Mesoporous MOF optical storage material and preparation method and application thereof

Abstract

The invention discloses a mesoporous MOF optical storage material and a preparation method and application thereof, and belongs to the technical field of optical information storage. According to the method disclosed by the invention, the metal salt, the ZrOCl2. 8H2O and the carboxylic acid compound solvent are adopted as raw materials, and different organic ligands are arranged, so that the pore size can be gradually increased by adjusting the structures of the organic ligands, a controllable and adjustable optical information storage system is realized, and a new MOF system is formed; when the MOF system is used for storing optical information, not only can the loading capacity of the monomers and the photoinitiators be optimized, but also more types of photoinitiators and monomers can be loaded, the diffusion efficiency of the monomers and the photoinitiators in the MOF is improved, and the uniform distribution of the photoinitiators is enhanced, so that the uniformity of photopolymerization reaction is ensured, and the photopolymerization efficiency is improved. The reliability and stability of information storage are improved, higher storage efficiency and longer storage life are achieved, and the technical problem that an existing material is poor in optical storage effect is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical information storage, and particularly relates to a mesoporous MOF optical storage material, a preparation method thereof, and an application thereof. Background Art

[0002] At present, optical information storage technology has important application prospects in aspects such as high-density storage, data security, and fast reading and writing. Traditional optical information storage mainly relies on organic dyes, polymer materials, or inorganic semiconductor materials, but these materials usually have the following defects: 1) Poor storage stability: Organic dyes are easily affected by photoaging and the environment, resulting in the attenuation of stored information over time. This attenuation affects the long-term preservation of information, especially under adverse environmental conditions such as high temperature and high humidity, and the lifespan of the storage material is greatly shortened. 2) Limited storage density: Traditional optical storage methods mainly rely on the single-photon absorption mechanism, and the information storage accuracy is limited. Due to the influence of the optical diffraction limit, the minimum unit size of the stored information is relatively large, restricting the storage capacity of the memory. 3) Poor adjustability of information storage: The storage characteristics of polymer materials or inorganic semiconductor materials are difficult to regulate, and the writing and erasing processes of stored information are relatively complex, making it difficult to meet the requirements of high-precision information storage and encryption. Low energy utilization rate: Many traditional optical storage materials have a low utilization rate of light energy during the storage process, and a high-energy light source is required to write the stored information, resulting in high system energy consumption.

[0003] Traditional optical information storage methods based on organic dyes usually use free dye molecules dispersed in a polymer matrix or a glass matrix, and the optical storage information mainly relies on the photochromic or photoisomerization effect of the organic dye. However, the distribution of these free dye molecules in the matrix is easily affected by diffusion, photobleaching, or environmental factors, resulting in poor stability of the stored information and a gradual decline in storage performance during multiple reading and writing processes. Another method that has been studied is to use MOF-5 and D-MOF for optical information storage. These materials can achieve information storage under the action of a laser by loading a photoinitiator and a monomer. However, the pore channels of MOF-5 and DMOF are relatively small, restricting the loading amount of the monomer and the uniformity of the reaction. In addition, their specific surface area is limited, resulting in restricted diffusion of the photoinitiator and the monomer inside the MOF, reducing the storage efficiency. Summary of the Invention

[0004] The purpose of the present invention is to provide a mesoporous MOF optical storage material, a preparation method thereof, and an application thereof, so as to solve the technical problem of poor optical storage effect of the existing materials.

[0005] To achieve the above purpose, the present invention adopts the following technical solutions:

[0006] The present invention discloses a preparation method of a mesoporous MOF optical storage material, including the following steps:

[0007] Dissolve a metal salt, ZrOCl₂·8H₂O and an organic ligand in a solvent, and then add a carboxylic acid compound to the solvent to obtain a reaction solution;

[0008] Carry out a heating reaction on the reaction solution. After the reaction is completed, post-treat the obtained reaction product to obtain a mesoporous MOF optical storage material;

[0009] The organic ligand is 2,6-dimethyl-4-pyridin-4-ylbenzoic acid, 2',5'-dimethyl-4'-(pyridin-4-yl)-1,1'-biphenyl-4-ylbenzoic acid or isonicotinic acid.

[0010] Further, the metal ion in the metal salt is Ni 2+ , Co 2+ , Cu 2+ , Rh 2+ and Pd 2+ and is one of them.

[0011] Further, the dosage ratio of the metal salt, ZrOCl₂·8H₂O, the organic ligand and the solvent is (7.5 - 18) mg : (4.5 - 10) mg : (13 - 30) mg : 1 mL.

[0012] Further, the carboxylic acid compound is trifluoroacetic acid or benzoic acid;

[0013] When it is trifluoroacetic acid, the volume ratio of the trifluoroacetic acid to the solvent is 30 μL : 1 mL;

[0014] When it is benzoic acid, the dosage ratio of the benzoic acid to the solvent is 20 mg : 1 mL.

[0015] Further, the metal salt is one of nickel nitrate hexahydrate, copper nitrate hexahydrate, palladium nitrate, rhodium nitrate dihydrate, cobalt nitrate hexahydrate and nickel nitrate hexahydrate.

[0016] Further, the heating reaction is carried out in an oven; the temperature in the oven is (80 - 100) °C, and the heating reaction time is 24 - 48 h.

[0017] The present invention also discloses a mesoporous MOF optical storage material prepared by the above preparation method, and the pore diameter of the mesoporous MOF optical storage material is 2 - 4 nm.

[0018] The present invention also discloses the application of the above mesoporous MOF optical storage material in optical information storage, including the following steps:

[0019] Load a photoinitiator and a monomer inside the pore channels of the mesoporous MOF optical storage material to obtain a two-photon polymerization optical storage material of the mesoporous MOF;

[0020] Subsequently, a storage pattern is formed inside the two-photon polymerization optical storage material of the mesoporous MOF through two-photon polymerization reaction to achieve optical information storage.

[0021] Furthermore, it is characterized in that the method for loading the photoinitiator and the monomer is solvent exchange or impregnation method; the molecules of the photoinitiator and the monomer can enter the pores of the mesoporous MOF optical storage material.

