High-hygroscopicity MOFs material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of water adsorption, and particularly relates to a high-hygroscopicity MOFs (Metal-Organic Frameworks) material as well as a preparation method and application thereof. The preparation method of the high-hygroscopicity MOFs material comprises the following steps: dissolving a surfactant in water to form a micelle system, then adding a mediating salt, a Zr salt, a crystal growth regulator, mesitylene and an organic ligand, and carrying out micelle and precursor co-assembly and post-treatment under stirring and heating conditions to prepare the MOFs material, the surfactant is a triblock copolymer F127; the organic ligand is 2-aminoterephthalic acid. The MOFs material prepared by the method can form an ordered mesoporous structure, can reach the maximum adsorption value more quickly, and has excellent moisture absorption dynamic performance; in addition, the fabric also has higher moisture absorption capacity.

Description

Technical Field

[0001] This invention belongs to the technical field of water adsorption, and more specifically, relates to a highly hygroscopic MOF material, its preparation method, and its application. Background Technology

[0002] The core of adsorption-based air-to-water extraction technology lies in the design of the hygroscopic material, whose hygroscopic kinetics and capacity directly determine the system's water production efficiency. Among numerous candidate adsorption materials, metal-organic frameworks (MOFs) have attracted considerable attention due to their lower adsorption humidity requirements and mild desorption temperatures.

[0003] However, traditional MOF materials typically have a narrow microporous structure, which leads to two significant drawbacks: on the one hand, it restricts the diffusion of water molecules within the pores, reducing the hygroscopic kinetics; on the other hand, it restricts the accessibility of internal adsorption sites, thereby reducing the hygroscopic capacity.

[0004] To address the limitations on mass transfer and adsorption capacity caused by microporous structures, constructing well-connected mesoporous mass transfer channels in traditional hygroscopic MOFs has become a key approach to improving their overall water adsorption performance. However, most existing methods for introducing mesoporous structures into MOFs rely on a two-step process combining high-temperature hydrothermal synthesis and subsequent treatment. This process is not only cumbersome and time-consuming, but also often requires large amounts of organic solvents and consumes significant energy during synthesis, increasing both environmental burden and the cost and complexity of large-scale production. Furthermore, the mesopores constructed by these methods often exhibit disordered and non-uniform morphologies with wide pore size distributions and uncontrollable structures, making it difficult to precisely optimize moisture transport paths. Therefore, the improvement in the material's hygroscopic kinetics and capacity is limited, restricting its practical application in high-efficiency air-to-water systems.

[0005] In the current preparation process of MOF materials, nonionic surfactant P123 is used to control the crystal morphology, particle size and pore size of MOF materials. However, it is still impossible to form an ordered mesoporous structure, and it is difficult to achieve precise optimization of the moisture transport path. Therefore, the effect on improving the material's moisture absorption kinetics and capacity is limited.

[0006] Therefore, developing a method for preparing MOFs materials with regular and ordered mesoporous structures under mild conditions using water as the main solvent has become an urgent technical problem to be solved. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, the primary objective of this invention is to provide a method for preparing highly hygroscopic MOF materials. The prepared MOF materials can form an ordered mesoporous structure, reach their maximum adsorption value more quickly, and exhibit excellent hygroscopic kinetics; furthermore, they also possess higher hygroscopic capacity.

[0008] The second objective of this invention is to provide a highly hygroscopic MOF material prepared by the above-described preparation method.

[0009] The third objective of this invention is to provide applications of highly hygroscopic MOFs materials in the fields of water adsorption, gas adsorption and separation, and gas storage.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0011] This invention claims protection for a method for preparing a highly hygroscopic MOF material, comprising the following steps: Surfactants were dissolved in water to form a micelle system. Then, mediating salt, Zr salt, crystal growth regulator, mesitylene and organic ligands were added. The micelles and precursors were co-assembled under stirring and heating conditions. After post-processing, MOF materials were prepared. The surfactant is a triblock copolymer F127; the organic ligand is 2-aminoterephthalic acid.

