Anion free radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material and its preparation method and application

Abstract

The present application discloses a two-dimensional paramagnetic conductive metal-organic framework material enhanced by anionic free radicals, its preparation method and application, and relates to the technical field of paramagnetic conductive materials. The preparation method comprises: dissolving nickel nitrate hexahydrate in a dispersion 1 of degassed dimethyl sulfoxide containing ammonia water and mixing hexaminobenzene hydrochloride in a dispersion 2 of degassed dimethyl sulfoxide and heating the mixture to obtain a two-dimensional metal-organic framework with semiconductor characteristics, and dispersing the mixture in an N, N-dimethylformamide solution containing tetrachlorobenzoquinone for reaction to obtain a two-dimensional paramagnetic conductive metal-organic framework material enhanced by anionic free radicals. In the present application, it was observed that the distance between Ni1-Ni4 in each pore of Ni3(HIB)2 was 1.35nm, and the distance between Cl1-Cl3 where tetrachlorobenzoquinone was in the para position was 0.61nm, which indicates that the pores of Ni3(HIB)2 can better accommodate tetrachlorobenzoquinone guests to form Ni3(HIB)2-CHL charge transfer complexes. By accommodating tetrachlorobenzoquinone in the pores of Ni3(HIB)2, conductivity and paramagnetism can be adjusted.

Description

Technical Field

[0001] The present application relates to the field of paramagnetic conductive materials, and in particular to a two-dimensional paramagnetic conductive metal-organic framework material enhanced by anion free radicals, and a preparation method and application thereof. Background Art

[0002] Metal-organic frameworks (MOFs) are a class of crystalline porous materials formed by linking metal nodes / clusters with organic ligands through coordination bonds. Due to their large specific surface area, adjustable pore size, and surface functional groups, they have attracted great interest in various fields such as electrocatalysis, chemiresistor sensors, supercapacitors, and batteries. Among related technologies, improving the conductivity of two-dimensional MOF materials and introducing magnetism have become research hotspots. Two-dimensional conjugated MX4-type (M = metal, X = NH, S, or O) MOFs are composed of planar organic ligands (i.e., benzene, triphenylene, etc. with thiol, hydroxyl, or amino groups) and metal atoms (i.e., Ni, Cu, Co, or Fe), which can achieve relatively high conductivity.

[0003] Because two-dimensional materials possess unique electronic, physical, and chemical properties due to their atomically thin layer structure, high surface chemical activity, large surface-to-volume ratio, and strong chemical adsorption capacity, improving the conductivity and introducing magnetism into two-dimensional metal-organic frameworks (MOFs) has become a research hotspot. To date, research has focused on two-dimensional conjugated MX4-type (M = metal, X = NH, S, or O) MOFs. These MOFs are composed of planar organic ligands (e.g., benzene, triphenylene, etc., with thiol, hydroxyl, or amino groups) coordinated with metal atoms (e.g., Ni, Cu, Co, or Fe), and can achieve relatively high conductivity.

[0004] One method currently used to obtain conductive metal-organic frameworks is to introduce external guest molecules after synthesis. These guest molecules act as bridges between adjacent molecular building blocks of the metal-organic framework to promote charge transfer. Practice has shown that the addition of redox-active guests (such as 7,7,8,8-tetracyanobenzoquinone dimethane) is an effective strategy for achieving charge transfer through host-guest charge transfer interactions. For example, in the prior art, the conductivity of Cu3(BTC)2 (BTC = benzene-1,3,5-tricarboxylic acid) can be increased from 10 to 200 nm by immersing it in a 7,7,8,8-tetracyanobenzoquinone dimethane solution. -8 The S / cm was increased to 0.07 S / cm. Although the cross-linked conductive metal-organic framework is not conductive, this experimental method can provide a potential conductive pathway for various conductive metal-organic framework topologies.

[0005] Organic free radicals possess one or more unpaired electrons that can impart unique physicochemical properties to materials, such as magnetism and electronics. Since most organic free radicals are generally highly reactive and unstable, two effective strategies have been established to construct materials containing organic radicals: introducing groups to prevent radical oligomerization reactions and delocalizing the unpaired electrons of free radicals by forming conjugated structures. In this context, two-dimensional conjugated metal-organic frameworks (MOFs), a class of crystalline polymer materials formed by regularly linking organic ligands with metal ions or clusters with coordination bonds, can effectively immobilize and stabilize organic radicals by delocalizing the unpaired electrons in the conjugated structure. Furthermore, the incorporation of organic radicals into MOFs has been shown to induce unique physicochemical properties, such as spin switching and electrical conductivity.

