Submicron py-tpa cof monocrystal sheet and preparation method thereof
Submicron Py-TPA COF single crystal wafers were prepared by solvothermal reaction and acetic acid solution formulation, solving the problem of preparing large-size non-uniform single crystals in the prior art, achieving high yield and morphological uniformity, and improving the application performance of single crystals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- INST OF CHEM CHINESE ACAD OF SCI
- Filing Date
- 2024-11-29
- Publication Date
- 2026-05-29
AI Technical Summary
Existing technologies are difficult to efficiently prepare large-size, uniform Py-TPA COF single crystals, and the preparation process is time-consuming, labor-intensive, and has low yield, making it difficult to meet the requirements for single crystal analysis and morphology control.
Submicron Py-TPA COF single crystal wafers were prepared by using a solvothermal reaction combined with the ratio of acetic acid solution and mesitylene, controlling the reaction temperature and time, and through anhydrous methanol extraction and drying steps. The reaction time was short and the yield was high.
It achieves morphological and dimensional uniformity of submicron Py-TPA COF single crystal wafers, improves the efficiency and application performance of single crystal analysis, and has high specific surface area and regular channel structure, making it suitable for single crystal X-ray diffraction and efficient molecular transport.
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Figure CN122103491A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of materials, specifically to a submicron Py-TPA COF single crystal wafer and its preparation method. Background Technology
[0002] Py-TPA COF is prepared by the condensation of tetra-(4-aminophenyl)pyrene and terephthalaldehyde. In 2016, Thomas Bein's research group demonstrated that the three-dimensional conformation of Py facilitates the formation of well-defined stacking sites, making it easy to prepare large-sized crystals, with Py-TPA COF reaching crystal sizes of 300-500 nm. Due to its high specific surface area and porosity, it can be applied to water vapor adsorption; and due to the protonation of imine bonds, it can also be applied to acid sensing.
[0003] Currently, the main methods for preparing Py-TPA COFs include solvothermal methods, room temperature methods, and ultrasonic methods. The prepared crystals are mostly polycrystalline powders with non-uniform sizes or irregular morphologies. Due to incomplete reactions, mixtures or inclusion compounds of crystals and amorphous materials may even exist. Many research groups are attempting to prepare single crystals of 2D COFs and control their morphology. The former is important for determining their structure, while the latter is crucial for improving their application performance. Single crystal preparation mainly relies on the introduction of regulators to control the reaction rate, thereby preparing crystals suitable for single-crystal analysis. Morphology control can currently be achieved through solvents and catalysts.
[0004] The preparation of single crystals allows for precise analysis of the structure of COFs, which is crucial for understanding the physicochemical properties of materials and designing novel functional materials. For example, it allows for the determination of precise pore size, porosity, and channel structure, which is particularly important for gas adsorption and separation. Single crystals typically exhibit better thermal and chemical stability, making them more reliable for applications under harsh conditions. Furthermore, the more regular porosity of single-crystal COFs facilitates efficient molecular transport and separation. For optoelectronic applications, single-crystal COFs, due to their regular pore structure and extended π-conjugated system, exhibit optical, electrical, and optoelectronic properties. For instance, introducing aggregation-induced emission groups or chromophores into the framework can achieve photovoltaic behavior. The regular channel structure of single-crystal COFs facilitates efficient host-guest interactions, which is particularly important for catalytic reactions. The regular channel structure can improve the mass transfer capacity between reactants and products, thereby increasing the reaction rate.
[0005] The preparation of large-size 2D COF single crystals for single-crystal X-ray diffraction is currently quite challenging, mainly due to the need to control the reaction rate to allow the crystal to grow slowly, which is time-consuming, labor-intensive, and results in a relatively low yield. Summary of the Invention
[0006] The purpose of this invention is to provide a submicron Py-TPA COF single crystal wafer and its preparation method. The method of this invention has a short reaction time, high reaction yield, and the prepared submicron Py-TPA COF single crystal wafer has relatively uniform morphology and size.