[0012] In this invention, a specific surfactant, triblock copolymer F127, is combined with mesitylene. The combined action of these two agents promotes the formation of an ordered mesoporous structure in MOF materials, thereby enhancing the water adsorption kinetics and moisture absorption capacity of the MOFs. Specifically, triblock copolymer F127 acts as a soft template, and mesitylene acts as a swelling agent to induce the self-assembly of the surfactant, forming cylindrical micelles. The MOFs then use these cylindrical micelles as templates to further grow into ordered mesoporous MOF materials. This ordered mesoporous structure reduces the Knudsen diffusion resistance of water molecules within its pores, allowing water molecules to reach the adsorption sites inside the MOFs more easily and quickly, thus improving the water adsorption kinetics and water adsorption capacity of the MOF materials.

[0013] In this invention, the use of a mediating salt enables the formation of MOF materials under low-temperature aqueous conditions. The mediating salt increases the solubility of organic ligands in the aqueous phase through the Hofmeister effect, while simultaneously promoting the proximity of organic ligands and metal ions, thereby facilitating the self-assembly of MOF materials through coordination bonds. Meanwhile, the crystal growth regulator, by competing with the organic ligands for coordination sites with metal ions, inhibits the nucleation rate and reduces the number of crystal nuclei, thus promoting the continuous growth of individual crystal nuclei and resulting in crystals with higher crystallinity and more uniform size.

[0014] Through the adjustment of the above process, the present invention achieves the controllable preparation of ordered mesoporous channels with uniform pore size and regular arrangement. This structure provides water molecules with an efficient and continuous diffusion path, significantly improving the accessibility of adsorption sites of MOFs materials, thereby simultaneously optimizing the hygroscopic kinetics and equilibrium adsorption capacity of the materials.

[0015] Compared with existing technologies that rely on high-temperature hydrothermal synthesis and organic solvents, this invention achieves the green synthesis of ordered mesoporous MOFs in a low-temperature aqueous system. This method eliminates the need for high-temperature and high-pressure conditions and avoids the extensive use of organic solvents, significantly reducing energy consumption and environmental burden, demonstrating excellent energy-saving and environmentally friendly characteristics and potential for large-scale production.

[0016] This invention achieves in-situ construction of ordered mesoporous structures through a one-step co-assembly of micelles and precursors. This one-step synthesis process significantly simplifies the production process, eliminates the post-processing steps in traditional methods, effectively shortens the overall preparation cycle, and improves synthesis efficiency, providing a technological foundation for the large-scale and stable production of high-performance ordered mesoporous MOFs.

[0017] Preferably, the mass ratio of the surfactant to water is 1:60-90. More preferably, the mass ratio of the surfactant to water is 1:70-80.

[0018] Preferably, the volume concentration of mesitylene in the micelle system is 3-20%. More preferably, the volume concentration of mesitylene in the micelle system is 5-15%. More preferably, the volume concentration of mesitylene in the micelle system is 5-8%.

[0019] Preferably, the mediating salt is selected from one of NaClO4·H2O, NaI, NaNO3, and NaCl; and / or the molar ratio of the surfactant to the mediating salt is 1:300-400. Specifically, the molar ratio of the surfactant to the mediating salt is 1:340-380. More specifically, the molar ratio of the surfactant to the mediating salt is 1:350-360.

[0020] Preferably, the Zr salt is selected from one of ZrOCl2·8H2O, ZrO(NO3)2·2H2O, Zr(NO3)4·5H2O, and ZrCl4; and / or the molar ratio of the surfactant to the Zr salt is 1:100-200. Specifically, the molar ratio of the surfactant to the Zr salt is 1:150-170. Specifically, the molar ratio of the surfactant to the Zr salt is 1:160-168.

[0021] Preferably, the crystal growth regulator is selected from at least one of acetic acid and formic acid; and / or the volume concentration of the crystal growth regulator in the micelle system is 4-6%.

[0022] Preferably, the stirring speed is 800-1200 rpm; and / or the heating temperature is 40-60℃.

[0023] Preferably, the post-processing involves solvent exchange of the prepared product followed by activation treatment.