[0006] Therefore, it is very necessary to find a simple and efficient method to fix organic radicals in metal-organic frameworks. Summary of the Invention

[0007] In order to solve the above-mentioned technical problems existing in the prior art, the present application provides an anion free radical enhanced two-dimensional paramagnetic conductive metal-organic framework material and its preparation method and application, so as to overcome the technical problems such as poor conductivity and paramagnetism of the metal-organic framework in the prior art.

[0008] In order to achieve the above objectives, the technical solutions of the embodiments of the present application are:

[0009] The first aspect of the present application provides a method for preparing an anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material, comprising:

[0010] Dissolving nickel nitrate hexahydrate in degassed dimethyl sulfoxide containing aqueous ammonia to form a first dispersion; dissolving hexaaminobenzene hydrochloride in the degassed dimethyl sulfoxide to form a second dispersion;

[0011] mixing the first dispersion and the second dispersion and performing a heating reaction to collect a two-dimensional metal-organic framework having semiconductor characteristics;

[0012] The two-dimensional metal-organic framework with semiconductor characteristics is dispersed in an N,N-dimethylformamide solution containing tetrachlorobenzoquinone, and after heating reaction and purification treatment under an inert gas atmosphere, an anion free radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material is collected.

[0013] In combination with the first aspect, preferably, the molar ratio of the nickel nitrate hexahydrate to the hexaminobenzene hydrochloride is 3:2.

[0014] In combination with the first aspect, preferably, the mass ratio of the two-dimensional metal-organic framework with semiconductor characteristics to the tetrachlorobenzoquinone is 2:3.

[0015] In combination with the first aspect, preferably, the collecting of the two-dimensional metal-organic framework with semiconductor characteristics includes: obtaining a black solid by filtration, washing it with deionized water and acetone in sequence, and drying it in a vacuum oven to obtain the two-dimensional metal-organic framework with semiconductor characteristics.

[0016] In combination with the first aspect, preferably, when the first dispersion liquid and the second dispersion liquid are mixed and heated to react, the reaction temperature is 68° C. and the reaction time is 2 h.

[0017] In combination with the first aspect, preferably, when dispersing the two-dimensional metal-organic framework with semiconductor characteristics in an N,N-dimethylformamide solution containing tetrachlorobenzoquinone, the ultrasonic time is 10 to 15 minutes.

[0018] In combination with the first aspect, preferably, when the heating reaction is carried out under an inert gas atmosphere, the reaction temperature is 100° C. and the reaction time is 2 h.

[0019] In combination with the first aspect, preferably, the anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material includes a (100) crystal plane, a (200) crystal plane, a (3ī0) crystal plane, a (300) crystal plane, and a (001) crystal plane.

[0020] The second aspect of the present application provides a two-dimensional paramagnetic conductive metal-organic framework material enhanced by anion free radicals as described in the first aspect.

[0021] The third aspect of the present application provides an application of an anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material prepared by the method described in the first aspect or an anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material described in the second aspect for preparing a paramagnetic conductive material.

[0022] Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

[0023] The preparation method provided in this application is to fix tetrachlorobenzoquinone on a metal-organic framework by hydrogen bonding the carbonyl group of tetrachlorobenzoquinone and the metal-organic framework to obtain a two-dimensional paramagnetic conductive metal-organic framework material enhanced by anion free radicals. In this application, the structure of the two-dimensional metal-organic framework Ni3(HIB)2 with semiconductor characteristics was first simulated, and it was observed that the distance between Ni1-Ni4 in each pore of Ni3(HIB)2 was 1.35nm. At the same time, the structure of tetrachlorobenzoquinone was also simulated, and the distance between Cl1-Cl3 in the para position was 0.61nm, which shows that the pores of Ni3(HIB)2 can well accommodate tetrachlorobenzoquinone guests to form Ni3(HIB)2-CHL charge transfer complexes. The charge transfer in Ni3(HIB)2-CHL is generated by Ni(II) / (III) mixed valence atoms and tetrachlorobenzoquinone anion free radicals. In addition, charge transfer and additional in-plane charge transfer paths will occur after tetrachlorobenzoquinone is fixed in the pores of Ni3(HIB)2. Therefore, by accommodating chloranil in the pores of Ni3(HIB)2, the electrical conductivity and paramagnetism can be tuned. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Flow chart of the preparation of Ni3(HIB)2-CHL;