[0022] Furthermore, it is characterized in that the two-photon polymerization reaction is realized by femtosecond laser processing inside the single crystal of the mesoporous MOF optical storage material.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention discloses a preparation method of a mesoporous MOF optical storage material, which uses metal salts, ZrOCl2·8H2O, and carboxylic acid compound solvents as raw materials. By setting different organic ligands, the pore size can be gradually increased by adjusting the structure of the organic ligands to achieve a controllable optical information storage system. At the same time, compared with the microporous MOF-5 and D-MOF of the present invention, the MOF system can not only optimize the loading amounts of the monomer and the photoinitiator, but also load more types of photoinitiators and monomers, thereby enhancing its applicability and functional diversity. Moreover, while expanding the pore size, the present invention can still maintain its inherent high specific surface area and good pore distribution, which not only improves the diffusion efficiency of the monomer and the photoinitiator inside the MOF, but also enhances the uniform distribution of the photoinitiator, thereby ensuring the uniformity of the photopolymerization reaction, improving the reliability and stability of information storage. The larger pore size further enhances the tunability of the monomer and the photoinitiator, so that the storage parameters can be optimized according to different application requirements to achieve higher storage efficiency and longer storage life, and solve the technical problem of poor optical storage effect of the existing materials.

[0025] The present invention also discloses the application of the mesoporous MOF optical storage material prepared by the above preparation method in optical information storage. Since the pore size of the present invention can be regulated by the organic ligand, the information storage density per unit volume can be increased, enabling more data to be stored in the same volume, and the storage density is higher than that of the prior art; the larger pore volume and regular pore structure enable the photoinitiator and monomer to be evenly distributed, ensuring the accuracy and repeatability of the stored information and reducing the error during data reading, and the loading is more uniform than that of the prior art; the loading system of the present invention has a larger pore diameter and a regulable structure, and can load various different types of photoinitiators to adapt to different optical storage requirements, improving the versatility and adaptability of the material; in addition, by laser processing, two-photon polymerization reaction is realized inside the crystal to construct a nanoscale storage pattern, achieving sub-micron-scale optical information storage, breaking through the resolution limit of traditional single-photon storage, and improving the storage density and information accuracy.

[0026] Furthermore, by precisely regulating the optical storage position with femtosecond laser, an information storage lattice can be formed in three-dimensional space to achieve ultra-high density information storage, far exceeding the storage capacity of existing optical storage materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is the crystal optical image of Ni-MOF-626 of the present invention;

[0028] Figure 2 is the crystal structure characterization diagram of Ni-MOF-626 of the present invention;

[0029] wherein: a - crystal structure; b - XRD pattern; c - FT-IR spectrum;

[0030] Figure 3 is the SEM image and EDS mapping image of Ni-MOF-626 of the present invention;

[0031] wherein: a - SEM image; b - EDS mapping image of C; c - EDS mapping image of N; d - EDS mapping image of O; e - EDS mapping image of Ni; f - EDS mapping image of Zr;

[0032] Figure 4 is the AFM image of Ni-MOF-626 of the present invention;

[0033] Figure 5 is the performance test result of Ni-MOF-626 of the present invention;

[0034] Wherein: a - Nitrogen adsorption isotherm (77K); b - Pore size distribution curve; c - BET specific surface area (estimated between the dotted lines); d - Linear fitting result of BET specific surface area;

[0035] Figure 6 are the chemical structure diagrams of photoinitiator and monomer;

[0036] Figure 7 are the performance test results of Ni-MOF-626-DETC-PEGDA of the present invention;

[0037] Wherein: a - Nitrogen adsorption isotherm (77K); b - Pore size distribution curve; c - BET specific surface area (estimated between the dotted lines); d - Linear fitting result of BET specific surface area;

[0038] Figure 8 is the XRD pattern of Ni-MOF-626-DETC-PEGDA of the present invention;

[0039] Figure 9 is the IR spectrum of Ni-MOF-626-DETC-PEGDA of the present invention;

[0040] Figure 10 are the SEM image and EDS mapping images of Ni-MOF-626-DETC-PEGDA of the present invention;

[0041] Wherein: a - SEM image; b - EDS mapping image of C; c - EDS mapping image of N; d - EDS mapping image of O; e - EDS mapping image of Ni; f - EDS mapping image of Zr; g - EDS mapping image of S;

[0042] Figure 11 is the storage of three-dimensional regular hexagonal pattern of MOF-626 single crystal;

[0043] Figure 12 is the storage of three-dimensional lattice pattern of MOF-626 single crystal;

[0044] Figure 13 is the storage of three-dimensional logo pattern of MOF-626 single crystal. Detailed implementation manners

[0045] To enable those skilled in the art to understand the features and effects of the present invention, the following provides a general description and definition of the terms and phrases mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used herein shall have the ordinary meaning understood by those skilled in the art for the present invention. In case of conflict, the definition in this specification shall prevail.

[0046] The theories or mechanisms described and disclosed herein, whether right or wrong, shall not limit the scope of the present invention in any way, that is, the content of the present invention can be implemented without being limited by any specific theory or mechanism.

[0047] In this article, all features defined in the form of numerical ranges or percentage ranges, such as numerical values, quantities, contents, and concentrations, are only for the sake of brevity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be regarded as having covered and specifically disclosed all possible sub-ranges and individual numerical values within the range (including integers and fractions).

[0048] In this article, unless otherwise specified, the terms "comprising", "including", "containing", "having", or similar terms cover the meanings of "consisting of" and "consisting essentially of". For example, "A comprises a" covers the meanings of "A comprises a and others" and "A consists only of a".

[0049] In this article, for the sake of brevity of description, all possible combinations of all technical features in each embodiment or example are not described. Therefore, as long as there is no contradiction in the combination of these technical features, the technical features in each embodiment or example can be combined arbitrarily, and all possible combinations should be considered to be within the scope described in this specification.

[0050] The present invention provides a preparation method of a mesoporous MOF optical storage material. Using MOF as the carrier for optical information storage, by loading a photoinitiator and a monomer into the pores of the MOF, a spatially confined polymerization reaction occurs when irradiated by laser, thereby realizing information storage. This method is different from the traditional organic dye storage method. It uses the regular pore structure of MOF to provide stable physical isolation, avoiding the diffusion problem of the photoinitiator and the monomer, thereby improving the stability of information storage. In addition, the MOF carrier can optimize the loading amount and reaction uniformity of the storage material by adjusting the pore size, making the stored information have higher controllability and reusability.

[0051] The present invention is based on microporous MOF-616, mesoporous MOF-626, and MOF-636. By adjusting the structure of the organic ligand, the pore size is gradually increased to realize a controllable optical information storage system. Compared with microporous MOF-5 and D-MOF, the MOF system of the present invention can not only optimize the loading amount of the monomer and the photoinitiator, but also load more types of photoinitiators and monomers than MOF-5 and DMOF, thereby enhancing its applicability and functional diversity.