[0024] Preferably, in some specific embodiments, the solvent exchange operation is as follows: (1) The obtained product was dispersed in N,N-dimethylformamide and subjected to multiple solid-liquid separations; (2) Disperse the product from step (1) in ethanol and perform solid-liquid separation multiple times; (3) Soak the product from step (2) in ethanol and change the ethanol several times.

[0025] Preferably, in steps (1) and (2), the solid-liquid separation is performed 2-5 times.

[0026] Preferably, in step (3), the ethanol is replaced 1-2 times a day.

[0027] Preferably, the activation treatment involves drying the product at 60°C under vacuum. More preferably, the drying time is 5-10 hours.

[0028] Furthermore, this invention seeks protection for the highly hygroscopic MOFs material prepared by the above-described preparation method.

[0029] Furthermore, this invention seeks protection for the application of the above-mentioned highly hygroscopic MOFs materials in the fields of water adsorption, gas adsorption and separation, and gas storage.

[0030] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a specific surfactant, triblock copolymer F127, in combination with mesitylene. The combined action of these two agents promotes the formation of an ordered mesoporous structure in MOF materials, thereby enhancing the water adsorption kinetics and hygroscopic capacity of the MOFs. The use of a mediating salt enables the formation of MOF materials under low-temperature aqueous conditions, while the use of a crystal growth regulator facilitates better crystal growth and shaping of the MOFs. Through adjustments to the above processes, this invention achieves the controllable fabrication of ordered mesoporous channels with uniform pore size and regular arrangement. This structure provides an efficient and continuous diffusion path for water molecules, significantly improving the accessibility of adsorption sites in the MOF materials, thus simultaneously optimizing the hygroscopic kinetics and equilibrium adsorption capacity of the materials. Attached Figure Description

[0031] Figure 1Scanning electron microscope (SEM) and transmission electron microscope (TEM) images of UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2 are shown. Figure 1 In the image, a and b are the SEM and TEM images of UiO-66-NH2, respectively. Figure 1 c and d in the image are SEM and TEM images of UiO-66-NH2-PT, respectively; Figure 1 In the image, e and f are the SEM and TEM images of UiO-66-NH2-F, respectively. Figure 1 In the image, g and h are the SEM and TEM images of OM-UiO-66-NH2, respectively.

[0032] Figure 2 Powder X-ray diffraction (PXRD) patterns of UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F and OM-UiO-66-NH2.

[0033] Figure 3 Nitrogen adsorption-desorption curves for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2.

[0034] Figure 4 The BJH pore size distribution curves are for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2.

[0035] Figure 5 Small-angle X-ray scattering (SAXS) diagrams for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2.

[0036] Figure 6 Normalized kinetic curves of water adsorption for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F and OM-UiO-66-NH2.

[0037] Figure 7 The water adsorption isotherms for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F and OM-UiO-66-NH2 are given. Detailed Implementation

[0038] The present invention will be further described below with reference to the specification and specific embodiments, but the embodiments do not limit the present invention in any way. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in this technical field.

[0039] Example 1: Highly Hygroscopic MOF Materials (1) 75 mg of surfactant F127 (Sigma-Aldrich, CAS: 9003-11-6) was dissolved in 6 mL of ultrapure water to form a micelle system. Then, 0.3 g of mediating salt NaClO4·H2O and 0.32 g of metal salt ZrOCl2·8H2O were added and stirred until completely dissolved. Then, crystal growth regulators acetic acid and mesitylene were added sequentially to make their volume concentrations in the micelle system 15% and 5%, respectively. The mixture was stirred at 40 °C and 1000 rpm for 15 min to fully homogenize it. Finally, 0.1 g of organic ligand 2-aminoterephthalic acid was added, and the reaction was continued for 16 h at the same temperature and stirring speed.

[0040] (2) The product obtained in step (1) was centrifuged (centrifugation speed was 10,000 rpm, temperature was room temperature, and time was 10 min; the following centrifugation operations were carried out under the same process conditions), and the solid component was collected. First, the solid component was completely dispersed in N,N-dimethylformamide, and the process was repeated 3 times after centrifugation; then it was completely dispersed in ethanol, and the process was repeated 3 times after centrifugation; finally, the solid component was completely dispersed in ethanol at 60℃ and soaked for 2 days, with the ethanol being changed once a day. After soaking, it was centrifuged again to obtain the solid product.

