Electro-synthesis method capable of continuously preparing hydrogen bond organic framework film material

Abstract

The invention provides a synthesis method of a hydrogen-bond organic framework film material, namely an electric synthesis method capable of continuously preparing the hydrogen-bond organic framework film material, which comprises the following steps: (1) adding an organic ligand into a poor solvent or a mixed solvent formed by the poor solvent and a good solvent, and then adding alkali to clarify the solution; and (2) applying direct current to the prepared solution by taking a conductive substrate as a cathode and an anode, and collecting a product deposited on the conductive substrate after electrifying for a period of time, so as to obtain the hydrogen bond organic framework film material corresponding to the ligand. The method is simple and rapid, the compact HOF thin film can be rapidly deposited on the conductive substrate, and high-efficiency and continuous synthesis can be achieved. The synthesized HOF film material can be used in the field of electrochromism.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of porous material preparation, and particularly relates to an electro-synthesis method for continuously preparing hydrogen-bonded organic framework thin film materials. BACKGROUND

[0002] Hydrogen-bonded organic framework materials (HOFs) are a kind of novel crystalline materials with two-dimensional or three-dimensional porous structures formed by hydrogen bonds and other weak interaction forces through self-assembly. Due to its large specific surface area, high porosity, mild assembly conditions, easy regeneration and other characteristics, it has broad application prospects in the fields of gas adsorption and separation, catalysis, sensing and the like. However, the traditional synthesis method of HOF thin film materials is mainly to synthesize corresponding HOF materials through a solvent thermal method, a volatilization method or a diffusion method, and then to obtain HOF thin films through spin coating, drop coating or electrophoresis and the like. In the synthesis process, a large amount of solvent is consumed, the time is long, the energy consumption is large, and the prepared HOF thin film has the problem of poor compactness, which limits the mass preparation and subsequent application of the HOF thin film. Therefore, it is of great significance to develop an efficient and rapid synthesis method of HOF thin film materials. SUMMARY

[0003] In order to improve the above problems, the application provides a new synthesis method of hydrogen-bonded organic framework thin film materials, that is, an electro-synthesis method for continuously preparing hydrogen-bonded organic framework thin film materials. The method is simple and rapid, can quickly deposit a dense HOF thin film on a conductive substrate, and can realize efficient and continuous synthesis. The synthesized HOF thin film material can be used in the field of electrochromism.

[0004] The application first provides an electro-synthesis method for preparing hydrogen-bonded organic framework thin film materials, comprising:

[0005] (1) adding an organic ligand into a poor solvent or a mixed solvent composed of a poor solvent and a good solvent, and then adding a base to make the solution clear;

[0006] (2) taking a conductive substrate as a cathode and an anode, applying a direct current to the prepared solution, collecting the product deposited on the conductive substrate after a period of time, and the product is a hydrogen-bonded organic framework thin film material corresponding to the ligand.

[0007] According to the embodiment of the application, the method further comprises the following steps:

[0008] (3) after collecting the product for multiple times, without repeating the preparation of the solution, adding a corresponding organic ligand into the working solution, and repeating step (2), so that the continuous preparation of the hydrogen-bonded organic framework thin film material can be realized.

[0009] According to the embodiment of the application, the organic ligand in step (1) is a carboxylic acid ligand containing more than 3 COOH, and its general formula is X-[Q-(COOH)a ] b wherein;

[0010] X is selected from C, N, -C=C-, a group C 6-24 aryl, 5-24 membered heteroaryl, C 6-24 aryl-C 6-24 aryl, 5-24 membered heteroaryl-5-24 membered heteroaryl; the 5-24 membered heteroaryl optionally also forms a complex with a metal (e.g. Cu, Zn, Fe); and when X is selected from 5-24 membered heteroaryl or 5-24 membered heteroaryl-5-24 membered heteroaryl, X can be in its cationic form;

[0011] R1is selected from =O, amino, halogen or C 1-6 alkyl;

[0012] Q is selected from a bond, -C≡C-, C 6-24 aryl; when Q is a bond, a carboxylic acid group is directly attached to N; and when Q is a bond, X is not C or -C=C-;

[0013] R2is selected from halogen or C 1-6 alkyl;

[0014] a is selected from 1 or 2;

[0015] b is selected from 2, 3, 4, 5 or 6; and when a is 1, b is not 2.

[0016] According to embodiments of the present application, X is selected from a group C 6-24 aryl, 5-24 membered heteroaryl, C 6-24 aryl-C 6-24 aryl, 5-24 membered heteroaryl-5-24 membered heteroaryl; the 5-24 membered heteroaryl optionally also forms a complex with a metal Cu;

[0017] R1is selected from =O, amino or Cl;

[0018] Q is selected from a bond, -C≡C- or C 6-24 aryl;

[0019] a is selected from 1 or 2;

[0020] b is selected from 2, 3 or 4; and when a is 1, b is not 2.