[0052] In addition, while expanding the pore size, MOF-616, MOF-626, and MOF-636 can still maintain their inherent high specific surface area and good pore distribution. This property not only improves the diffusion efficiency of monomers and photoinitiators inside the MOF but also enhances the uniform distribution of photoinitiators, thereby ensuring the uniformity of the photopolymerization reaction and improving the reliability of information storage. The larger pore size further enhances the tunability of monomers and photoinitiators, enabling the optimization of storage parameters according to different application requirements and achieving higher storage efficiency and longer storage life.

[0053] The method of the present invention includes the following steps:

[0054] Synthesis and preparation of MOF materials: MOF-616, MOF-626, and MOF-636 are prepared by a controllable synthesis method, loaded with metal ions, the pore structure is optimized, and detailed physicochemical characterization is carried out to ensure that the MOF has good stability and loading capacity; since metal ions can be selected from Ni 2+ , Co 2+ , Cu 2+ , Rh 2+ and Pd 2+ , and relevant literature has verified that Ni is mainly selected in the present invention 2+ as the metal ion, and Ni-MOF-626 is taken as an example for illustration.

[0055] Loading of photoinitiator and monomer: The photoinitiator and monomer are precisely loaded into the pores of the MOF by methods such as solvent exchange and impregnation to ensure the uniform distribution of the material, and the loaded MOF material is obtained.

[0056] Laser-induced two-photon polymerization: The loaded MOF material is spatially selectively exposed using femtosecond laser, and precise polymer patterns are formed inside the MOF through two-photon polymerization reaction to achieve high-precision optical information storage.

[0057] Information reading: Information is read using a fluorescence microscope, optical microscope, or CCD camera.

[0058] Optimization and application of stored information: For different application requirements, the pore size, loading amount, and photopolymerization parameters of the MOF are adjusted to optimize the storage density and stability, making it applicable to fields such as high-density data storage, security encryption, and information anti-counterfeiting.

[0059] Compared with traditional optical storage materials (such as polymer matrices, organic dyes, or inorganic semiconductors), the MOF-6X6 (MOF-616, MOF-626, MOF-636) system has higher loading stability. In traditional optical storage materials, photoinitiators and monomers are usually distributed in the matrix by physical doping and are vulnerable to environmental factors (such as temperature, humidity, light, etc.), which can lead to diffusion, degradation, or photobleaching, resulting in poor long-term stability of the stored information. In contrast, the MOF-6X6 structure has highly regular pores and immobilizes photoinitiators and monomers through the molecular confinement effect, effectively inhibiting their diffusion and degradation and improving the long-term reliability of information storage. In addition, the high specific surface area and stable framework structure of the MOF-6X6 structure can ensure that the optically stored information remains clear for a long time, making it suitable for long-term data storage and anti-counterfeiting applications.

[0060] Compared with the MOF-5 system, MOF-6X6 has significant advantages in terms of information storage density, loading uniformity, and the types of photoinitiators that can be accommodated:

[0061] Higher storage density: Due to the relatively small pore size of MOF-5, the unit density of stored information is limited, and it is difficult to further improve the data storage capacity due to the influence of the light diffraction limit. In contrast, the MOF-6X6 system can increase the information storage density per unit volume through adjustable pore sizes (2 - 4 nm), enabling it to store more data in the same volume.

[0062] More uniform loading: Due to its small pore size and relatively limited specific surface area, MOF-5 often exhibits uneven distribution and easy agglomeration of photoinitiators and monomers, which affects the uniformity and readability of optically stored data. In contrast, MOF-6X6 has a larger pore volume and a regular pore structure, enabling photoinitiators and monomers to be evenly distributed, ensuring the accuracy and repeatability of stored information, and reducing errors during data reading.

[0063] A wider variety of photoinitiators can be loaded: Due to its relatively small pore size, MOF-5 has a limited range of choices for photoinitiators and monomers and is only suitable for a small number of small molecule initiators. In contrast, the MOF-6X6 system has a larger pore size and a tunable structure, enabling it to load a variety of different types of photoinitiators (such as DETC, BAPO, TPO, etc.), adapting to different optical storage requirements and improving the versatility and adaptability of the material.

[0064] The following further elaborates on the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0065] Conventional instruments and equipment in the art are used in the following examples. For the experimental methods without specific conditions noted in the following examples, they are generally carried out under conventional conditions or according to the conditions recommended by the manufacturer. Various raw materials are used in the following examples. Unless otherwise specified, commercially available products are used, and their specifications are the conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" represents weight percentage, "parts" represents weight parts, and the ratio represents weight ratio.

[0066] In the method of the present invention, first, the organic ligands PBA (2,6-dimethyl-4-pyridin-4-ylbenzoic acid) and PBCA (2',5'-dimethyl-4'-(pyridin-4-yl)-1,1'-biphenyl-4-ylbenzoic acid) required for synthesizing MOF are synthesized, and Ni-MOF-616, Ni-MOF-626, and Ni-MOF-636 crystals are synthesized therefrom; subsequently, Ni-MOF-626 is characterized to verify its stability; then, a photoinitiator and a monomer are loaded into Ni-MOF-626 to evaluate its loading capacity and stability; finally, information storage is achieved on the crystal, and its polymerization performance is verified through a three-dimensional graph and a dot matrix structure.

[0067] The preparation method of the organic ligand PBA adopted in the present invention is as follows:

[0068] 4-Bromo-2,6-dimethylbenzoic acid (3.7 g, 0.016 mol), 4-pyridylboronic acid (4.0 g, 0.033 mol), sodium carbonate (5.1 g, 0.048 mol), and tetrakis(triphenylphosphine)palladium(0) (0.93 g, 0.8 mmol) are dissolved in a mixed solution of DME and water (1:1, v / v, 200 mL); the reaction mixture is refluxed at 95 °C for 24 hours with continuous stirring; after the reaction is completed, the hot suspension is filtered to remove insoluble substances, the filtrate is concentrated to about 100 mL, and the aqueous phase is washed with dichloromethane; subsequently, the aqueous phase is acidified to pH 5 with 2 M hydrochloric acid, the obtained white precipitate is collected by filtration and washed thoroughly with water, and finally the purified product PBA (2.4 g, 11 mmol) is obtained with a yield of 66%; the obtained product is dried and then characterized for purity. The reaction process is shown by the following reaction formula:

[0069]

[0070] The preparation method of the organic ligand PBCA adopted in the present invention is as follows:

[0071] It is synthesized through the Suzuki - Miyaura coupling reaction. First, an intermediate compound 1 is produced by reacting 1,4 - dibromo - 2,5 - dimethylbenzene with 4 - carboxyphenylboronic acid. Then, 4 - pyridylboronic acid reacts with compound 1 to obtain compound 2. Compound 2 is hydrolyzed under alkaline conditions, followed by acidification and precipitation to finally obtain pure - phase PBCA.

