing, removing oxygen in a reaction system, vacuumizing, sealing the reaction system, reacting at 90-150 ℃, cooling the reaction system after the reaction is finished, centrifuging to obtain a reaction precipitate, cleaning and drying the precipitate to obtain the COF-SZ material.

In the preparation method of the COF-SZ material, the molar ratio of the 6,6 '-biphenyl thiazole-2, 2' -diamine to the 2,4, 6-trihydroxybenzene-1, 3, 5-trimethyl aldehyde is 3: 2.

In the preparation method of the COF-SZ material, the concentration of acetic acid is 1-9 mol/L, preferably 3-6 mol/L.

In the preparation method of the COF-SZ material, the mixed solvent is selected from a mixed solvent of o-dichlorobenzene and 1, 4-dioxane in a volume ratio of 1: 4-3: 1 or a mixed solvent of o-dichlorobenzene and mesitylene in a volume ratio of 4: 1-1: 4. Preferably, the volume ratio of ortho-dichlorobenzene to 1, 4-dioxane is 1: 3. Preferably, the volume ratio of ortho-dichlorobenzene to mesitylene is 1: 3.

In the preparation method of the COF-SZ material, the oxygen in the reaction system is removed by adopting the degassing circular treatment of freezing, vacuumizing, filling nitrogen and unfreezing.

In the preparation method of the COF-SZ material, the reaction time is preferably 40-75 h at 90-150 ℃.

In the preparation method of the COF-SZ material, the centrifugal rate is 5000 r/min.

In the preparation method of the COF-SZ material, tetrahydrofuran is adopted for cleaning the precipitate, and the precipitate is dried in an oven at 120 ℃ for one day.

The invention also provides a benzothiazole covalent organic framework carbonized material (COF-SZ-carbonized material), which is prepared by the following method: the COF-SZ material is mixed with ZnCl₂And (2) mixing under anhydrous and oxygen-free conditions, heating the reaction system at a speed of 3-10 ℃/min, maintaining the temperature at 550-700 ℃ for high-temperature treatment for 2-96 h, and cleaning and drying a reaction product after the reaction system is cooled to obtain the COF-SZ-carbonized material.

In the preparation method of the COF-SZ-carbonized material, the COF-SZ material and ZnCl are adopted₂The mass ratio of (A) to (B) is 1-2: 5.

In the preparation method of the COF-SZ-carbonized material, diluted hydrochloric acid at 70-80 ℃, deionized water and tetrahydrofuran are sequentially adopted to clean a reaction product, and drying is to dry the cleaned reaction product in a 120 ℃ drying oven for one day.

The COF-SZ-carbonized material toolHas high specific surface area to CO₂Has better selective absorption effect, thereby being applicable to CO₂The field of adsorption; meanwhile, the ion adsorption storage device can adsorb and store ions in the capacitor, and therefore, the ion adsorption storage device can be well applied to the technical fields of preparation of super capacitors and the like.

The invention also provides a super capacitor which is assembled by the COF-SZ-carbonized material; specifically, the preparation method of the supercapacitor comprises the following steps:

the method comprises the steps of mixing COF-SZ-carbonized materials, carbon black and polytetrafluoroethylene, grinding the mixture into a uniform film, drying the film, cutting the film into small round sheets, taking the two small round sheets with similar mass as electrode sheets, pressing the electrode sheets on a stainless steel mesh current collector, separating the electrode sheets by using glass fibers as a diaphragm, and then immersing the electrode sheets into ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate electrolyte to form the supercapacitor.

In the preparation method of the supercapacitor, the mass fractions of the COF-SZ-carbonized material, the carbon black and the polytetrafluoroethylene are 85%, 10% and 5% respectively.

The foregoing merely provides some preferred embodiments and is not intended to limit the scope of the invention. Taking the molar ratio of 6,6 '-biphenylthiazole-2, 2' -diamine to 2,4, 6-trihydroxybenzene-1, 3, 5-trifiuorol as an example, a molar ratio of 3:2 between the two is merely a preferred embodiment, and it does not mean that the solution of the present invention can be put into practice only when the molar ratio of the two is 3: 2. It is understood that, unless otherwise specified, the molar ratio of the two may be within other reasonable ranges to promote proper reaction, at least to achieve practical objectives of the present invention. Those skilled in the art who have the appropriate expertise can make a thorough understanding of this information cue.