[0021] According to embodiments of the present application, X is selected from C, N or -C=C-;

[0022] Q is selected from C 6-24 aryl;

[0023] a is selected from 1 or 2;

[0024] b is selected from 1, 2, 3 or 4; and when a is 1, b is not 2.

[0025] According to embodiments of the present application, X is selected from C, -C≡C-, a group unsubstituted or optionally substituted with one, two or more R1: pyrenyl, biphenyl, naphthyl, anthryl, phenyl, s-triazinyl,

[0026] and when Q is a bond, X is not C or -C=C-;

[0027] R1is selected from =O, amino or CI;

[0028] Q is selected from a bond, -C≡C-, phenyl or naphthyl;

[0029] a is selected from 1 or 2;

[0030] b is selected from 2, 3 or 4; and when a is 1, b is not 2.

[0031] According to embodiments of the present application, the organic ligand is selected from the following structures:

[0032]

[0033]

[0034] According to embodiments of the present application, the good solvent in step (1) can be selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide; the poor solvent can be selected from at least one of water, methanol, ethanol, isopropanol or acetonitrile;

[0035] According to embodiments of the present application, when the good solvent and the poor solvent are used simultaneously, the volume ratio of the good solvent to the poor solvent is 1:(3-20), for example 1:(5-15), such as 1:10;

[0036] According to embodiments of the present application, the base in step (1) can be selected from at least one of sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, aqueous ammonia, aqueous tetramethylammonium hydroxide, aqueous tetraethylammonium hydroxide, aqueous tetrapropylammonium hydroxide or aqueous tetrabutylammonium hydroxide;

[0037] According to embodiments of the present application, the molar ratio of the organic ligand to the base is 1:(1-10), for example 1:(2-4), such as 1:3;

[0038] According to an embodiment of the present application, the conductive substrate in step (2) can be selected from at least one of carbon paper, ITO conductive glass, FTO conductive glass, foamed copper, foamed nickel or silicon wafer;

[0039] According to an embodiment of the present application, the voltage in step (2) is not less than 3V, for example 3-80V, such as 5-30V or 10-25V; the time of power on in step (2) is not less than 10s, for example 10-600s, such as 60-300s or 120-240s.

[0040] According to an embodiment of the present application, when the organic ligand is selected from 1,3,6,8-tetrakis(p-carboxyphenyl)pyrene, 1,3,6,8-tetracarboxypyrene, 6,6',6",6"'-(pyrene-1,3,6,8-tetramethylphenyl) tetrakis(2-naphthalenecarboxylic acid), 1,3,5-tris(3,5-dicarboxyphenyl ethynyl) benzene or N,N'-di(5-m-phthaloyl) naphthalene diimide, the good solvent used is N,N-dimethylformamide, and the poor solvent is selected from at least one of water, methanol, ethanol or acetonitrile; the volume ratio of the good solvent to the poor solvent is 1:(10-20).

[0041] According to an embodiment of the present application, when the organic ligand is selected from 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid, the poor solvent used is selected from ethanol.

[0042] The present application also provides a hydrogen-bonded organic framework thin film material prepared by the method as described above.

[0043] According to an embodiment of the present application, the hydrogen-bonded organic framework thin film material is PFC-1, HOF-100, HOF-102, HOF-TCBP, PFC-67, PFC-76-Tdz or PFC-70;

[0044] PFC-1 is a square layer topology (sql) network formed by ligand 1,3,6,8-tetrakis(p-carboxyphenyl)pyrene through four pairs of hydrogen bonds with four surrounding ligand units, a hydrogen-bonded organic framework material with two-dimensional stacking structure constructed by interlayer π-π interaction; preferably, the particle size of the obtained PFC-1 is 2-15μm by the preparation method described above;

[0045] HOF-100 is a square layer topology (sql) network formed by ligand 1,3,6,8-tetracarboxypyrene through four pairs of hydrogen bonds with four surrounding ligand units, a hydrogen-bonded organic framework material with two-dimensional stacking structure constructed by interlayer π-π interaction; preferably, the particle size of the obtained HOF-100 is 2-10μm by the preparation method described above;

[0046] HOF-102 is a square layer (sql) network formed by ligand 6,6',6”,6”'-(pyrene-1,3,6,8-tetramethylphenyl) tetrakis(2-naphthalenecarboxylic acid) through four pairs of hydrogen bonds with four surrounding ligand units, a hydrogen-bonded organic framework material with two-dimensional stacking structure constructed by interlayer π-π interaction; preferably, the particle size of the obtained HOF-102 is 2-10 μm by the above preparation method;