[0072] 1) Synthesis of compound 1: Dissolve 1,4 - dibromo - 2,5 - dimethylbenzene (100 g, 379 mmol) and 4 - carboxyphenylboronic acid (21.6 g, 120 mmol) in a mixed solution of 1,4 - dioxane / water (4:1, v / v, 600 mL). Under an argon atmosphere, add potassium carbonate (41.6 g, 301 mmol) and (1,1'-bis(diphenylphosphino)ferrocene)palladium(II) dichloride (4.4 g, 5.9 mmol), and stir the reaction at 85 °C for 4 hours. After the reaction is completed, cool the mixture to room temperature, extract it three times with ethyl acetate, and wash it three times with deionized water. Dry the organic phase with anhydrous sodium sulfate for half an hour, filter, and then evaporate the solvent. The obtained crude product is subjected to column chromatography using petroleum ether / ethyl acetate as the eluent in a ratio of 10:1 to further obtain the pure product with a yield of 75% (28.71 g, 90 mmol).

[0073] 2) Synthesis of compound 2: Dissolve compound 1 (3.2 g, 10 mmol), 4 - pyridylboronic acid (1.8 g, 15 mmol), potassium carbonate (4.1 g, 30 mmol), and tetrakis(triphenylphosphine)palladium(0) (500 mg, 0.5 mmol) in a mixed solution of 1,2 - dioxane / water (4:1, v / v, 100 mL). Under an argon atmosphere, reflux and stir the reaction at 95 °C for 24 hours. After the reaction is completed, filter off the insoluble matter while it is hot, and extract the filtrate with dichloromethane. Dry the organic phase with anhydrous sodium sulfate for half an hour, filter, and then evaporate the solvent. The obtained crude product is subjected to column chromatography using petroleum ether / ethyl acetate as the eluent in a ratio of 10:1 to further obtain the pure product, compound 2.

[0074] 3) Synthesis of PBCA: Dissolve compound 2 (2 g, 6.3 mmol) in a KOH solution of THF / MeOH / H2O (v:v:v = 2:2:1) and reflux at 95 °C for 24 hours. After the reaction is completed, evaporate THF and methanol, add water to the remaining suspension and heat to dissolve. The obtained aqueous phase is filtered, acidified to pH 5 with 2 M hydrochloric acid, and the resulting white precipitate is collected by filtration and washed thoroughly with water. Finally, purified PBCA (1.5 g, 11 mmol) is obtained with a yield of 79%. The reaction process is shown by the following reaction formula:

[0075]

[0076] Example 1

[0077] A preparation method of a mesoporous MOF optical storage material, comprising the following steps:

[0078] Dissolve Ni(NO3)2·6H2O (18 mg, 0.062 mmol), ZrOCl2·8H2O (9 mg, 0.028 mmol) and INA isonicotinic acid (13 mg, 0.106 mmol) in 1 mL of DMF solvent. Subsequently, add 30 μL of trifluoroacetic acid to the solvent and ultrasonically vibrate for 5 minutes until the sample dissolves. Set the oven to 100 °C, place the reaction solution therein, react for 48 hours, and after cooling to room temperature, a light green cubic phase crystal can be obtained. Replace the reaction solvent with fresh DMF to remove the unreacted organic ligands and metal salts, replace once every 8 hours, repeat 5 times and set aside to obtain the mesoporous MOF optical storage material, denoted as Ni-MOF-616.

[0079] Example 2

[0080] A preparation method of a mesoporous MOF optical storage material, comprising the following steps:

[0081] Dissolve Ni(NO3)2·6H2O (7.5 mg, 0.026 mmol), ZrOCl2·8H2O (4.5 mg, 0.014 mmol) and PBA (14 mg, 0.062 mmol) in 1 mL of DMF solvent. Subsequently, add 15 μL of trifluoroacetic acid to the solvent and ultrasonically vibrate for 5 minutes until the sample dissolves. Set the oven to 100 °C, place the reaction solution therein, react for 48 hours, and after cooling to room temperature, a light blue cubic phase crystal (as Figure 1 shown) can be obtained. Replace the reaction solvent with fresh DMF to remove the unreacted organic ligands and metal salts, replace once every 8 hours, repeat 5 times and set aside to obtain the mesoporous MOF optical storage material, denoted as Ni-MOF-626.

[0082] Example 3

[0083] A preparation method of a mesoporous MOF optical storage material, comprising the following steps:

[0084] Dissolve Ni(NO3)2·6H2O (15 mg, 0.052 mmol), ZrOCl2·8H2O (10 mg, 0.031 mmol) and PBA (30 mg, 0.099 mmol) in 1 mL of DMF solvent. Subsequently, add 20 mg of benzoic acid to the solvent and ultrasonically agitate for 5 minutes until the sample is dissolved. Set the oven to 80 °C, place the reaction solution in it, react for 24 hours, and after cooling to room temperature, dark blue cubic phase crystals can be obtained. Replace the reaction solvent with fresh DMF to remove the unreacted organic ligands and metal salts, replacing once every 8 hours and repeating 5 times for standby, to obtain a mesoporous MOF optical storage material, denoted as Ni-MOF-636.

[0085] Perform crystal characterization on the Ni-MOF-626 prepared in Example 2:

[0086] 1) Crystal structure and chemical bonding analysis: Confirm the structural purity of the organic ligand through nuclear magnetic resonance spectroscopy ( 1 H NMR and 13 C NMR); Use X-ray diffraction (XRD) to analyze the crystallinity and crystal structure of the MOF to ensure its consistency with the theoretical model; Fourier transform infrared spectroscopy (FT-IR) detects the chemical bonding between the organic ligand and the metal node to verify the stability of the framework structure. The results obtained are as Figure 2 shown. By performing structural characterization of Ni-MOF-626 through XRD, it can be clearly seen that the positions of the diffraction peaks highly match the theoretical simulation data, indicating that Ni-MOF-626 was successfully assembled into a three-dimensional framework structure with high crystallinity during the synthesis process, and the periodic ordered arrangement of the crystals was effectively verified. Specifically, Ni-MOF-626 before activation exhibited a series of strong and sharp diffraction peaks, indicating excellent crystallization quality of the material. After activation, although the guest molecules within the framework of Ni-MOF-626 were removed, its diffraction peaks remained stable without significant intensity attenuation or peak position drift. This fully demonstrates that Ni-MOF-626 has excellent framework stability and can maintain its structural integrity after removing the template molecules, providing a stable carrier for subsequent doping molecules and two-photon polymerization reactions.

