A phenoxazine-based zirconium metal organic framework material, a preparation method and application thereof

Abstract

The application belongs to the technical field of photoelectric functional materials, and particularly relates to a zirconium metal organic framework material based on phenoxazine as well as a preparation method and application thereof. The zirconium metal organic framework material is prepared by introducing different types of dihydrophenoxazine derivative ligands, and is grown on the surface layer of FTO conductive glass based on the redox properties of the phenoxazine derivative, so as to form a metal organic framework film material. Under the condition of applying voltage to the material, electrochromism of the material can be realized, and the material has excellent application prospects in the fields of medicine, photoelectricity and the like.

Description

Technical Field

[0001] This invention belongs to the field of optoelectronic functional materials technology, specifically relating to a zirconium metal-organic framework material based on phenazine, its preparation method, and its application. Background Technology

[0002] The information disclosed in the background section of this invention is intended only to enhance the understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] Metal-organic frameworks (MOFs) have shown broad application prospects in catalysis, gas adsorption, and sensing due to their unique pore structure and tunability. In particular, the UiO-68 series of MOFs has become a research hotspot due to their excellent thermal and chemical stability.

[0004] Metal-organic frameworks (MOFs), as electrochromic materials, possess high specific surface areas, which provide more active sites and enhance electrochromic performance. They also exhibit tunable pore structures, enabling precise control of ion and molecule transport and storage, thereby optimizing the color-changing effect. However, these materials also have some drawbacks, such as relatively insufficient stability, with performance potentially declining under long-term use or complex environmental conditions. Furthermore, their synthesis processes are often complex, requiring strict control of reaction conditions and steps, which increases preparation costs and difficulty to some extent. Summary of the Invention

[0005] To address the needs of existing technologies, the purpose of this invention is to provide a phenazine-based zirconium metal-organic framework material, its preparation method, and its application. This invention introduces a phenazine carboxylic acid ligand with redox properties to coordinate and self-assemble with zirconium tetrachloride, thereby constructing a novel UiO-68 metal-organic framework material, which is then applied to the field of electrochromic materials.

[0006] Specifically, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides a phenazine-based zirconium metal-organic framework material, wherein the chemical formula of the phenazine-based zirconium metal-organic framework material is Zr6O4(OH)4L6; wherein Zr6O4(OH)4 is a hexanuclear zirconium cluster structure, and L is selected from 4,4'-(phenazine-5,10-diyl)dibenzoic acid and 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)dibenzoic acid, which are dihydrophenazine derivative ligands; the repeating structural unit of the phenazine-based zirconium metal-organic framework material is shown in Formula I:

[0008]

[0009] Preferably, in the phenazine-based zirconium metal-organic framework material, the zirconium ions are octetally coordinated, with six zirconium ions forming a hexanuclear zirconium cluster structure Zr6O4(OH)4 and the carboxylic acid oxygen coordination of the dihydrophenazine derivative ligand forming a two-dimensional layered structure.

[0010] In a second aspect, the present invention provides a method for preparing the above-mentioned phenazine-based zirconium metal-organic framework material, specifically comprising: mixing zirconium tetrachloride, 4,4'-(phenazine-5,10-diyl)dibenzoic acid, 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)dibenzoic acid and a catalyst in an organic solvent, and carrying out a solvothermal reaction to obtain the material.

[0011] Preferably, the molar ratio of zirconium tetrachloride, 4,4'-(phenazine-5,10-diyl)benzoic acid, 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)benzoic acid and the catalyst is 1:0.1-0.9:0.9-0.1:30-60; more preferably, the molar ratio of zirconium tetrachloride, 4,4'-(phenazine-5,10-diyl)benzoic acid, 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)benzoic acid and the catalyst is 1:0.5:0.5:50.

[0012] Preferably, the organic solvent is selected from one or more of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMA), 1,4-dioxane, and dimethyl sulfoxide.

[0013] Preferably, the catalyst is selected from benzoic acid and acetic acid.

[0014] Preferably, the temperature of the solvothermal reaction is 100–120°C and the time is 24–72 h.

[0015] A third aspect of the present invention provides an application of the phenazine-based zirconium metal-organic framework material described in the first aspect in electrochromic materials.

[0016] In a fourth aspect, the present invention provides an electrochromic thin film material comprising the phenazine-based zirconium metal-organic framework material described in the first aspect.