[0047] HOF-TCBP is a five-fold interpenetrated hydrogen-bonded organic framework material with diamond topology (dia) network formed by ligand diphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid) through four pairs of hydrogen bonds with four surrounding ligand units; preferably, the particle size of the obtained HOF-TCBP is 10-30 μm by the above preparation method;

[0048] PFC-67 is a honeycomb (hcb) network formed by ligand 1,3,5-tris(3,5-dicarboxyphenyl ethynyl) benzene through six pairs of hydrogen bonds with three surrounding ligand units, a hydrogen-bonded organic framework material with two-dimensional stacking structure constructed by interlayer π-π interaction; preferably, the particle size of the obtained PFC-67 is 500 nm-1 μm by the above preparation method;

[0049] PFC-76-Tdz is a square layer (sql) network formed by ligand 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl) dibenzenedicarboxylic acid through four pairs of hydrogen bonds with four surrounding ligand units, a hydrogen-bonded organic framework material with two-dimensional stacking structure constructed by interlayer π-π interaction; preferably, the particle size of the obtained PFC-76-Tdz is 2-20 μm by the above preparation method;

[0050] PFC-70 is a honeycomb (Square layer, sql) network formed by ligand N,N'-di(5-m-phenylenedicarboxyl) naphthalimide through four pairs of hydrogen bonds with four surrounding ligand units, a hydrogen-bonded organic framework material with two-dimensional stacking structure constructed by interlayer π-π interaction; preferably, the particle size of the obtained PFC-70 is 500 nm-2 μm by the above preparation method.

[0051] The method of the present application can be used for the continuous synthesis of HOF thin film materials, that is, without reconfiguring the solution environment as the reaction proceeds, only the corresponding ligand needs to be added, and step (2) can be repeated to obtain the corresponding HOF thin film material. Preferably, the amount of organic ligand re-added is 50%-80% of the molar amount of organic ligand added in step (1), for example, 60%-70%.

[0052] The present invention also provides use of the hydrogen-bonded organic framework thin film material for preparing an electrochromic material.

[0053] Compared with the prior art, the method of the present invention has the following advantages:

[0054] (1) The present invention discloses an electrosynthesis method for continuously preparing hydrogen-bonded organic framework thin film materials. The method is simple and efficient, and can realize the direct synthesis from ligands to HOF thin film materials, avoiding the tedious steps of first synthesis and then film formation in traditional methods; the HOF thin film material generated in situ on a conductive substrate has good density and can be directly used in subsequent related applications, such as electrochromic devices.

[0055] (2) The synthesis method provided by the present invention can realize the continuous synthesis of HOF thin film materials, greatly improving the synthesis efficiency of HOF thin film materials; the solution can be reused, avoiding the large amount of solution waste in traditional synthesis methods, and greatly saving the synthesis cost.

[0056] (3) The poor solvent used in the present invention has low toxicity, and some ligands can even be synthesized using water, which is green and environmentally friendly.

[0057] In summary, this method provides a new method for synthesizing HOF thin film materials. The method is simple to operate and can efficiently and quickly synthesize a variety of HOF thin film materials. Compared with traditional methods, it can greatly improve the utilization rate of solvents and reduce a large amount of resource waste. At the same time, this method can realize the continuous synthesis of HOF thin film materials, which is of great significance to the industrial preparation of HOF thin film materials.

[0058] Definitions and Explanations of Terms

[0059] In this application, some groups marked with “*” are connection sites.

[0060] The term "halogen" refers to fluorine, chlorine, bromine and iodine.

[0061] The term "C 1-6 The term "alkyl" should be understood as a linear or branched saturated hydrocarbon group having 1 to 6 carbon atoms, for example, selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, isopropyl, etc.

[0062] The term "C 6-24 "Aryl" should be understood to preferably mean an aromatic or partially aromatic single aromatic ring or polyaromatic rings fused together having 6 to 24 carbon atoms. Specifically including: "C6 aryl", such as phenyl or biphenyl; "C 10 Aryl", such as tetrahydronaphthyl, dihydronaphthyl or naphthyl; "C 13 Aryl", such as fluorenyl; "C 14 Aryl", such as anthracenyl or phenanthrenyl; "C 16“aryl”, for example pyrenyl; “C 18 “aryl”, for example 9,10-benzophenanthryl; “C 20 “aryl”, for example perylenyl.