[0087] FT-IR further verified the chemical bonding of Ni-MOF-626. Comparing the spectra of the PBA precursor and Ni-MOF-626, it can be found that: in the spectrum of PBA, the characteristic stretching vibration peak of the carboxyl group (C=O) is located at 1708 cm -1 , while in the spectrum of Ni-MOF-626, this peak is significantly red-shifted to 1659 cm -1, indicating that the carboxyl groups in PBA are combined with the metal Zr nodes through coordination bonds to form a stable framework structure; the stretching vibration characteristic peak of the pyridyl group (C=N) in PBA is located at 1606 cm -1 , in the spectrum of Ni-MOF-626, this characteristic peak is slightly shifted to 1595 cm -1 . This change further proves that the pyridyl group has successfully coordinated with the metal node Ni. In addition, there are multiple vibration peaks in the range of 500 - 1000 cm -1 , indicating that Ni-MOF-626 has a stable and highly ordered coordination structure. The FT-IR spectrum and the XRD results confirm each other, indicating that the material has been successfully constructed into Ni-MOF-626 and exhibits high structural stability and chemical integrity.

[0088] 2) Crystal morphology and surface microstructure analysis: Scanning electron microscopy (SEM) and atomic force microscopy (AFM) are used to observe the morphological characteristics and surface microstructure of the MOF, and to evaluate the uniformity and surface quality of the crystals; energy-dispersive X-ray spectroscopy (EDS) is used for elemental mapping to verify the uniform distribution of each element in the crystal, and the results are as shown in Figure 3 and Figure 4 . It can be seen from the SEM image of the Ni-MOF-626 crystal that Ni-MOF-626 crystallizes in a regular cubic morphology, the crystal size reaches about 300 μm, the surface is flat and smooth, and the edge lines are clear and sharp, indicating that the material has achieved a highly controllable nucleation and growth process during growth, and no obvious crystal aggregation, cracks or defects have occurred. It should be noted that the cubic structure of the crystal provides sufficient physical space and ideal pore distribution for subsequent molecular doping, which can promote the uniform distribution of guest molecules within the framework and provide sufficient reaction interfaces at the same time.

[0089] To further confirm the elemental composition and its spatial distribution of Ni-MOF-626, energy-dispersive X-ray spectroscopy (EDS) is used for elemental mapping. It can be seen from the figure that the elements C, N, O, Ni and Zr are uniformly distributed throughout the crystal, and no element enrichment, segregation or deficiency is observed. This indicates that a highly uniform combination of metal nodes and ligands has been achieved during the synthesis of the material, and at the same time, the structural integrity and elemental distribution uniformity of the framework have been strongly verified; among them, the C and N elements are from the organic part of the ligand, the Ni element comes from the central node of the framework, the Zr element comes from the metal-oxygen cluster unit, and the O element is distributed throughout the coordination structure. This structurally uniform characteristic provides an ideal carrier platform for subsequent doping of photosensitive molecules and monomers, which helps to achieve molecular-level uniform distribution and effective reaction within the framework pores.

[0090] To further reveal the surface microtopography and structural uniformity of Ni-MOF-626 crystals, AFM was used to characterize them. From the two-dimensional height distribution map, it can be seen that the surface of the Ni-MOF-626 crystal is relatively flat as a whole. The microscopic height fluctuations are distributed in the range of -3.920 nm to 3.340 nm, and there are no obvious pits or protrusion structures, indicating that the surface quality of the material is high and the crystal growth process is well controlled. In addition, the three-dimensional surface topography map further intuitively shows the height uniformity and microscopic fluctuation characteristics of the crystal surface. The surface roughness is low and the fluctuation changes are gentle, reflecting that the material has a nanoscale high degree of consistency. Quantitative analysis shows that the average roughness of the crystal surface (Ra = 0.459) is small, indicating that Ni-MOF-626 has achieved highly regular growth during the synthesis process, with a uniform surface topography and few defects. This result is highly consistent with the smooth surface and sharp edges observed in the SEM characterization, further verifying the high crystallinity and surface integrity of the material.

[0091] 3) Pore structure analysis and specific surface area characterization: The pore size distribution and specific surface area of the MOF were determined by nitrogen adsorption-desorption experiments to evaluate its ability as an efficient molecular carrier. The results are as Figure 5 shown. It can be seen from the figure that the isotherm of Ni-MOF-626 exhibits typical type I isotherm characteristics, which conforms to the classification standard of microporous materials by IUPAC, and at the same time shows certain sub-mesoporous characteristics; in the low relative pressure region (P / P0 < 0.1), the nitrogen adsorption amount increases rapidly, and the maximum adsorption rate appears in the extremely low pressure region, indicating that the micropores in the material can quickly fill nitrogen molecules; as the relative pressure increases, the adsorption amount gradually stabilizes and reaches a saturated state in the high pressure region (P / P0 ∼ 1), and the maximum nitrogen adsorption amount is 650 cm 3 ·g-1 STP. In addition, the adsorption and desorption curves almost coincide, and no obvious hysteresis loop appears, indicating that the pore structure of Ni-MOF-626 is highly uniform and open, and there is no significant pore blockage or retention phenomenon.

[0092] The DFT model was used to analyze the pore size distribution of the desorption data. It can be seen from the pore size distribution curve that the pore size of Ni-MOF-626 is mainly distributed in the range, with a peak value of about and the distribution is relatively concentrated. This result indicates that the material has a highly uniform microporous and sub-mesoporous structure, the size and distribution are well controlled, and no obvious pore size dispersion phenomenon appears. In addition, by fitting and calculating the nitrogen adsorption isotherm data by the BET method, the specific surface area of Ni-MOF-626 was obtained as 2361 m 2· g-1. This relatively high specific surface area is attributed to the highly ordered microporous structure and good porosity of the material, which can provide a large number of surface active sites. At the same time, a small amount of sub-mesopores contribute to the rapid diffusion and filling of molecules, demonstrating the potential advantages of the material in adsorption. The linear correlation of BET fitting is good, and the correlation coefficient is close to 1, further verifying the accuracy and reliability of the specific surface area calculation results.