[0041] (3) The solid product obtained in step 2 was dried at 60°C and under vacuum for 8 h to completely remove the residual solvent molecules in the pores and obtain a highly hygroscopic MOF material (OM-UiO-66-NH2).

[0042] Comparative Example 1 The difference between this comparative example and Example 1 is that in step (1), surfactant F127 was replaced with P123 (Sigma Aldrich, CAS: 9003-11-6) to prepare MOF material (UiO-66-NH2-PT).

[0043] Comparative Example 2 The difference between this comparative example and Example 1 is that in step (1), mesitylene is not added to prepare MOFs material (UiO-66-NH2-F).

[0044] Comparative Example 3 The preparation method of UiO-66-NH2 synthesized by the traditional hydrothermal method includes the following steps: 58 mg of zirconium tetrachloride, 1.29 mL of acetic acid, and 20 μL of hydrochloric acid were added to 9 mL of N,N-dimethylformamide. After ultrasonic dissolution, 46 mg of 2-aminoterephthalic acid was added to the mixture. The mixture was then sealed in a polytetrafluoroethylene-lined autoclave and heated in an oven at 120 °C for 24 h. After cooling to room temperature, the synthesized UiO-66-NH2 crystals were collected by centrifugation, then washed twice with N,N-dimethylformamide, and then twice with ethanol (the centrifugation and washing procedures are as described in step (2) of Example 1). Finally, the crystals were dried in a vacuum oven at 60 °C for 12 h to obtain UiO-66-NH2.

[0045] Test Example 1 The synthesized UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2 were tested using scanning electron microscopy and transmission electron microscopy.

[0046] Figure 1 Scanning electron microscope (SEM) and transmission electron microscope (TEM) images of UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2. Figure 1 As shown in a and b, the SEM image of UiO-66-NH2 reveals no obvious mesoporous morphology on its surface, and no corresponding bright mesoporous regions were found in the TEM image. Figure 1 As shown in c and d, the SEM image of UiO-66-NH2-PT reveals only a few pits on the surface (marked with yellow circles), with no clear mesoporous structure; the TEM image shows localized bright circular areas (marked with yellow circles) corresponding to the surface pits. Figure 1 As can be seen from e and f in the image, the SEM image of UiO-66-NH2-F shows relatively blurry mesoporous signs, while its TEM image shows bright areas corresponding to spherical mesoporous structures. Figure 1 As can be seen from g and h, the SEM image of OM-UiO-66-NH2 shows obvious mesoporous arrangement, and the TEM image shows bright areas (marked by yellow lines) corresponding to cylindrical mesoporous channels, indicating that there may be an ordered mesoporous structure in this material.

[0047] Test Example 2 Powder X-ray diffraction (PXRD) tests were performed on the synthesized UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2. The test conditions were: Cu Kα radiation (λ = 1.5406 Å, tube voltage 40 kV, tube current 40 mA), at room temperature and atmospheric pressure, at a frequency of 10°·min. 1 The scanning rate is performed within the range of 2θ = 3-50°.

[0048] Figure 2 Powder X-ray diffraction patterns of UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2. Figure 2 It can be seen that the PXRD spectra of UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2 in the range of 2θ = 3-50° are basically consistent with the simulated spectra of UiO-66-NH2 and UiO-66-NH2, indicating that all three materials retain the inherent crystal structure and phase composition of UiO-66-NH2. Among them, only OM-UiO-66-NH2 showed an additional weak diffraction peak at 2θ ≈ 4.4°, suggesting that there may be an ordered mesoporous structure in the material.

[0049] Test Example 3 Nitrogen adsorption-desorption tests were conducted on UiO-66-NH2-PT, UiO-66-NH2-F, OM-UiO-66-NH2, and UiO-66-NH2. The test conditions were as follows: the determination was carried out at liquid nitrogen temperature (77 K), the mass of the sample used was controlled within 100 mg, and the sample was activated by heating under vacuum at 100 °C for 12 h before the test to remove the gas already adsorbed inside the material.