The invention has the beneficial effects that:

COF-SZ material and COF-SZ-carbonized material both have high specific surface area to CO₂Has better selective absorption effect. COF-SZ material and COF-SZ-carbonized material at 273K temperature to CO₂Has a far greater adsorption capacityGreater than N under the same conditions₂Can realize the adsorption of CO₂Selective absorption of (3). Meanwhile, the COF-SZ material and the COF-SZ-carbonized material have good stability, and the super capacitor assembled by the materials has high rate performance.

Drawings

FIG. 1 is an X-ray diffraction spectrum of experiment, fitting and refinement of COF-SZ material;

FIG. 2 is an X-ray diffraction pattern of COF-SZ-carbonized material;

FIG. 3 shows N of COF-SZ material and COF-SZ-carbonized material₂Adsorption and desorption curve graphs;

FIG. 4 shows N of COF-SZ material and COF-SZ-carbonized material₂And CO₂Adsorption curve diagram;

FIG. 5 is a graph showing the distribution of pore diameters of COF-SZ material and COF-SZ-carbonized material;

FIG. 6 is a cyclic voltammogram of a COF-SZ-carbonized material;

FIG. 7 is a small current constant current charge and discharge curve diagram of COF-SZ-carbonized material;

FIG. 8 is a graph of the large current constant current charge and discharge of COF-SZ-carbonized material;

FIG. 9 is a graph of specific capacity of COF-SZ-carbonized materials at different current densities;

FIG. 10 is a graph of energy density versus power density for COF-SZ-carbonized materials;

FIG. 11 is a contrast diagram of X-ray diffraction of COF-SZ materials prepared under different solvent ratios.

Detailed Description

Terms used in the present invention have generally meanings as commonly understood by one of ordinary skill in the art, unless otherwise specified. The present invention will be described in further detail with reference to the following data in conjunction with specific examples. The following examples are intended to illustrate the invention and are not intended to limit the scope of the invention in any way.

Example 1

The preparation of COF-SZ material comprises the following steps:

0.075mmol of 6,6 '-biphenylthiazole-2, 2' -diamine and 0.05mmol of 2,4, 6-trihydroxybenzene-1, 3, 5-triformal are placed in a 20mL heat-resistant glass tube, a mixed solvent of 0.375mL of o-dichlorobenzene and 1.125mL of 1, 4-dioxane, and 0.075mL of 6M acetic acid were added to a heat-resistant glass tube, and after ultrasonic dispersion for 5 minutes, performing degassing circulation treatment of three times of freezing, vacuumizing, filling nitrogen and unfreezing in the double-row pipe, sealing the glass pipe by flame after vacuumizing, reacting at 120 ℃ for 72h, cooling to room temperature, centrifuging the reaction system (5000r/min) to obtain reaction precipitate, cleaning the precipitate with tetrahydrofuran, and drying in an oven at 120 ℃ for one day to obtain 24.1mg of COF-SZ material with the yield of 80%. In the practical application process, the dosage can be adjusted according to the proportion, and the production scale is enlarged.

Fig. 1 shows the experimental, fitted and refined X-ray diffraction patterns of COF-SZ materials. As can be seen from fig. 1, the XRD pattern of the COF-SZ synthesized under the experimental conditions of example 1 corresponds to the peak position fitted according to the theoretical structure, and the difference between the experimental data and the refined data is relatively small by the fine modification of Pawley, and the error Rwp is 4.9%, and the Rp is 3.16% (less than 5% means that the structural similarity is high), which indicates that the COF-SZ material is successfully synthesized by the present invention.

Under the condition that other reaction conditions are not changed, the reaction temperature is set to be 90 ℃, 18.1mg of COF-SZ material can be obtained, and the yield is 60%; the reaction temperature was set at 150 ℃ to obtain 24.4mg of COF-SZ material in 81% yield.

Example 2

The preparation of COF-SZ material comprises the following steps:

placing 0.075mmol of 6,6 '-biphenylthiazole-2, 2' -diamine and 0.05mmol of 2,4, 6-trihydroxybenzene-1, 3, 5-triformal in a 20mL heat-resistant glass tube, adding a mixed solvent of 0.375mL of o-dichlorobenzene and 1.125mL of mesitylene and 0.075mL of 6M of acetic acid into the heat-resistant glass tube, ultrasonically dispersing for 5 minutes, performing degassing circulation treatment of three times of freezing, vacuumizing, filling nitrogen and unfreezing in a double-row tube, sealing the glass tube by flame after vacuumizing, reacting for 72 hours at 120 ℃, centrifuging (5000r/min) the reaction system after the temperature is reduced to room temperature to obtain reaction precipitate, cleaning the precipitate by tetrahydrofuran, and drying in an oven at 120 ℃ for one day to obtain 22mg of COF-SZ material with the yield of 73%.