[0063] The term “5-24 membered heteroaryl” is to be understood as preferably meaning a heteroaromatic ring or fused heteroaromatic rings having 5 to 24 ring atoms, wherein 1 to 7 atoms are independently selected from N, O or S, i.e. a heterocyclic compound or a fused heterocyclic compound. For example “5-14 membered heteroaryl”. The term “5-14 membered heteroaryl” is to be understood as including a monovalent monocyclic, bicyclic or tricyclic aromatic ring system having 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14 ring atoms, in particular 5 or 6 or 9 or 10 carbon atoms, and which contains 1 to 5, preferably 1 to 3, heteroatoms independently selected from N, O and S, and, in each case additionally, can be benzo-fused. In particular, the heteroaryl group is selected from thienyl, furanyl, pyrrolyl, oxazolyl, thiazolyl, imidazolyl, pyrazolyl, isoxazolyl, isothiazolyl, oxadiazolyl, triazolyl, thiadiazolyl, thia-4H-pyrazolyl and the like and their benzo derivatives, for example benzo furanyl, benzo thienyl, benzo oxazolyl, benzo isoxazolyl, benzo imidazolyl, benzo triazolyl, indazolyl, indolyl, isoindolyl and the like; or pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, triazinyl and the like and their benzo derivatives, for example quinolinyl, quinazolinyl, isoquinolinyl and the like; or azocinyl, indolizinyl, purinyl and the like and their benzo derivatives; or cinnolinyl, phthalazinyl, quinazolinyl, quinoxalinyl, naphthyridinyl, pteridinyl, carbazolyl, acridinyl, phenoxazinyl, phenothiazinyl, phenoxazinyl and the like. BRIEF DESCRIPTION OF DRAWINGS

[0064] Figure 1 Structure schematic of the hydrogen-bonded organic framework material prepared in Example 1 based on the ligand 1,3,6,8-tetra(p-carboxyphenyl)pyrene (PFC-1) and its single crystal simulation of PXRD;

[0065] Figure 2 Comparison chart of the PXRD of the hydrogen-bonded organic framework material (HOF-100) prepared in Example 2 based on the ligand 1,3,6,8-tetracarboxypyrene and its single crystal simulation of PXRD and scanning electron microscope image;

[0066] Figure 3 Comparison chart of the PXRD of the hydrogen-bonded organic framework material (HOF-102) prepared in Example 3 based on the ligand 6,6',6",6"'-(pyrene-1,3,6,8-tetramethylphenyl)tetra(2-naphthalenecarboxylic acid) and its single crystal simulation of PXRD and scanning electron microscope image;

[0067] Figure 4 Comparison chart of the PXRD of the hydrogen-bonded organic framework material (HOF-102) prepared in Example 3 based on the ligand 6,6',6",6"'-(pyrene-1,3,6,8-tetramethylphenyl)tetra(2-naphthalenecarboxylic acid) and its single crystal simulation of PXRD and scanning electron microscope image;

[0068] Figure 5 Comparison chart of PXRD and scanning electron microscopy image of hydrogen bonded organic framework material (HOF-TCBP) prepared based on ligand biphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid) prepared for Example 4 and its single crystal simulation;

[0069] Figure 6 Comparison chart of PXRD and scanning electron microscopy image of hydrogen bonded organic framework material (PFC-67) prepared based on ligand 1,3,5-tris(3,5-dicarboxyphenyl ethynyl) benzene prepared for Example 5 and its single crystal simulation;

[0070] Figure 7 Comparison chart of PXRD and scanning electron microscopy image of hydrogen bonded organic framework material (PFC-76-Tdz) prepared based on ligand 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid prepared for Example 6 and its single crystal simulation;

[0071] Figure 8 Comparison chart of PXRD and scanning electron microscopy image of hydrogen bonded organic framework material (PFC-70) prepared based on ligand N,N'-di(5-isophthalic acid) naphthalene diimide prepared for Example 7 and its single crystal simulation;

[0072] Figure 9 Comparison chart of PXRD and scanning electron microscopy image of aqueous phase electro-synthesis (PFC-1) based on ligand 1,3,6,8-tetra(p-carboxyphenyl) pyrene for Example 8 and its single crystal simulation;

[0073] Figure 10 UV-Vis absorption spectrum of ligand content change in 3 rounds of continuous preparation based on ligand 1,3,6,8-tetra(p-carboxyphenyl) pyrene for Example 9;

[0074] Figure 11 Cyclic voltammogram and color change phenomenon of thin film PFC-1 prepared based on Example 8 for electrochromic application;

[0075] Figure 12 Optical contrast and response time chart of thin film PFC-1 prepared based on Example 8 for electrochromic application;

[0076] Figure 13 Current and integral curve of electric quantity with time chart of thin film PFC-1 prepared based on Example 8 for electrochromic application.