[0025] Figure 2 Structural simulation diagram of Ni3(HIB)2 and Ni3(HIB)2-CHL prepared in Example 1;

[0026] Figure 3 X-ray diffraction patterns of Ni3(HIB)2 and Ni3(HIB)2-CHL prepared in Example 1;

[0027] Figure 4 Solid-state electron paramagnetic resonance images of Ni3(HIB)2 and Ni3(HIB)2-CHL prepared in Example 1 and after standing for one month;

[0028] Figure 5 a) Magnetic susceptibility diagram of Ni3(HIB)2-CHL prepared in Example 1 measured at 3, 100 and 300 K as a function of magnetic field; Figure 5 b) is a trend diagram of the magnetization intensity of Ni3(HIB)2-CHL prepared in Example 1 as a function of temperature under an external magnetic field;

[0029] Figure 6 The conductivity of Ni3(HIB)2 and Ni3(HIB)2-CHL prepared in Example 1 changes with temperature;

[0030] Figure 7a) and c) are the simulated band structures and state density diagrams of Ni3(HIB)2-CHL and Ni3(HIB)2 prepared in Example 1; b) and d) are the calculated orbitals near the Fermi level of Ni3(HIB)2-CHL and Ni3(HIB)2 prepared in Example 1. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical solutions and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limiting this application. All other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0032] In the following description, reference is made to "some embodiments," which describe a subset of all possible embodiments. However, it will be understood that "some embodiments" may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of this application have the same meaning as commonly understood by those skilled in the art to which the embodiments of this application pertain. The terms used in the embodiments of this application are for the purpose of describing the embodiments of this application only and are not intended to limit this application.

[0033] In the following description of this embodiment, the terms "include", "comprising", "having" and "containing" are open-ended terms, meaning including but not limited to.

[0034] It should be noted that all raw materials / reagents in the examples of the present application can be purchased on the market or prepared according to conventional methods familiar to those skilled in the art; the term "and / or" in the examples of the present application is only used to describe the association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B represents three situations: A exists alone, B exists alone, and A and B exist at the same time, wherein A and B can be singular or plural, and the character " / " generally indicates that the previous and subsequent associated objects are in an "or" relationship.

[0035] In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all represent: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0036] Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0037] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0038] It will be understood by those skilled in the art that the numerical ranges in the examples of this application are to be understood as also specifically disclosing each intermediate value between the upper and lower limits of the ranges. Each smaller range between any stated value and the intermediate value in the stated range, as well as any other stated value or intermediate value in the stated range, is also encompassed by this application. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

[0039] Unless otherwise indicated, the technical / scientific terms used herein have the same meanings as those generally understood by those skilled in the art described in this application. Although this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the embodiments or test examples of this application. All documents mentioned in this specification are generally incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of any conflict with any incorporated document, the content of this application shall prevail.

[0040] It should be noted that all raw materials and / or reagents in the examples of the present application were purchased on the market or prepared according to conventional methods well known to those skilled in the art.

[0041] In a first aspect, the present invention provides a method for preparing an anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material, the preparation method comprising:

[0042] S10: dissolving nickel nitrate hexahydrate in degassed dimethyl sulfoxide containing aqueous ammonia to form a first dispersion; dissolving hexaminobenzene hydrochloride in the degassed dimethyl sulfoxide to form a second dispersion;

[0043] S20: mixing the first dispersion liquid and the second dispersion liquid and heating them to react, collecting a two-dimensional metal-organic framework having semiconductor characteristics;

[0044] S30: dispersing the two-dimensional metal-organic framework with semiconductor characteristics in an N,N-dimethylformamide solution containing tetrachlorobenzoquinone, performing heating reaction and purification treatment under an inert gas atmosphere, and collecting the two-dimensional paramagnetic conductive metal-organic framework material enhanced by anion free radicals.

[0045] The preparation method provided in this application is to fix tetrachlorobenzoquinone on a metal-organic framework by hydrogen bonding the carbonyl group of tetrachlorobenzoquinone and the metal-organic framework to obtain a two-dimensional paramagnetic conductive metal-organic framework material enhanced by anion free radicals. In this application, the structure of the two-dimensional metal-organic framework Ni3(HIB)2 with semiconductor characteristics was first simulated, and it was observed that the distance between Ni1-Ni4 in each pore of Ni3(HIB)2 was 1.35nm. At the same time, the structure of tetrachlorobenzoquinone was also simulated, and the distance between Cl1-Cl3 in the para position was 0.61nm, which shows that the pores of Ni3(HIB)2 can well accommodate tetrachlorobenzoquinone guests to form Ni3(HIB)2-CHL charge transfer complexes. The charge transfer in Ni3(HIB)2-CHL is generated by Ni(II) / (III) mixed valence atoms and tetrachlorobenzoquinone anion free radicals. In addition, charge transfer and additional in-plane charge transfer paths will occur after tetrachlorobenzoquinone is fixed in the pores of Ni3(HIB)2. Therefore, by accommodating chloranil in the pores of Ni3(HIB)2, the electrical conductivity and paramagnetism can be tuned.