[0093] Application Example 1

[0094] S1: Load the photoinitiator and monomer inside the pores of the mesoporous MOF obtained in Example 2 to obtain a two-photon polymerization optical storage material (Ni-MOF-626-DETC-PEGDA) of mesoporous MOF; among them, the photoinitiator and monomer are PEGDA and DETC respectively. Of course, appropriate MOF matrix, photoinitiator and monomer can also be selected according to the pore size.

[0095] S2: Subsequently, form a storage pattern inside the two-photon polymerization optical storage material of mesoporous MOF through two-photon polymerization reaction to achieve optical information storage.

[0096] Among them, the theoretical calculation of the photoinitiator is to verify its entry into Ni-MOF-626 through theoretical calculation of the molecular size of the photoinitiator; the size of the photoinitiator DETC molecule is The pore size of Ni-MOF-626 is about 2 nm. Therefore, the photoinitiator can theoretically enter the pores, as Figure 6 shown. It can be seen from the figure that the sizes of the three photoinitiator molecules are similar in the length, width and height directions, and the specific range is the length width and height all within the range allowed by the pore size of MOF-626 The overall molecular structure is flat or compactly distributed, and the maximum size is close to but does not exceed the upper limit of the pore. This indicates that they can smoothly enter the interior of the pores; from the perspective of spatial adaptability, the height and width of the molecules are much smaller than the pore diameter, providing sufficient space margin, which is beneficial to the stable loading and diffusion of molecules in the pores. In addition, the flat-structured photoinitiator molecules DEPC and DETC can further reduce the space occupation by adjusting the orientation during the adaptation process, enhancing the uniformity of loading; while the 4-DI-2-ASP molecule is slightly more compact, but its size is still within a reasonable range, and the exclusion effect is small; all three photoinitiator molecules show good adaptability and can effectively match the pores of MOF-626.

[0097] In S2, the loading method is as follows: Weigh DETC (14.02 mg, 0.04 mmol) and dissolve it in 2 mL of DMF. Then add 1 mL of PEGDA(200), and ultrasonically oscillate for 2 minutes until completely dissolved. Place the MOF-626 crystals into the solution and let it stand in an oven at 40 °C for 24 hours. After cooling to room temperature, the sample is stored in the mother liquor for later use. The pore size distribution and specific surface area of the loaded MOF are measured by nitrogen adsorption-desorption experiments. As Figure 7 shown, it can be seen from the nitrogen adsorption-desorption isotherm that after doping with DETC, the isotherm of Ni-MOF-626 still exhibits typical type I isotherm characteristics, which conforms to the classification standard of microporous materials by IUPAC, and retains certain sub-mesoporous characteristics. In the low relative pressure region (P / P0 < 0.1), the adsorption amount of nitrogen increases rapidly, and the maximum adsorption rate appears in the extremely low pressure region, indicating that the micropores in the material can still rapidly fill nitrogen molecules. As the relative pressure increases, the adsorption amount gradually stabilizes and reaches a saturated state in the high pressure region (P / P0 ∼ 1). The maximum nitrogen adsorption amount is 400 cm 3 ·g -1 STP, slightly lower than that of the undoped sample (650 cm 3 ·g-1STP). This change may be due to the fact that DETC molecules occupy some of the micropore space, reducing the adsorption capacity of the effective pore channels.

[0098] The pore size distribution analysis of the desorption data is carried out using the DFT model. The pore size distribution curve shows that after doping with DETC, the pore sizes are mainly concentrated in the range of 1.5 - 2.5 nm, and the peak shifts slightly towards the smaller pore direction, concentrating around about 2.0 nm. This indicates that the introduction of DETC molecules partially occupies the pore space, resulting in a slight decrease in the effective pore size, but the overall distribution is still relatively uniform, and no significant pore size dispersion phenomenon occurs. In addition, by fitting and calculating the nitrogen adsorption isotherm data using the BET method, the specific surface area of Ni-MOF-626 after doping with DETC is 1505 m 2 ·g-1, significantly lower than that of the undoped sample, which is 2361 m 2 ·g-1. This change further verifies that DETC molecules occupy some of the internal pore space, reducing the available surface area. However, the specific surface area after doping is still relatively high, indicating that the microporous framework structure of the material remains good during the doping process, without structural collapse or serious damage. The BET fitting shows good linear correlation, and the correlation coefficient is close to 1, further verifying the reliability of the specific surface area calculation results; By comparing the results of the nitrogen adsorption-desorption experiments before loading, the loading amount can be adjusted by adjusting the amounts of PEGDA and DETC. The results show that the current loading amount is about 33%.

[0099] After loading, X-ray diffraction (XRD) was used to analyze the crystallinity and crystal structure of the MOF to ensure its consistency with the theoretical model. The results are as Figure 8 shown. It can be seen from the figure that the diffraction peak positions of Ni-MOF-626-DETC are the same as those of the original Ni-MOF-626, indicating that the loading of the photoinitiator did not change the periodicity and order of the crystal framework. No significant shift or disappearance of the peaks was observed, further verifying the integrity of the framework structure. By comparing the simulation results and the experimental results, it can be found that the crystal diffraction peaks after loading DETC still match the theoretical calculations, indicating that the loading process did not cause the framework structure to collapse or reorganize. In addition, no new diffraction peaks appeared in the XRD pattern, indicating that the loading of DETC molecules did not introduce any new phases or crystalline impurities. At the same time, the width and shape of the diffraction peaks remained basically the same, indicating that the crystallinity of the crystal was not significantly affected, which shows that DETC molecules have good adaptability to the physical and chemical environment of the MOF framework during the loading process.

[0100] Fourier transform infrared spectroscopy (FT-IR) was used to detect the chemical bonding between the organic ligand and the metal node. The results are as Figure 9 shown. It can be seen from the figure that from the spectrum of DETC itself, the C=O stretching vibration peak is located at 1714 cm -1 . This is a characteristic vibration unique to DETC molecules. After doping Ni-MOF-626, the carboxyl peak of DETC showed an obvious red shift to 1722 cm -1 . This change indicates that the carboxyl group of DETC molecules binds to the inner wall or surface environment of the MOF framework pores through weak interactions (such as hydrogen bonds or electrostatic interactions). This weak interaction not only promotes the stable embedding of DETC molecules but also reflects the distribution characteristics of DETC in the framework pores. In the spectrum of Ni-MOF-626 before doping, the characteristic peak of the asymmetric stretching vibration of C=O was located at 1659 cm -1 . After doping DETC, this characteristic peak blue-shifted to 1675 cm -1 , indicating that the introduction of DETC molecules had a significant impact on the electron distribution in the pore microenvironment. This blue-shift phenomenon is attributed to the coupling of the carboxyl group of DETC molecules with the local metal coordination sites or surface adsorption sites of the Ni-MOF-626 framework. Although the peak position of the carboxyl group changed, the peak shape remained clear and sharp, indicating that the carboxyl characteristics of the framework and the pore environment were not damaged. In addition, the characteristic peak of the C=N stretching vibration of the pyridyl group in the framework remained at 1595 cm -1 before and after doping, without obvious displacement or peak shape change. This result further confirmed that the core coordination structure of the framework was not damaged during the doping process, indicating that the chemical and mechanical stability of the framework remained excellent.