Example 3

The preparation of COF-SZ-carbonized material comprises the following steps:

200mg of the COF-SZ material prepared as described in example 1 were mixed with 1g of anhydrous ZnCl₂Uniformly mixing the materials under the anhydrous and oxygen-free conditions, placing the materials in a 20mL quartz bottle, sealing the quartz bottle by using flame under the vacuum condition, heating the quartz bottle to 700 ℃ in a muffle furnace at the speed of 5 ℃/min, carrying out high-temperature treatment for 96 hours, cleaning a reaction product after the temperature is reduced to room temperature (sequentially cleaning the reaction product by using dilute hydrochloric acid, deionized water and tetrahydrofuran at the temperature of 70-80 ℃), and drying the reaction product in a 120 ℃ oven for one day to obtain 130mg of COF-SZ-carbonized material with the yield of 65%.

Fig. 2 shows the X-ray diffraction pattern of COF-SZ-carbonized material. As can be seen from FIG. 2, no visible peak exists in the XRD spectrum, which shows that the crystal structure of the original COF-SZ material does not exist after carbonization treatment, and an amorphous structure is formed.

Gas adsorption experiments and porosity analysis

The COF-SZ-carbonized material prepared in example 3 was subjected to a gas adsorption experiment and porosity analysis using a rapid specific surface area and porosity analyzer, model ASAP 2020 plus HD 88. Wherein N is₂The adsorption and desorption tests were carried out at a temperature of 77K, CO₂And N₂The adsorption experiment of (2) was carried out at a temperature of 273K. The experimental results are shown below:

the specific surface area of the COF-SZ material passes through N under the condition of 77K temperature₂The absorption and desorption curve is 1633cm²The specific surface area of the COF-SZ-carbonized material measured by a nitrogen desorption curve was 2826cm²The adsorption amount of nitrogen gas after carbonization (COF-SZ-carbonized material) of the COF-SZ material is significantly higher than that of the COF-SZ material before carbonization as shown in FIG. 3, which indicates that the COF-SZ material has higher specific surface area after carbonization.

At 273K temperature, COF-SZ material is coupled with CO₂The adsorption capacity was 62cm³G, to N₂Has an adsorption capacity of 6cm³(ii)/g; COF-SZ-carbide material pair CO₂The adsorption capacity was 96cm³G, to N₂Has an adsorption capacity of 11cm³(ii) in terms of/g. As shown in fig. 4.

The pore size distribution of the COF-SZ material and the COF-SZ-carbonized material is as shown in figure 5, the pore size distribution of the COF-SZ material is single, the size is about 3nm, and the pore size distribution is consistent with the result of a theoretical structure; the pore size of the COF-SZ material after carbonization is mainly below 6nm, and the pore size distribution is wider than that before carbonization, so that the carbonization can introduce more pores into the structure of the COF-SZ material, and the COF-SZ-carbonized material has a richer pore structure.

Example 4

The preparation of COF-SZ-carbonized material comprises the following steps:

200mg of the COF-SZ material prepared as described in example 1 were mixed with 1g of anhydrous ZnCl₂Uniformly mixing the materials under the anhydrous and oxygen-free conditions, placing the materials in a 20mL quartz bottle, sealing the quartz bottle by using flame under the vacuum condition, heating the quartz bottle to 700 ℃ in a muffle furnace at the speed of 5 ℃/min, carrying out high-temperature treatment for 2h, cooling the quartz bottle to room temperature, cleaning a reaction product (sequentially cleaning the quartz bottle by using dilute hydrochloric acid, deionized water and tetrahydrofuran at the temperature of 70-80 ℃), and drying the quartz bottle in a 120-DEG C oven for one day to obtain the COF-SZ-carbonized material with the yield of 70%. The specific surface area of the material is 2236cm measured at 77K²/g。