[0046] In the preparation method step S10 provided in the present application, there is no restriction on the specific implementation method of dissolving, for example, stirring can be carried out under heating conditions, or dissolving can be carried out under room temperature conditions, as long as nickel nitrate hexahydrate can be evenly dispersed in degassed dimethyl sulfoxide containing ammonia; or as long as hexaaminobenzene hydrochloride can be evenly dispersed in degassed dimethyl sulfoxide. Therefore, as long as the mixing method that can make each raw material component fully mixed is within the scope disclosed in the embodiment specification of the present application, such as stirring, ultrasound and other methods, the mixing treatment can be carried out. There are no special requirements for the dissolving conditions such as temperature and time. As long as the dissolution and mixing efficiency of components such as nickel nitrate hexahydrate and hexaaminobenzene hydrochloride in degassed dimethyl sulfoxide containing ammonia can be improved, all can be considered and implemented. In the present application, the stirring speed can be 1000-5000rpm, and the stirring time can be 10-15min.

[0047] It should be noted that degassed dimethyl sulfoxide containing ammonia water is selected in the above step S10 because the ligand hexaminobenzene hydrochloride is an acidic substance. The addition of ammonia water can adjust the pH of the reaction on the one hand, which is beneficial to the synthesis of MOF, and on the other hand, it can assist in the dissolution of nickel nitrate hexahydrate in dimethyl sulfoxide; dimethyl sulfoxide is degassed because the synthesis of the MOF requires the participation of oxygen, but degassing in advance can reduce the oxygen content in the solution, help reduce the reaction rate, and improve the crystallinity of MOF.

[0048] In step S20 of the preparation method provided in the present application, the first dispersion and the second dispersion can be mixed and heated to react at a reaction temperature of 68° C. for a reaction time of 2 h to collect a two-dimensional metal-organic framework with semiconductor characteristics.

[0049] In a specific embodiment, the molar ratio of nickel nitrate hexahydrate to hexaaminobenzene hydrochloride in the embodiments of the present application is preferably 3:2.

[0050] It should be noted that the added volumes of the first and second dispersions are identical; the difference lies in the molar ratio of the metal (nickel nitrate hexahydrate) to the ligand (hexaaminobenzene hydrochloride) in the solutions, which is 3:2. The resulting MOF is Ni3(HIB)2. In this application, the molar ratio of nickel nitrate hexahydrate to hexaaminobenzene hydrochloride is precisely controlled to ensure a complete coordination reaction and minimize defects.

[0051] In a specific embodiment, the mass ratio of the two-dimensional metal-organic framework with semiconductor characteristics and tetrachlorobenzoquinone in the embodiments of the present application is preferably 2:3.

[0052] It should be noted that the mass ratio between the semiconducting 2D MOF and chloranil was fixed at 2:3. At this mass ratio, chloranil significantly outweighs the semiconducting 2D MOF content. This is because it is necessary to allow as much chloranil as possible to enter the MOF pores to control the paramagnetism and conductivity of the final product (anion radical-enhanced 2D paramagnetic conductive MOF). The total mass concentration was controlled at 10 mg / mL, which provides the highest product yield.

[0053] In a specific embodiment, the collection of a two-dimensional metal-organic framework with semiconductor characteristics in the embodiment of the present application includes: obtaining a black solid by filtration, washing it with deionized water and acetone in sequence, and drying it in a vacuum oven to obtain the two-dimensional metal-organic framework with semiconductor characteristics, which can be recorded as Ni3(HIB)2.

[0054] In a specific embodiment, when the first dispersion and the second dispersion are heated to react in the embodiment of the present application, the reaction temperature is preferably 68° C., and the reaction time is preferably 2 h.

[0055] In a specific embodiment, when the two-dimensional metal-organic framework with semiconductor characteristics is dispersed in an N,N-dimethylformamide solution containing tetrachlorobenzoquinone in the embodiment of the present application, the ultrasonic time is preferably 10 to 15 minutes.