[0077] Figure 14 Molecular formula of ligand raw material for preparing hydrogen bonded organic framework material listed in the present application. DETAILED DESCRIPTION

[0078] The technical solutions of the present application will be further described in detail below in combination with specific examples. It should be understood that the following examples are only illustratively described and explained, and should not be interpreted as limiting the scope of protection of the present application. Any technology realized based on the above description of the present application is covered within the scope of protection intended by the present application.

[0079] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0080] Part of the instrument information is as follows:

[0081] Electronic balance: Kunshan Shumei BS223S

[0082] Ultrasonic cleaner: Kunshan Shumei kq-250DB

[0083] Linear DC power supply: MCH-K1505D, M&C Instruments

[0084] X-ray diffractometer: Japan Rigaku SmartLab;

[0085] Scanning electron microscope: Phenom G6 ProX, FEI;

[0086] UV-Vis spectrophotometer: Shimadzu UV-2550;

[0087] Electrochemical workstation: Germany Zahner IM6

[0088] The aqueous solution of tetrabutylammonium hydroxide used in the following examples is an aqueous solution with a mass fraction of 40%.

[0089] Example 1 Hydrogen-bonded organic framework material (PFC-1) prepared based on ligand 1,3,6,8-tetrakis(p-carboxyphenyl)pyrene;

[0090] A solvent with a volume ratio of N,N-dimethylformamide and methanol of 1:10 was prepared, 10 mg of ligand 1,3,6,8-tetrakis(p-carboxyphenyl)pyrene was added, and after ultrasonic mixing, 20 μL of aqueous solution of tetrabutylammonium hydroxide was added, and the solution was ultrasonically clarified. Insert ITO conductive glass into the solution and apply a voltage of 5V for 2 minutes to obtain hydrogen-bonded organic framework thin film material PFC-1;

[0091] The powder XRD of PFC-1 is consistent with the simulated XRD of its single crystal, which indicates the successful synthesis of material PFC-1; scanning electron microscope (right) shows that the particle size of PFC-1 thin film material prepared by electrochemical synthesis is 2-15 μm. Figure 2 Figure 2 The powder XRD of PFC-1 is consistent with the simulated XRD of its single crystal, which indicates the successful synthesis of material PFC-1; scanning electron microscope (right) shows that the particle size of PFC-1 thin film material prepared by electrochemical synthesis is 2-15 μm.

[0092] ​Example 2 Hydrogen-bonded organic framework material (HOF-100) prepared based on ligand 1,3,6,8-tetracarboxypyrene;

[0093] A solvent of N,N-dimethylformamide, methanol and acetonitrile in a volume ratio of 1:10:10 was configured, 5 mg of ligand 1,3,6,8-tetracarboxypyrene was added, and after ultrasonic mixing, 20 μL of a tetrabutylammonium hydroxide aqueous solution was added, and ultrasonic mixing was performed until the solution was clear. ITO conductive glass was inserted into the solution and a voltage of 20 V was applied for 2 minutes to obtain a hydrogen-bonded organic framework thin film material HOF-100.

[0094] The powder XRD thereof coincides with the simulated XRD of the single crystal thereof Figure 3 The left) indicates the successful synthesis of material HOF-100; scanning electron microscopy Figure 3 The right) indicates that the particle size of the HOF-100 thin film material prepared by the electro-synthesis method is 2-10 μm.

[0095] Example 3 Hydrogen-bonded organic framework material (HOF-102) prepared based on ligand 6,6',6”,6”'-(pyrene-1,3,6,8-tetramethylphenyl) tetrakis(2-naphthalenecarboxylic acid);

[0096] A solvent of N,N-dimethylformamide and methanol in a volume ratio of 1:15 was configured, 5 mg of ligand 6,6',6”,6”'-(pyrene-1,3,6,8-tetramethylphenyl) tetrakis(2-naphthalenecarboxylic acid) was added, and after ultrasonic mixing, 12 μL of a tetrabutylammonium hydroxide aqueous solution was added, and ultrasonic mixing was performed until the solution was clear. Carbon paper was inserted into the solution and a voltage of 25 V was applied for 2 minutes to obtain a hydrogen-bonded organic framework thin film material HOF-102;

[0097] The powder XRD thereof coincides with the simulated XRD of the single crystal thereof Figure 4 The left) indicates the successful synthesis of material HOF-102; scanning electron microscopy Figure 4 The right) indicates that the particle size of the HOF-102 thin film material prepared by the electro-synthesis method is 2-10 μm.