[0017] The beneficial effects achieved by one or more of the above technical solutions of the present invention are as follows:

[0018] (1) Based on the redox properties of phenazine derivatives, this invention grows them on the surface of FTO conductive glass to form a metal-organic framework film material. Under the condition of applying voltage, the material can achieve electrochromism, which has excellent application prospects in the fields of medicine and optoelectronics.

[0019] (2) Compared with metal-organic framework membrane materials prepared with single ligand components, metal-organic framework membrane materials prepared with mixed ligand components are more stable, can achieve multiple cycles of electrochromic experiments and maintain the integrity of the metal-organic framework structure. Attached Figure Description

[0020] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1 These are microscope images of the microcrystalline samples prepared in Example 1 of this invention;

[0022] Figure 2 This is a SEM image of the nanocrystals obtained by glacial acetic acid regulation prepared in Example 2 of this invention;

[0023] Figure 3 This is the powder diffraction (PXRD) pattern of UiO-68 prepared in Example 1 of this invention;

[0024] Figure 4 This is a schematic diagram of the electrochromic experiment of Embodiment 1 of the present invention;

[0025] Figure 5 This is a color change diagram of the present invention in an electrochromic experiment of MOF;

[0026] Figure 6 These are the powder diffraction (PXRD) spectra of the MOF grown on FTO conductive glass before and after the electrochromic test according to this invention.

[0027] Figure 7 This is a test graph of the cyclic stability of Embodiment 1 of the present invention in an electrochromic test;

[0028] Figure 8 This is a test graph of the cyclic stability of Comparative Example 1 of the present invention in an electrochromic test. Detailed Implementation

[0029] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] To enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.

[0031] Example 1 This embodiment provides a zirconium metal-organic framework material based on phenazine and its preparation method.

[0032] (1) Mix 9.3 mg of zirconium tetrachloride, 8.5 mg of 4,4'-(phenazine-5,10-diyl)benzoic acid and 9.5 mg of 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)benzoic acid in 1.6 mL of DMF solvent system and stir at room temperature to obtain mixture I;

[0033] (2) Add 244 mg of benzoic acid catalyst to the mixture I obtained in step (1), and then perform a solvothermal synthesis reaction at 120 °C for 24 h. After natural cooling, the product is washed with a mixed solvent of DMF and methanol, and then vacuum dried to obtain light yellow microcrystals.

[0034] Example 2 This embodiment provides a zirconium metal-organic framework material based on phenazine and its preparation method.

[0035] (1) Mix 9.3 mg of zirconium tetrachloride, 8.5 mg of 4,4'-(phenazine-5,10-diyl)benzoic acid and 9.5 mg of 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)benzoic acid in 1.6 mL of DMF solvent system and stir at room temperature to obtain mixture I;

[0036] (2) Add 120 μL of glacial acetic acid catalyst to the mixture I obtained in step (1), and then perform a solvothermal synthesis reaction at 120 °C for 24 h. After natural cooling, the product is washed with a mixed solvent of DMF and methanol, and then vacuum dried to obtain a light yellow powder.

[0037] Example 3 In this experiment, electron microscopy and scanning electron microscopy were used to observe the structural and morphological characteristics of the materials prepared in Examples 1 and 2.

[0038] like Figure 1 As shown in the electron microscope image, the material prepared in Example 1 (using benzoic acid as a catalyst) yields microcrystals with a size of 200–300 micrometers.

[0039] like Figure 2 As shown, the material prepared in Example 2 (using glacial acetic acid as a catalyst) yielded crystals with a size of 15–20 micrometers.

[0040] like Figure 3 As shown in the PXRD test pattern, the characteristic peaks of the materials prepared in Examples 1-2 appear at positions such as 4.6, 5.3, 8.8, and 9.2°, which are basically consistent with the XRD spectra of UiO-68 type MOF reported in the literature, proving that the materials prepared in Examples 1-2 of this invention have the same structure as UiO-68 type MOF.

[0041] Comparative Example 1 :

[0042] (1) Mix 9.3 mg of zirconium tetrachloride and 16.9 mg of 4,4'-(phenazine-5,10-diyl)benzoic acid in 1.6 mL of DMF solvent system and stir at room temperature to obtain mixture I;

[0043] (2) Add 244 mg of benzoic acid catalyst to the mixture I obtained in step (1), and then perform a solvothermal synthesis reaction at 120 °C for 24 h. After natural cooling, the product is washed with a mixed solvent of DMF and methanol, and then vacuum dried to obtain light yellow microcrystals.