[0056] It should be noted that the purpose of performing ultrasound in this application is to disperse the two-dimensional metal-organic framework with semiconductor characteristics more evenly, to avoid its precipitation and agglomeration in the solution, and thus to facilitate the loading of tetrachlorobenzoquinone.

[0057] In a specific embodiment, the two-dimensional paramagnetic conductive metal-organic framework material enhanced by anion free radicals in the embodiment of the present application includes a (100) crystal plane, a (200) crystal plane, a (3ī0) crystal plane, a (300) crystal plane, and a (001) crystal plane.

[0058] Correspondingly, the anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material can be recorded as Ni3(HIB)2-CHL.

[0059] It should be noted that the anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material has the amino functional group of the hexaaminobenzene ligand and the C-Cl bond functional group of tetrachlorobenzoquinone.

[0060] In a second aspect, an embodiment of the present application provides an anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material prepared by the method described in the first aspect.

[0061] In a third aspect, an embodiment of the present application provides an anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material prepared by the method described in the first aspect, or an anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material described in the second aspect for use in the preparation of paramagnetic conductive materials.

[0062] The technical method of the present application will be further described below with reference to specific embodiments.

[0063] Example 1

[0064] This embodiment provides a method for preparing a two-dimensional paramagnetic conductive metal-organic framework material enhanced by anion free radicals, and the specific steps are as follows:

[0065] Step 1: Dissolve (32 mg, 0.11 mmol) nickel nitrate hexahydrate in 3 mL of degassed dimethyl sulfoxide containing 0.7 mL of aqueous ammonia to form a first dispersion; dissolve (20 mg, 0.072 mmol) hexaaminobenzene hydrochloride in 3 mL of degassed dimethyl sulfoxide to form a second dispersion;

[0066] Step 2: mixing the first dispersion and the second dispersion and heating them for reaction at 68°C for 2 hours to collect a two-dimensional metal-organic framework with semiconductor characteristics;

[0067] Step 3: The two-dimensional metal-organic framework with semiconductor characteristics (200 mg, 0.39 mmol) was dispersed in 50 mL of N,N-dimethylformamide solution containing (300 mg, 1.23 mmol) of tetrachlorobenzoquinone, and after heating reaction and purification treatment under an inert gas atmosphere, the anion free radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material was collected.

[0068] In this application, the amount of Ni3(HIB)2 and chloranil added is controlled to achieve the control of the number of chloranil connections and the uniformity of the connections on the metal-organic framework. Among them, Ni3(HIB)2 and chloranil are more easily connected at 120°C. When the reaction temperature is controlled to 120°C and the reaction time is 3 days, on the one hand, it can be used to control the successful connection of Ni3(HIB)2 and chloranil, and on the other hand, it can maintain the structural integrity of Ni3(HIB)2 and the exposure of the (100) crystal plane, (200) crystal plane, (3ī0) crystal plane, (300) crystal plane, and (001) crystal plane, such as Figure 3 shown.

[0069] It should be noted that the reaction product is treated with deionized water and acetone in sequence in order to remove impurities such as unreacted precursors.

[0070] In order to confirm the formation of tetrachlorobenzoquinone anion radical in Ni3(HIB)2-CHL, Ni3(HIB)2-CHL powder was studied by solid-state electron paramagnetic resonance spectroscopy.

[0071] according to Figure 4 The solid-state electron paramagnetic resonance spectrum of Ni3(HIB)2-CHL shows a sharp peak with a g value of 2.002, indicating the formation of organic anion radicals in Ni3(HIB)2-CHL. For the Ni3(HIB)2-CHL powder sample stored in air for one month, approximately 33.6% of the organic anion radicals were retained, indicating that these anion radicals have relatively good stability in air.

[0072] Magnetic measurements of Ni3(HIB)2-CHL were performed on a SQUID magnetometer. Figure 5 a) Shows the variation of the magnetization intensity (M) of Ni3(HIB)2-CHL measured at 3K, 100K and 300K as a function of the applied magnetic field (B).

[0073] according to Figure 5It can be seen that a significant increase behavior is observed under a high magnetic field of 3K, indicating that Ni3(HIB)2-CHL has typical paramagnetic behavior. When the temperature drops below 50K, the magnetization intensity of Ni3(HIB)2-CHL increases sharply. This shows that Ni3(HIB)2 has paramagnetism, and similar results are also observed in Ni3(HIB)2.