[0098] Example 4 Hydrogen-bonded organic framework material (HOF-TCBP) prepared based on ligand diphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid);

[0099] A solvent of N,N-dimethylformamide and methanol in a volume ratio of 1:15 was configured, 5 mg of ligand diphenyl-3,3',5,5'-tetrakis-(phenyl-4-carboxylic acid) was added, and after ultrasonic mixing, 10 μL of a tetrabutylammonium hydroxide aqueous solution was added, and ultrasonic mixing was performed until the solution was clear. Carbon paper was inserted into the solution and a voltage of 10 V was applied for 2 minutes to obtain a hydrogen-bonded organic framework thin film material HOF-TCBP;

[0100] The powder XRD of PFC-67 is consistent with the simulated XRD of its single crystal Figure 5 The left) shows the successful synthesis of material HOF-TCBP; scanning electron microscopy Figure 5 The right) shows that the particle size of the HOF-TCBP thin film material prepared by the electro-synthesis method is 10-30 μm.

[0101] Example 5 Hydrogen-bonded organic framework material (PFC-67) prepared based on ligand 1,3,5-tris(3,5-dicarboxyphenyl ethynyl) benzene;

[0102] A solvent with a volume ratio of N,N-dimethylformamide and methanol of 1:15 was configured, 5 mg of ligand 1,3,5-tris(3,5-dicarboxyphenyl ethynyl) benzene was added, and after ultrasonic mixing, 12 μL of a tetrabutylammonium hydroxide aqueous solution was added, and ultrasonic mixing was performed until the solution was clear. ITO conductive glass was inserted into the solution and a voltage of 15 V was applied for 2 minutes to obtain a hydrogen-bonded organic framework thin film material PFC-67;

[0103] The powder XRD of PFC-67 is consistent with the simulated XRD of its single crystal Figure 6 The left) shows the successful synthesis of material PFC-67; scanning electron microscopy Figure 6 The right) shows that the particle size of the PFC-67 thin film material prepared by the electro-synthesis method is 500 nm-1 μm.

[0104] Example 6 Hydrogen-bonded organic framework material (PFC-76-Tdz) prepared based on ligand 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid;

[0105] A certain volume of ethanol was taken, 5 mg of ligand 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid was added, and after ultrasonic mixing, 8 μL of a tetrabutylammonium hydroxide aqueous solution was added, and ultrasonic mixing was performed until the solution was clear. ITO conductive glass was inserted into the solution and a voltage of 20 V was applied for 2 minutes to obtain a hydrogen-bonded organic framework thin film material PFC-76-Tdz;

[0106] The powder XRD of PFC-76-Tdz is consistent with the simulated XRD of its single crystal Figure 7 The left) shows the successful synthesis of material PFC-76-Tdz; scanning electron microscopy Figure 7 The right) shows that the particle size of the PFC-76-Tdz thin film material prepared by the electro-synthesis method is 2-20 μm.

[0107] Example 7 Hydrogen-bonded organic framework material (PFC-70) prepared based on ligand N,N'-di(5-isophthalic acid) naphthalene imide;

[0108] A solvent of N,N-dimethylformamide and methanol with a volume ratio of 1:10 was configured, 5 mg of ligand N,N'-di(5-m-phenylenedioxy) naphthalimide was added, and after ultrasonic mixing, 12 μL of a tetrabutylammonium hydroxide aqueous solution was added, and the solution was ultrasonically treated until it was clear. An ITO conductive glass was inserted into the solution, and a voltage of 20 V was applied for 2 minutes to obtain a hydrogen-bonded organic framework thin film material PFC-70;

[0109] The powder XRD thereof is consistent with the simulated XRD of the single crystal thereof Figure 8 The left) shows the successful synthesis of material PFC-70; scanning electron microscopy Figure 8 The right) shows that the particle size of the PFC-70 thin film material prepared by the electro-synthesis method is 500 nm-2 μm.

[0110] Example 8: Electro-synthesis of a hydrogen-bonded organic framework material (PFC-1) based on ligand 1,3,6,8-tetra(p-carboxyphenyl)pyrene in an aqueous phase;

[0111] A solvent of N,N-dimethylformamide and water with a volume ratio of 1:10 was configured, 5 mg of ligand 1,3,6,8-tetra(p-carboxyphenyl)pyrene was added, and after ultrasonic mixing, 14 μL of a tetrabutylammonium hydroxide aqueous solution was added, and the solution was ultrasonically treated until it was clear. An ITO conductive substrate was inserted into the solution, and a voltage of 5 V was applied for 1 minute to obtain a hydrogen-bonded organic framework thin film material PFC-1;

[0112] The powder XRD thereof is consistent with the simulated XRD of the single crystal thereof Figure 9 The left) shows the successful synthesis of material PFC-1; scanning electron microscopy Figure 9 The right) shows that the particle size of the PFC-1 thin film material prepared by the electro-synthesis method is in the nanometer scale.