[0101] The morphology and surface microstructure of the MOF were observed by scanning electron microscopy (SEM) to evaluate the uniformity and surface quality of the crystals. The results are as Figure 10 shown. From the figure, the SEM image of the loaded Ni-MOF-626 crystals can be seen, showing that the crystals still maintain a regular cubic morphology after loading the photoinitiator, the crystal size has not changed significantly, the surface is still flat and smooth, and the edge lines are clear and sharp. This indicates that the MOF framework structure has good stability and structural integrity during the loading process of the photoinitiator molecules, and there are no obvious crystal cracks, surface roughening or other significant morphological changes, further indicating its strong tolerance to the loading process.

[0102] To further confirm the elemental composition and its spatial distribution after loading the photoinitiator molecules, elemental mapping analysis was carried out using EDS. It can be clearly seen from the figure that the elements C, N, O, Ni, and Zr still maintain a uniform distribution in the loaded crystals. At the same time, the characteristic element S in the newly introduced photoinitiator molecules is also uniformly distributed throughout the crystals. This uniform spatial distribution characteristic indicates that the photoinitiator molecules have successfully entered the ordered pores of Ni-MOF-626 and achieved a molecular-level uniform distribution in the framework structure, and no element enrichment, segregation or local deficiency phenomena were observed. Specifically, the C and N elements mainly come from the organic part of the ligand, the Ni element is the core component of the metal node, the Zr element comes from the metal-oxygen cluster unit, and the O element runs through the entire coordination network structure. The introduction of the S element clearly indicates the successful loading of the photoinitiator, and its uniform distribution characteristic further proves the high efficiency of Ni-MOF-626 in molecular diffusion and adsorption during the loading process. This uniformity after loading and the stability of the framework not only verify the high loading capacity of the material during the molecular loading process, but also provide a stable and ideal reaction environment for the subsequent two-photon polymerization reaction. Such results show that Ni-MOF-626 can not only maintain structural integrity during the photoinitiator loading process, but also effectively guide the diffusion and uniform distribution of guest molecules through the uniform pore distribution, laying a foundation for achieving high-efficiency optical performance and subsequent high-density information storage applications.

[0103] In S2, to preliminarily explore the storage capacity of Ni-MOF-626 single crystals, a regular regular hexagon was selected as the storage pattern, and laser processing was carried out inside the Ni-MOF-626 single crystal by precisely controlling the laser parameters. The unprocessed MOF-626 single crystal showed a highly transparent and uniform appearance, with a complete internal structure and no obvious defects, indicating that the material has good optical homogeneity and a highly ordered crystal structure. After femtosecond laser processing, a clearly visible regular hexagon pattern was successfully formed inside the single crystal, as Figure 11As shown, it can be seen from the figure that the pattern has sharp boundaries and regular morphology, indicating that the femtosecond laser energy can accurately act on the MOF-626 crystal under controlled conditions to achieve local polymerization without damaging the integrity of the overall structure. The experimental results show that within a reasonable range of processing parameters, MOF-626 can carry high-precision laser-stored information without causing significant material damage or structural degradation, demonstrating its feasibility in high-density optical storage.

[0104] To further explore the optical storage ability of MOF-626 single crystals, the experiment used the same laser processing parameters to construct a high-density dot pattern inside the single crystal, as Figure 12 shown. It can be seen that through optimizing the control of the laser focus, a regularly arranged dot structure has been successfully formed inside the MOF-626 single crystal. The pattern boundaries are clear and the arrangement is uniform, indicating that femtosecond lasers can achieve precise information storage inside this material. In addition, this storage mode exhibits good stability without introducing obvious material damage or thermal effects during the processing. This experimental result further shows that MOF-626 single crystals have good applicability in high-density information storage applications.

[0105] To further verify the application potential of MOF-626 in the field of information storage and evaluate its adaptability in complex pattern storage, the experiment used the same laser processing parameters to process the logo of the Laser Manufacturing Institute of Henan Academy of Sciences inside the MOF-626 single crystal, as Figure 13 shown. The experimental results show that the pattern is clearly visible, the boundary is complete, and there are no obvious scattering or distortion phenomena, indicating that the MOF-626 single crystal can achieve stable storage of complex information under the action of precisely controlled femtosecond lasers. This result further confirms that MOF-626 can not only store regular geometric patterns but also stably store complex patterns.

[0106] The method of the present invention improves the stability of optical information storage:

[0107] Traditional optical storage materials (such as organic dyes, polymers, inorganic semiconductors) are prone to be affected by factors such as photoaging, environmental humidity, and temperature changes during long-term use, resulting in poor stability of the stored information, and the stored data decays or even is lost over time; the present invention uses Ni-MOF-626 as an optical storage carrier. Its high specific surface area and regular pore structure effectively inhibit the diffusion of photoinitiators and monomers, avoid molecular aggregation, degradation, or migration, improve the stability of the stored information, and extend the storage life; through the structural optimization of MOF-626, it has excellent chemical stability and thermal stability, can maintain the stored information for a long time, and overcomes the problem of performance degradation of traditional optical storage materials during long-term use.

[0108] Improve the storage density and information storage accuracy of optical storage:

[0109] Traditional optical information storage technologies usually rely on the single-photon absorption mechanism. The minimum storage unit is limited by the diffraction limit, resulting in a limited storage density and unable to meet the requirements of future high-precision and large-capacity information storage. This invention adopts the two-photon polymerization technology to construct nanoscale storage patterns inside the MOF-626 crystal, realizing sub-micron-level optical information storage, breaking through the resolution limit of traditional single-photon storage, and improving the storage density and information accuracy. By precisely controlling the optical storage position with femtosecond lasers, an information storage lattice can be formed in three-dimensional space, achieving ultra-high-density information storage, far exceeding the storage capacity of existing optical storage materials.

[0110] Optimize the loading capacity of photoinitiators and monomers:

[0111] Due to their small pore sizes (generally less than 1 nm), traditional MOF structures (such as MOF-5 and DMOF) result in limited loading amounts of photoinitiators and monomers, affecting the efficiency and uniformity of subsequent polymerization reactions.