[0044] Comparative Example 2 :

[0045] (1) Mix 9.3 mg of zirconium tetrachloride and 16.9 mg of 4,4'-(phenazine-5,10-diyl)benzoic acid in 1.6 mL of DMF solvent system and stir at room temperature to obtain mixture I;

[0046] (2) Add 120 μL of acetic acid catalyst to the mixture I obtained in step (1), and then perform a solvothermal synthesis reaction at 120 °C for 24 h. After natural cooling, the product is washed with a mixed solvent of DMF and methanol, and then vacuum dried to obtain a light yellow powder.

[0047] Application Example 1 :

[0048] In the preparation process of the phenazine-based zirconium metal-organic framework material described in Example 1 and Comparative Example 1, the FTO conductive glass was placed vertically in a reaction vessel. After the reaction was completed, FTO glass loaded with UiO-68 was obtained. Then, an electrochromic experiment was performed on it by immersing it in a phosphate electrolyte solution.

[0049] like Figure 4 The diagram shown is a flowchart of the experimental process in Example 1.

[0050] like Figure 5 The image shows photographs of the electrochromic experiment in Example 1 before and after the reaction. When a +1V voltage is applied, the color of the conductive glass changes from the original orange-yellow to green; when a -1V voltage is applied, the original color is restored.

[0051] like Figure 6 As shown, the peak positions in PXRD did not change before and after energizing, proving that the synthesized crystal structure remained unchanged.

[0052] like Figure 7As shown, after five cycles, the crystal structure prepared in Example 1 remains stable and exhibits cycle stability.

[0053] like Figure 8 As shown, after one cycle, the characteristic peaks at 4.6° and 5.3° of the crystal in Comparative Example 1 almost disappeared after one electrochromic cycle, proving that the crystal structure prepared in Comparative Example 1 had been destroyed. This indicates that the crystal prepared by the mixed ligands in Example 1 has stronger structural stability and can support multiple cycle tests.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A zirconium metal-organic framework material based on phenazine, characterized in that, The chemical formula of the phenazine-based zirconium metal-organic framework material is Zr6O4(OH)4L6; where Zr6O4(OH)4 is the hexanuclear zirconium cluster structure, and L is selected from 4,4'-(phenazine-5,10-diyl)dibenzoic acid and 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)dibenzoic acid, which are ligands of dihydrophenazine derivatives; the repeating structural unit of the phenazine-based zirconium metal-organic framework material is shown in Formula I:

2. The zirconium metal-organic framework material based on phenazine as described in claim 1, characterized in that, In the phenazine-based zirconium metal-organic framework material, the zirconium ions are octetally coordinated, with six zirconium ions forming a hexanuclear zirconium cluster structure Zr6O4(OH)4 and the carboxylic acid oxygen coordination of the dihydrophenazine derivative ligand forming a two-dimensional layered structure.

3. A method for preparing a zirconium metal-organic framework material based on phenazine according to any one of claims 1 to 2, characterized in that, Specifically, zirconium tetrachloride, 4,4'-(phenazine-5,10-diyl)dibenzoic acid, 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)dibenzoic acid and a catalyst are mixed in an organic solvent and subjected to a solvothermal reaction to obtain the product.

4. The preparation method according to claim 3, characterized in that, The molar ratio of zirconium tetrachloride, 4,4'-(phenazine-5,10-diyl)benzoic acid, 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)benzoic acid and catalyst is 1:0.1-0.9:0.9-0.1:30-60.

5. The preparation method according to claim 4, characterized in that, The molar ratio of zirconium tetrachloride, 4,4'-(phenazine-5,10-diyl)benzoic acid, 4,4'-(5,12-diazazotetraphenyl-5,12-diyl)benzoic acid and catalyst is 1:0.5:0.5:

50.

6. The preparation method according to claim 3, characterized in that, The organic solvent is selected from one or more of N,N-dimethylformamide, N,N-dimethylacetamide, 1,4-dioxane, and dimethyl sulfoxide.

7. The preparation method according to claim 3, characterized in that, The catalyst is selected from benzoic acid and acetic acid.

8. The preparation method according to claim 3, characterized in that, The solvothermal reaction is carried out at a temperature of 100–120°C for a duration of 24–72 h.

9. The application of a phenazine-based zirconium metal-organic framework material according to any one of claims 1 to 2 in electrochromic materials.

10. An electrochromic thin film material, characterized in that, Includes the zirconium metal-organic framework material based on phenazine as described in any one of claims 1 to 2.

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