[0074] Figure 6 The temperature-dependent electrical conductivity trends of bulk compressed particles of Ni3(HIB)2 and Ni3(HIB)2-CHL were investigated using a four-point probe method. The conductivity versus temperature plot shows that the electrical conductivity of granular Ni3(HIB)2 increases with increasing temperature, suggesting that the Ni3(HIB)2 particles exhibit semiconductor-like behavior. This thermally activated transport behavior is attributed to defects and small crystal size. Below 270 K, Ni3(HIB)2-CHL particles, similar to Ni3(HIB)2 particles, exhibit primarily semiconducting properties. However, unlike Ni3(HIB)2 particles, the electrical conductivity of bulk Ni3(HIB)2 particles exhibits a negative temperature dependence in the 270-300 K range, which is characteristic of metallic transport.

[0075] The present application shows metallic conductivity in metal-organic frameworks through the formation of charge-transfer complexes. These results indicate that charge transport in 2D conductive metal-organic frameworks can be modulated by forming charge-transfer complexes using host-guest chemistry.

[0076] Density functional theory (DFT) simulations were used in this application to further understand the charge transport properties of Ni3(HIB)2-CHL and Ni3(HIB)2. The electronic band structures calculated using DFT show that both Ni3(HIB)2-CHL and Ni3(HIB)2 have metallic transport properties, such as Figure 7 a and c. The density of states reveals significant contributions from Ni, C, and N orbitals at the Fermi level, confirming the presence of a high degree of planar π conjugation in these materials, as shown in Figure 7 a and c. The calculated orbitals near the Fermi level indicate that the addition of chlorobenzoquinone may generate supplementary charge carriers and additional conductive pathways in the Ni3(HIB)2-CHL material, as shown in Figure 7 a and c. These results explain the metallic conductivity observed in Ni3(HIB)2-CHL.

[0077] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A method for preparing a two-dimensional paramagnetic conductive metal-organic framework material enhanced by anion free radicals, characterized in that: include: Dissolving nickel nitrate hexahydrate in degassed dimethyl sulfoxide containing aqueous ammonia to form a first dispersion; dissolving hexaaminobenzene hydrochloride in the degassed dimethyl sulfoxide to form a second dispersion; mixing the first dispersion and the second dispersion and performing a heating reaction to collect a two-dimensional metal-organic framework having semiconductor characteristics; The two-dimensional metal-organic framework with semiconductor characteristics is dispersed in an N,N-dimethylformamide solution containing tetrachlorobenzoquinone, and after heating reaction and purification treatment under an inert gas atmosphere, an anion free radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material is collected.

2. The method for preparing anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material according to claim 1, characterized in that: The molar ratio of the nickel nitrate hexahydrate to the hexaminobenzene hydrochloride is 3:

2.

3. The method for preparing anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material according to claim 1, characterized in that: The mass ratio of the two-dimensional metal organic framework with semiconductor characteristics to the tetrachlorobenzoquinone is 2:

3.

4. The method for preparing anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material according to claim 1, characterized in that: The collecting of the two-dimensional metal-organic framework with semiconductor characteristics comprises: obtaining a black solid by suction filtration, washing it with deionized water and acetone in sequence, and drying it in a vacuum oven to obtain the two-dimensional metal-organic framework with semiconductor characteristics.

5. The method for preparing anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material according to claim 1, characterized in that: When the first dispersion liquid and the second dispersion liquid are heated to react, the reaction temperature is 68° C. and the reaction time is 2 hours.

6. The method for preparing anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material according to claim 1, characterized in that: When the two-dimensional metal organic framework with semiconductor characteristics is dispersed in an N,N-dimethylformamide solution containing tetrachlorobenzoquinone, the ultrasonic time is 10 to 15 minutes.

7. The method for preparing anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material according to claim 1, characterized in that: When the heating reaction is carried out under an inert gas atmosphere, the reaction temperature is 100° C. and the reaction time is 2 h.

8. The method for preparing anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material according to claim 1, characterized in that: The anion free radical enhanced two-dimensional paramagnetic conductive metal organic framework material includes a (100) crystal plane, a (200) crystal plane, a (3ī0) crystal plane, a (300) crystal plane, and a (001) crystal plane.

9. An anion free radical enhanced two-dimensional paramagnetic conductive metal organic framework material prepared by the method according to any one of claims 1 to 8.

10. Use of an anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material prepared by the method of any one of claims 1 to 8 or the anion radical-enhanced two-dimensional paramagnetic conductive metal-organic framework material according to claim 9 in the preparation of a paramagnetic conductive material.

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