[0113] It can be seen that the method of the application can use non-toxic water as the reaction system, which is green and environmentally friendly.

[0114] Example 9: Continuous synthesis of a hydrogen-bonded organic framework material (PFC-1) based on ligand 1,3,6,8-tetra(p-carboxyphenyl)pyrene;

[0115] The solvent of N,N-dimethylformamide and methanol with a volume ratio of 1:10 was configured, 10 mg of ligand 1,3,6,8-tetrakis(p-carboxyphenyl)pyrene was added, and after ultrasonic mixing, 24 μL of tetrabutylammonium hydroxide aqueous solution was added, and the solution was ultrasonically clarified. The ITO conductive glass was inserted into the solution and a voltage of 5 V was applied, and the product PFC-1 on the conductive substrate was collected multiple times until no product PFC-1 was deposited on the conductive substrate, which was recorded as the end of the first cycle; 8 mg of ligand 1,3,6,8-tetrakis(p-carboxyphenyl)pyrene was added to the solution, and after the ligand was dissolved, the above operation was repeated, and the product PFC-1 was collected multiple times until no product PFC-1 was deposited on the conductive substrate, which was recorded as the end of the second cycle; the third cycle operation was consistent with the second cycle. The ultraviolet-visible absorption spectrum of the product obtained after three cycles Figure 10 indicates that this synthesis method can be used for the continuous synthesis of HOF materials.

[0116] Example 10 Application of Hydrogen-bonded Organic Framework Thin Film Material (PFC-1) Based on the Water-phase Electro-synthesis of Example 8 in Electrochromism

[0117] A 0.1 M tetrabutylammonium hexafluorophosphate acetonitrile solution was configured and bubbled with nitrogen for 6 hours. A platinum mesh was used as a counter electrode, a silver / silver ion electrode was used as a reference electrode, and an ITO conductive glass with a PFC-1 thin film electro-synthesized in the water phase in Example 8 was used as a working electrode. Based on the above three-electrode system, a cyclic voltammogram was obtained at a scan rate of 10 mV / s, as shown in Figure 11 . In this process, it can be observed that the water-phase electro-synthesized PFC-1 thin film exhibits an electrochromic process from yellow to purple and then back to yellow.

[0118] In order to study the electrochromic performance of the water-phase electro-synthesized PFC-1 thin film, a 0.1 M tetrabutylammonium hexafluorophosphate acetonitrile solution was used as an electrolyte solution, and a voltage between 1.8 V and -0.9 V was applied (the pulse voltage cycle was 20 s), and the absorbance change at 600 nm was detected by a UV-visible spectrophotometer. The optical contrast and response time graph Figure 12 was obtained. The results show that the prepared PFC-1 thin film exhibits a coloring response time t c = 2.4 s and a bleaching response time t b = 1 s. The current and its integral curve of the electric quantity versus time curve graph Figure 13 was obtained, and the coloration efficiency (Coloration Efficiency, abbreviated as Ec or CE) was calculated according to the formula:

[0119]

[0120] where T b is the bleaching state transmittance, and T cFor the colored state transmittance, Q is the charge density in one period;

[0121] The calculated coloration efficiency (Ec) of the PFC-1 film prepared by aqueous-phase electro-synthesis is 193.5 cm 2 / C.

[0122] The above describes embodiments of the present application. However, the present application is not limited to the above-described embodiments. Any modification, equivalent replacement, improvement, and the like made within the spirit and principle of the present application should be included in the scope of the present application.

Claims

1. An electro-synthesis method for preparing a hydrogen bonded organic framework thin film material, characterized in that, The method comprises: (1) adding an organic ligand into a poor solvent or a mixed solvent of a poor solvent and a good solvent, and then adding a base to make the solution clear; (2) applying a direct current to the prepared solution with a conductive substrate as the cathode and the anode, collecting the product deposited on the conductive substrate after a period of time, and obtaining a hydrogen-bonded organic framework thin film material corresponding to the ligand.

2. The electro-synthesis method according to claim 1, characterized in that, The method further comprises the following steps: (3) after collecting the product for multiple times, without repeating the preparation of the solution, adding the corresponding organic ligand into the working solution, and repeating step (2) to realize the continuous preparation of the hydrogen-bonded organic framework thin film material.