[0112] This invention adjusts the pore sizes of MOF-616, MOF-626, and MOF-636, enabling their pore size ranges to be adjustable to 2 - 4 nm. Compared with MOF-5 and DMOF, they can load more types of photoinitiators and monomers, increasing the loading amount and broadening the applicable range of optical storage materials. Through methods such as solvent exchange and impregnation, the photoinitiators and monomers are evenly distributed inside MOF-626, improving the homogeneity and controllability of the stored information, thereby optimizing the performance of the optical storage materials.

[0113] Enhance the controllability of information storage:

[0114] Traditional optical storage technologies are difficult to precisely control the loading amount, storage density, and storage depth of stored information, resulting in low storage flexibility. This invention utilizes the adjustable pore sizes of the MOF structure. By adjusting the photoinitiator concentration, photopolymerization parameters, and MOF loading ratio, the depth, intensity, and resolution of the stored information can be precisely controlled to meet different application requirements; by adjusting the focal depth and power of the laser, three-dimensional storage can be performed at different depths inside the MOF-626 single crystal, achieving higher storage flexibility and being applicable to multi-level information storage and encryption applications.

[0115] Improve the stability and environmental resistance of optical information storage:

[0116] Existing optical storage materials (such as photochromic materials and polymer-based optical storage) are prone to information fading, blurring or disappearing after long-term storage. Ni-MOF-626 has a high anti-photodamage ability, and its highly stable metal-organic framework structure can effectively prevent the diffusion of photopolymerization products, improving the durability and environmental adaptability of information storage. Through characterization techniques such as XRD, SEM, and AFM, it is confirmed that the MOF optical storage material of the present invention maintains its crystal structure unchanged before and after optical storage, and can still stably store information under environments with changes in light, humidity, and temperature, avoiding the deterioration problems of traditional materials.

[0117] Expand the applications of optical storage materials in the fields of high-density storage, security encryption, and information anti-counterfeiting:

[0118] Traditional optical storage technologies are limited in applications such as information encryption and security anti-counterfeiting, and it is difficult to meet the requirements of high-security information storage. The present invention uses MOF-626 as the optical storage substrate, and through femtosecond laser-induced two-photon polymerization technology, three-dimensional graphics, dot matrices, and complex LOGO patterns are stored inside the crystal, which is suitable for fields such as information anti-counterfeiting, identity authentication, and secure encrypted storage; since the stored information of MOF-626 is difficult to tamper with and cannot be read by ordinary methods, it can be applied to new information storage fields such as optical encryption technology, invisible data storage, and anti-counterfeiting labels.

[0119] Improve the scalability and future application potential of optical storage materials:

[0120] The MOF system proposed by the present invention is applicable to a variety of metal centers (Ni 2+ , Co 2+ , Cu 2+ , Rh 2+ , Pd 2+ ), and can be optimized according to actual application requirements to make it have a wider adaptability.

[0121] By adjusting the MOF structure, the present invention can be applicable to different laser parameters and storage requirements, and can be extended to fields such as high-precision lithography, photonic chips, super-resolution microscopy, and photonic computing, providing a material basis for future new optical storage and photonic technologies.

[0122] The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited by this. Any changes made on the basis of the technical solution according to the technical idea proposed by the present invention fall within the protection scope of the claims of the present invention.

Claims

1. A preparation method of a mesoporous MOF optical storage material, characterized in that, Comprising the following steps: Dissolve a metal salt, ZrOCl₂·8H₂O and an organic ligand in a solvent, and then add a carboxylic acid compound to the solvent to obtain a reaction solution; Carry out a heating reaction on the reaction solution. After the reaction is completed, post-treat the obtained reaction product to obtain a mesoporous MOF optical storage material; The organic ligand is 2,6-dimethyl-4-pyridin-4-ylbenzoic acid, 2',5'-dimethyl-4'-(pyridin-4-yl)-1,1'-biphenyl-4-ylbenzoic acid or isonicotinic acid.

2. The preparation method of a mesoporous MOF optical storage material according to claim 1, wherein, The metal ion in the metal salt is Ni 2+ , Co 2+ , Cu 2+ , Rh 2+ and Pd 2+ and is one of them.

3. The preparation method of a mesoporous MOF optical storage material according to claim 1, characterized in that, The dosage ratio of the metal salt, ZrOCl₂·8H₂O, the organic ligand and the solvent is (7.5 - 18) mg : (4.5 - 10) mg : (13 - 30) mg : 1 mL.

4. The preparation method of a mesoporous MOF optical storage material according to claim 1, characterized in that, The carboxylic acid compound is trifluoroacetic acid or benzoic acid; When it is trifluoroacetic acid, the volume ratio of the trifluoroacetic acid to the solvent is 30 μL : 1 mL; When it is benzoic acid, the dosage ratio of the benzoic acid to the solvent is 20 mg : 1 mL.

5. The preparation method of a mesoporous MOF optical storage material according to claim 1, characterized in that, The metal salt is one of nickel nitrate hexahydrate, copper nitrate hexahydrate, palladium nitrate, rhodium nitrate dihydrate, cobalt nitrate hexahydrate and nickel nitrate hexahydrate.

6. The preparation method of a mesoporous MOF optical storage material according to claim 1, characterized in that, The heating reaction is carried out in an oven; the temperature in the oven is (80 - 100) °C, and the heating reaction time is 24 - 48 h.

7. A mesoporous MOF optical storage material, characterized in that, Prepared by using the preparation method described in any one of claims 1 - 6; The pore diameter of the mesoporous MOF optical storage material is 2 - 4 nm.

8. Use of the mesoporous MOF optical storage material according to claim 7 in optical information storage, characterized in that, Comprising the following steps: Load a photoinitiator and a monomer inside the pores of the mesoporous MOF optical storage material to obtain a two-photon polymerization optical storage material of mesoporous MOF; Subsequently, form a storage pattern inside the two-photon polymerization optical storage material of mesoporous MOF through a two-photon polymerization reaction to achieve optical information storage.

9. The application of the mesoporous MOF optical storage material according to claim 8 in optical information storage, characterized in that, The method for loading the photoinitiator and the monomer is solvent exchange or impregnation method; the molecules of the photoinitiator and the monomer can enter the pores of the mesoporous MOF optical storage material.

10. The application of the mesoporous MOF optical storage material according to claim 8 in optical information storage, characterized in that, The two-photon polymerization reaction is realized by femtosecond laser processing inside a single crystal of the mesoporous MOF optical storage material.

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