[0050] Figure 3 The nitrogen adsorption-desorption curves are for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2. Figure 3 As shown, UiO-66-NH2-PT and UiO-66-NH2 exhibit relatively flat adsorption curves in the P / P0 range of 0.05-0.97, and no obvious hysteresis loop is observed, indicating that they do not possess significant mesoporous characteristics. In contrast, UiO-66-NH2-F exhibits a subtle H4-type hysteresis loop in the P / P0 range of 0.45-0.77, while OM-UiO-66-NH2 shows a more obvious H4-type hysteresis loop in the P / P0 range of 0.45-0.80, further confirming the presence of mesoporous structures in both materials.

[0051] Test Example 4 Based on the nitrogen adsorption-desorption data from Test Example 3, BJH pore size analysis was performed on UiO-66-NH2-PT, UiO-66-NH2-F, OM-UiO-66-NH2, and UiO-66-NH2.

[0052] Figure 4 The BJH pore size distribution curves are shown for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2. Figure 4 It can be seen that no obvious mesoporous peaks were observed in the pore size distribution curves of UiO-66-NH2-PT and UiO-66-NH2, indicating that neither material possesses significant mesoporous characteristics. Further analysis shows that the most probable pore size of UiO-66-NH2 is approximately 5.6 nm, while the most probable pore size of OM-UiO-66-NH2 is located at approximately 11 nm, confirming that both materials possess a mesoporous structure.

[0053] Test Example 5 SAXS tests were performed on UiO-66-NH2-PT, UiO-66-NH2-F, OM-UiO-66-NH2, and UiO-66-NH2 under the following conditions: the distance from the sample to the detector was 1200 mm and the exposure time was 300 s.

[0054] Figure 5 Small-angle X-ray scattering patterns for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2. Figure 5 It can be seen that no obvious scattering signal was observed in the small-angle X-ray scattering patterns of UiO-66-NH2-PT and UiO-66-NH2. UiO-66-NH2-F showed only a weak scattering peak, and its scattering vectors did not exhibit a typical proportional relationship, indicating that this material does not possess an ordered mesoporous structure. In contrast, the small-angle X-ray scattering patterns of OM-UiO-66-NH2 showed significant differences at scattering vectors q = 0.253, 0.438, and 0.507 nm. 1 Three characteristic scattering peaks are displayed at this point, with a q-value ratio of approximately 1: :2, corresponding to the (100), (110) and (200) crystal plane diffraction of the two-dimensional hexagonal mesoporous structure, respectively, confirming that an ordered two-dimensional hexagonal mesoporous structure is formed in the material.

[0055] Based on the above characterization results, it can be confirmed that an ordered mesoporous structure has been successfully constructed in the OM-UiO-66-NH2 material. The inventors discovered that the surfactants F127 and mesitylene play crucial roles in the formation of this structure. Replacing F127 with P123, which has a longer hydrophobic chain, reduces the packing parameter, resulting in insufficient driving force for micelle self-assembly (corresponding to UiO-66-NH2-PT). Similarly, without using mesitylene to swell the hydrophobic ends of F127 to increase its volume, the small packing parameter also prevents effective micelle self-assembly (corresponding to UiO-66-NH2-F). Therefore, neither UiO-66-NH2-PT nor UiO-66-NH2-F can form an ordered mesoporous structure.

[0056] Test Example 6 Hygroscopic kinetics were tested on UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F and OM-UiO-66-NH2. The test conditions were: adsorption test at 25℃ and 30% relative humidity. All samples were activated for 12 h in a nitrogen atmosphere at 100℃ and 1% relative humidity before the test to ensure that the pre-adsorbed moisture on the material surface and in the pores was completely removed.

[0057] Figure 6 Normalized kinetic curves for water adsorption of UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2 are shown. Figure 6 The normalized adsorption kinetics curves of OM-UiO-66-NH2 show that it reaches adsorption equilibrium in approximately 46 minutes, while UiO-66-NH2-F requires 56 minutes, UiO-66-NH2-PT requires 63 minutes, and UiO-66-NH2 requires 154 minutes. The adsorption equilibrium time of OM-UiO-66-NH2 is only about one-third that of UiO-66-NH2, and significantly faster than that of UiO-66-NH2-F and UiO-66-NH2-PT. This indicates that the ordered mesoporous structure can efficiently enhance water adsorption kinetics, demonstrating that the OM-UiO-66-NH2 prepared in this invention possesses excellent hygroscopic kinetics and can reach its maximum adsorption value more quickly.