3. The electro-synthesis method according to claim 1 or 2, characterized in that, The organic ligand in step (1) is a carboxylic acid ligand containing more than 3 COOH, whose general formula is X-[Q-(COOH) a ] b wherein; X is selected from C, N, -C=C-, unsubstituted or optionally substituted by one, two or more R1: 6-24 Aryl, 5-24 membered heteroaryl, C 6-24 Aryl-C 6-24 Aryl, 5-24 membered heteroaryl-5-24 membered heteroaryl; the 5-24 membered heteroaryl optionally forms a complex with a metal (e.g., Cu, Zn, Fe); and when X is selected from 5-24 membered heteroaryl or 5-24 heteroaryl-5-24 heteroaryl, X may be in the form of a cation; R1is selected from =0, amino, halogen or C 1-6 alkyl; Q is selected from the group consisting of a chemical bond, -C≡C-, C 6-24 aryl; a is 1 or 2; X is not C or -C=C- when Q is a chemical bond; and Y is selected from the group consisting of R2is selected from halogen or C 1-6 alkyl; a is selected from 1 or 2; b is selected from 2, 3, 4, 5 or 6; and when a is 1, b is not 2.

4. The electro-synthesis method according to any one of claims 1 to 3, characterized in that, X is selected from the group consisting of no substitution or optionally substituted by one, two or more R1: C 6-24 aryl, 5-24 membered heteroaryl, C 6-24 aryl-C 6-24 aryl, 5-24 membered heteroaryl-5-24 membered heteroaryl; the 5-24 membered heteroaryl further optionally forms a complex with a metal Cu; R1 is selected from =O, amino or Cl; Q is selected from a chemical bond, -C≡C- or C 6-20 aryl; a is selected from 1 or 2; b is selected from 2, 3 or 4; and when a is 1, b is not 2. Preferably, X is selected from C, N or -C=C-; Q is selected from C 6-24 aryl; a is selected from 1 or 2; b is selected from 1, 2, 3 or 4; and when a is 1, b is not 2.

5. The electro-synthesis method according to any one of claims 1 to 4, characterized in that, X is selected from C, -C=C-, a group unsubstituted or optionally substituted by one, two or more R1: pyrenyl, biphenyl, naphthyl, anthryl, phenyl, s-triazinyl, and when Q is a bond, X is not C or -C=C-; R1 is selected from =O, amino or Cl; Q is selected from a chemical bond, -C=C-, phenyl or naphthyl; a is selected from 1 or 2; b is selected from 2, 3 or 4; and when a is 1, b is not 2.

6. The electro-synthesis method according to any one of claims 1 to 5, characterized in that, The organic ligand is selected from the following structures:

7. The electro-synthesis method according to any one of claims 1 to 6, characterized in that, The good solvent in step (1) is selected from at least one of N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide; and the poor solvent is selected from at least one of water, methanol, ethanol, isopropanol or acetonitrile; Preferably, when the good solvent and the poor solvent are used simultaneously, the volume ratio of the good solvent to the poor solvent is 1:(3-20); Preferably, the base in step (1) is selected from at least one of sodium hydroxide, potassium hydroxide, sodium methoxide, sodium ethoxide, ammonia, aqueous tetramethylammonium hydroxide, aqueous tetraethylammonium hydroxide, aqueous tetrapropylammonium hydroxide or aqueous tetrabutylammonium hydroxide; Preferably, the molar ratio of the organic ligand to the base is 1:(1-10). Preferably, the conductive substrate in step (2) is selected from at least one of carbon paper, ITO conductive glass, FTO conductive glass, foamed copper, foamed nickel or silicon wafer; Preferably, the voltage in step (2) is not less than 3V; Preferably, the time of applying the electric current in step (2) is not less than 10s.

8. The electro-synthesis method according to any one of claims 1 to 7, characterized in that, When the organic ligand is selected from 1,3,6,8-tetra(p-carboxyphenyl)pyrene, 1,3,6,8-tetracarboxypyrene, 6,6',6",6"'-(pyrene-1,3,6,8-tetramethylphenyl) tetrakis(2-naphthalenecarboxylic acid), 1,3,5-tris(3,5-dicarboxyphenyl ethynyl) benzene or N,N'-di(5-m-phenylenediamine) naphthalene dicarboximide, the good solvent used is N,N-dimethylformamide, the poor solvent is selected from at least one of water, methanol, ethanol or acetonitrile; and the volume ratio of the good solvent to the poor solvent is 1:(10-20). Preferably, when the organic ligand is selected from 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid, the poor solvent used is selected from ethanol.

9. A hydrogen-bonded organic framework thin film material prepared by the electro-synthesis method of any one of claims 1-8.

10. Use of a hydrogen bonded organic framework thin film material produced by the electro-synthesis process of any one of claims 1-8 for the production of an electrochromic material.

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