[0007] The present invention first provides a method for preparing Py-TPA COF single crystal wafer, comprising the following steps: mixing tetra-(4-aminophenyl)pyrene, terephthalaldehyde, mesitylene and acetic acid solution, and carrying out a solvothermal reaction to obtain the Py-TPACOF single crystal wafer.
[0008] In the above preparation method, the molar ratio of tetra-(4-aminophenyl)pyrene to terephthalaldehyde is 1:1 to 1:4; specifically, it can be 1:2.
[0009] In the above preparation method, the amount of mesitylene added is 25-75 mL / mmol tetra-(4-aminophenyl)pyrene; specifically, it can be 50 mL / mmol tetra-(4-aminophenyl)pyrene.
[0010] In the above preparation method, the concentration of the acetic acid solution is 3-9M, specifically 6M; The volume of the acetic acid solution is 0.08-0.12 times the volume of mesitylene, specifically 0.1 times.
[0011] In the above preparation method, the solvothermal reaction is carried out in an inert atmosphere; The temperature of the solvothermal reaction is room temperature - 120°C; preferably 120°C. The solvothermal reaction takes 2-4 days; preferably 3 days.
[0012] The room temperature is known to those skilled in the art and is generally 15-35°C.
[0013] The above preparation method also includes the steps of extracting with anhydrous methanol and drying after solvothermal reaction.
[0014] Drying temperature and time: 90℃-120℃, the time depends on the amount of product, and generally requires about one day of vacuum drying.
[0015] In one embodiment of the present invention, the solvothermal reaction is carried out in a polymerization tube; the system is subjected to freeze-drying circulation before the reaction to remove air from the system.
[0016] The reaction of this invention is not limited to polymerization tubes, but can also be carried out in containers under normal pressure, which is more conducive to large-scale preparation; the reaction temperature is not limited to 120°C, and theoretically it is feasible from room temperature to 120°C; the size of the single crystal can be controlled by other conditions, such as temperature, type and amount of catalyst, and addition of regulators.
[0017] The present invention further provides a Py-TPA COF single crystal wafer prepared by the above preparation method.
[0018] The specific surface area of the Py-TPA COF single crystal is 1905 cm². 2 / g; its morphology is nanosheets of about 300nm.
[0019] The present invention has the following advantages: (1) In the prior art, it is difficult to realize single crystals that can be directly used for single crystal diffraction. Therefore, the submicron level single crystal wafer prepared by the present invention provides another possibility for resolving crystal structures. (2) By controlling the reaction conditions, the present invention has prepared submicron Py-TPA COF single crystal wafers with relatively uniform morphology and size in a short time with high yield; (3) The preparation method of the present invention has a short reaction time and a high reaction yield, which can reach a yield of more than 80%. Attached Figure Description
[0020] Figure 1 Infrared spectrum of Py-TPA COF single crystal; Figure 2 Solid-state NMR for Py-TPA COF single crystal wafers; Figure 3 PXRD and simulated stacking structure of Py-TPA COF single crystal wafer; Figure 4 The adsorption-desorption curves of the Py-TPA COF single crystal are shown. Figure 5 SEM image of a Py-TPA COF single crystal wafer; Figure 6 This is a TEM image of a Py-TPA COF single crystal wafer. Detailed Implementation
[0021] The present invention will be further described in detail below with reference to specific embodiments. The embodiments given are only for illustrating the present invention and are not intended to limit the scope of the present invention.
[0022] Unless otherwise specified, the experimental methods described in the following examples are conventional methods.
[0023] In the quantitative experiments in the following examples, three replicate experiments were set up, and the average value of the results was taken.
[0024] Unless otherwise specified, all materials and reagents used in the following examples are commercially available.