Assembly and testing of supercapacitors

Assembling: the method comprises the steps of assembling the conventional supercapacitor by using a conventional assembly method of a button type (CR2032) symmetrical supercapacitor, weighing active materials (COF-SZ-carbonized material prepared in example 3), carbon black and polytetrafluoroethylene according to the mass fractions of 85%, 10% and 5%, mixing the active materials, the carbon black and the polytetrafluoroethylene uniformly in a mortar, grinding the mixture into a uniform film, drying the film in a vacuum oven at 120 ℃ for 12 hours, cutting the film into small wafers with the diameter of 12mm, weighing the small wafers respectively, selecting two small wafers with similar mass as electrode plates (the content of the active materials in each electrode plate is about 3.7-4.0 mg), pressing the electrode plates on a stainless steel mesh (316L, 400 meshes and 15mm in diameter) current collector, separating the electrode plates by using glass fibers as diaphragms, and immersing the electrode plates into ionic liquid 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF)₄) In the electrolyte, the electrolyte is added with a solvent,and assembling to complete the super capacitor.

And (3) testing: the supercapacitor test was performed on an electrochemical workstation CHI 660 (the same applies to the Biologic VSP electrochemical workstation), and the cyclic voltammetry and constant current charge and discharge tests were performed at room temperature.

The experimental results are shown below:

FIG. 6 shows cyclic voltammograms of COF-SZ-carbonized materials; as can be seen from FIG. 6, the cyclic voltammetry curve has no redox peak, which indicates that the capacitance of the COF-SZ-carbonized material is mainly derived from an electric double layer capacitance, and the voltage can reach 3.5V by using an ionic liquid electrolyte. Fig. 7 and 8 show a low current constant current charge and discharge curve and a high current constant current charge and discharge curve of the COF-SZ-carbonized material, respectively; specific capacitance data (formula C ═ 2It/mV, where I is the discharge current (unit: a), t is the discharge time (unit: s), m is the mass of the carbonized COF — SZ used for one electrode (unit: g), and V is the discharge voltage (unit: V)) at each current density of the supercapacitor can be calculated from the data of fig. 7 and 8. Fig. 9 shows a graph of specific capacity of COF-SZ-carbonized materials at different current densities, and fig. 10 shows energy density-power density curves of COF-SZ-carbonized materials; as can be seen from FIGS. 9 and 10, the supercapacitor assembled from the COF-SZ-carbonized material had a capacity of 89F/g at a current density of 1A/g and an energy density of 44Kh/kg at a power density of 108W/kg, and exhibited a high rate capability (68.5% of the specific capacitance at 1A/g at a current density of 10A/g); the COF-SZ material after carbonization treatment has better conductivity, and the assembled super capacitor has higher rate performance.

Effect of the volume ratio of o-dichlorobenzene and 1, 4-dioxane on the preparation of COF-SZ Material

The invention researches the influence of o-dichlorobenzene and 1, 4-dioxane at different volume ratios on the preparation of COF-SZ material, and the preparation method of the COF-SZ material is basically the same as that of example 1, and comprises the following steps:

0.075mmol of 6,6 '-biphenylthiazole-2, 2' -diamine and 0.05mmol of 2,4, 6-trihydroxybenzene-1, 3, 5-triformal were placed in a 20mL heat-resistant glass tube, a mixed solvent of o-dichlorobenzene and 1, 4-dioxane (wherein the volume ratio of o-dichlorobenzene to 1, 4-dioxane was set to 0.75mL:0.75mL, 0.5 mL: 1mL, 0.3 mL: 1.2mL, 1.125 mL: 0.375mL) and 0.075mL of 6M acetic acid were added to the heat-resistant glass tube, and after 5 minutes of ultrasonic dispersion, the reaction system was centrifuged at 120 ℃ for 72 hours after three times of degassing cycles of freezing-evacuation-nitrogen-charging-thawing in a double-tube, followed by sealing the glass tube with a flame after evacuation, and after the temperature was lowered to room temperature (5000r/min), reaction precipitates were obtained, washed with tetrahydrofuran, and dried in an oven at 120 ℃ for one day to obtain COF-SZ materials with yields of 74%, 77%, 79%, and 69%, respectively. The COF-SZ material prepared above was subjected to X-ray diffraction comparison with the COF-SZ material prepared in example 1, and its crystallinity is shown in fig. 11; the more distinct the peak around 3 degrees indicates the better crystallinity, and by comparison, the most significant peak was found at a volume ratio of o-dichlorobenzene to dioxane of 1:3 (example 1), and hence the optimum ratio was found. This result indicates that the solvent has a large influence on the crystallinity of the product.

The foregoing is directed to preferred embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. However, any simple modification, equivalent change and modification of the above embodiments according to the technical essence of the present invention are within the protection scope of the technical solution of the present invention.