[0058] Test Example 7 The moisture absorption capacity of UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F and OM-UiO-66-NH2 was tested. The test conditions were as follows: the adsorption test was carried out at a temperature of 25℃. All samples were activated for 12 h in a nitrogen atmosphere at 100℃ and 1% relative humidity before the test to ensure that the moisture pre-adsorbed on the material surface and in the pores was completely removed.

[0059] Figure 7 These are the water adsorption isotherms for UiO-66-NH2, UiO-66-NH2-PT, UiO-66-NH2-F, and OM-UiO-66-NH2. For example... Figure 7 As shown, for OM-UiO-66-NH2, its water absorption reaches 0.15 g·g at a relative humidity of 10%. 1 Compared to UiO-66-NH2-F, the water absorption is increased by approximately 11%; compared to UiO-66-NH2-PT, it is increased by approximately 42%; and compared to UiO-66-NH2, it is increased by approximately 150%. At a relative humidity of 20%, the water absorption increases to 0.33 g·g. 1 Compared to UiO-66-NH2-F, the water absorption capacity is increased by approximately 12%, compared to UiO-66-NH2-PT by approximately 42%, and compared to UiO-66-NH2 by approximately 136%; at a relative humidity of 30%, the water absorption capacity is further increased to 0.43 g·g. 1 The improvement compared to UiO-66-NH2-F, UiO-66-NH2-PT, and UiO-66-NH2 was further weakened, but it was still about 12% higher than UiO-66-NH2. Therefore, OM-UiO-66-NH2 exhibits significantly better moisture absorption capacity than UiO-66-NH2-F, UiO-66-NH2-PT, and UiO-66-NH2 in the low humidity range (relative humidity 0-30%, especially 10-20%). Combined with the above characterization and test results, it is fully demonstrated that the prepared ordered mesoporous MOF material OM-UiO-66-NH2 has faster moisture absorption kinetics and higher moisture absorption capacity.

Claims

1. A method for preparing a highly hygroscopic MOF material, characterized in that, Includes the following steps: Surfactants were dissolved in water to form a micelle system. Then, mediating salt, Zr salt, crystal growth regulator, mesitylene and organic ligands were added. The micelles and precursors were co-assembled under stirring and heating conditions. After post-processing, MOF materials were prepared. The surfactant is a triblock copolymer F127; the organic ligand is 2-aminoterephthalic acid.

2. The preparation method according to claim 1, characterized in that, The mass ratio of the surfactant to water is 1:60-90.

3. The preparation method according to claim 1, characterized in that, The volume concentration of the mesitylene in the micelle system is 3-20%.

4. The preparation method according to claim 1, characterized in that, The mediating salt is selected from one of NaClO4·H2O, NaI, NaNO3, and NaCl; and / or The molar ratio of the surfactant to the mediating salt is 1:300-400.

5. The preparation method according to claim 1, characterized in that, The Zr salt is selected from one of ZrOCl2·8H2O, ZrO(NO3)2·2H2O, Zr(NO3)4·5H2O, and ZrCl4; and / or the molar ratio of the surfactant to the Zr salt is 1:100-200.

6. The preparation method according to claim 1, characterized in that, The crystal growth regulator is selected from at least one of acetic acid and formic acid; and / or the volume concentration of the crystal growth regulator in the micelle system is 4-6%.

7. The preparation method according to claim 1, characterized in that, The stirring speed is 800-1200 rpm; and / or The heating temperature is 40-60℃.

8. The preparation method according to claim 1, characterized in that, The post-processing involves solvent exchange of the prepared product followed by activation.

9. The highly hygroscopic MOF material prepared by the preparation method according to any one of claims 1-8.

10. The application of the highly hygroscopic MOFs material according to claim 9 in the fields of water adsorption, gas adsorption separation, and gas storage.

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