[0025] Example 1
[0026] Tetra-(4-aminophenyl)pyrene (Py) (0.04 mmol, CAS: 1610471-69-6) and terephthalaldehyde (TPA) (0.08 mmol) were placed in a polymerization tube, 2 mL of mesitylene solvent was added, followed by 0.2 mL of 6 M acetic acid solution. After ultrasonic mixing, the mixture was subjected to three freeze-dry cycles and the tube was sealed (the reaction system was frozen with liquid nitrogen, and then the system was evacuated with a pump to remove air and prevent the monomers from being oxidized and deteriorated during the reaction). The reaction was carried out at 120 °C for 3 days. After the reaction, the product was extracted with anhydrous methanol (thoroughly washed at 30-40 °C above the boiling point of methanol to remove unreacted monomers or oligomers) and dried at 90 °C to obtain 27.8 mg of yellow powder Py-TPA COF single crystal wafers, with a yield of approximately 85%.
[0027] Yield = (actual product mass / theoretical product mass) × 100%, where the theoretical product mass is based on the mass of the product obtained by dehydration after the reaction of the two monomers in the molar ratio.
[0028] Figure 1 Infrared spectrum of Py-TPA COF single crystal; by Figure 1 It can be seen that the characteristic peaks corresponding to Py and TPA have significantly disappeared or weakened, combined with the 1623 cm⁻¹ peak. -1 The presence of an imine bond indicates that the reaction proceeded relatively fully and that an imine bond was formed.
[0029] Figure 2 Solid-state NMR of Py-TPA COF single crystal wafers; the results show that solid-state NMR assigned its characteristic peaks, with approximately 156 ppm corresponding to imine carbon, proving the formation of Schiff base structure.
[0030] Figure 3 The PXRD and simulated stacking structure of the Py-TPA COF single crystal are shown; the results show that the Py-TPA COF single crystal is eclipsed rather than staggered, and the crystallization is very good.
[0031] Figure 4 The adsorption-desorption curves of the Py-TPA COF single crystal are shown; the results indicate that its specific surface area is as high as 1905 cm². 2 / g.
[0032] Figure 5 The images show SEM images of Py-TPA COF single crystal wafers; the results show that the morphology consists of nanosheets of about 300 nm, with high phase purity and relatively uniform size.
[0033] Figure 6The image shows a TEM image of a Py-TPA COF single crystal wafer; the results show that they are all single-crystal nanosheets, and some exhibit moiré patterns due to the stacking of the single crystal wafers.
Claims
1. A method for preparing a Py-TPA COF single crystal wafer, comprising the following steps: mixing tetra-(4-aminophenyl)pyrene, terephthalaldehyde, mesitylene and acetic acid solution, and carrying out a solvothermal reaction to obtain the Py-TPA COF single crystal wafer.
2. The preparation method according to claim 1, characterized in that: The molar ratio of tetra-(4-aminophenyl)pyrene to terephthalaldehyde is 1:1 to 1:
4.
3. The preparation method according to claim 2, characterized in that: The molar ratio of tetra-(4-aminophenyl)pyrene to terephthalaldehyde is 1:
2.
4. The preparation method according to any one of claims 1-3, characterized in that: The amount of mesitylene added is 25-75 mL / mmol tetra-(4-aminophenyl)pyrene.
5. The preparation method according to claim 4, characterized in that: The amount of mesitylene added was 50 mL / mmol tetra-(4-aminophenyl)pyrene.
6. The preparation method according to any one of claims 1-5, characterized in that: The concentration of the acetic acid solution is 3-9M; The volume of the acetic acid solution is 0.08-0.12 times the volume of mesitylene.
7. The preparation method according to claim 6, characterized in that: The concentration of the acetic acid solution is 6M; The volume of the acetic acid solution is 0.1 times the volume of mesitylene.
8. The preparation method according to any one of claims 1-7, characterized in that: The solvothermal reaction is carried out in an inert atmosphere; The temperature of the solvothermal reaction is room temperature - 120°C; The solvothermal reaction takes 2-4 days; preferably 3 days.
9. The preparation method according to any one of claims 1-8, characterized in that: The preparation method further includes the steps of methanol extraction and drying after solvothermal reaction.
10. A Py-TPA COF single crystal wafer prepared by the preparation method according to any one of claims 1-9.