Preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterial

Abstract

The application belongs to the technical field of materials, and relates to a preparation method and application of a two-dimensional metal supramolecular polymer electrochromic nanomaterial, and aims to solve the technical problems of difficulty in large-scale synthesis and paving difficulty caused by secondary transfer of a film in application of the two-dimensional metal supramolecular polymer. The two-dimensional metal supramolecular polymer electrochromic nanomaterial is prepared by adopting a one-pot reflux method, the preparation method has the advantages of simple operation, easy-to-achieve conditions and large-scale preparation, and has the advantages of easy solubility and large-area wet film construction, is suitable for construction of a uniform and porous electrochromic film, and the prepared film has the advantages of a large optical modulation range, a fast response speed, a high coloring efficiency and a long cycle life, and the film preparation process is simple, convenient, low in preparation cost, can be expanded on a large scale, and is easy to realize industrialization.

Description

Technical Field

[0001] This invention belongs to the field of materials technology and relates to a method for preparing and applying a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Background Technology

[0002] Electrochromic devices exhibit reversible and stable color changes under the influence of an applied voltage. Due to their low power consumption and adjustable color, electrochromic devices have broad application prospects, such as in cutting-edge fields like electronic tags, anti-glare rearview mirrors, and military camouflage. The performance of these devices is largely determined by the electrochromic materials used. Over the past few decades, researchers have developed various types of materials, including transition metal oxides, small organic molecules, conductive polymers, and metal-supramolecular materials. In particular, metal-supramolecular materials have attracted widespread attention due to their combination of the ease of processing and color tunability of organic materials with the stability of inorganic materials. In recent years, terpyridyl metal-supramolecular materials have been extensively studied due to their short color-changing time and high cycling stability.

[0003] In recent years, the main synthetic methods for metal-supramolecular compounds have been liquid-liquid interface methods and liquid-gas interface methods. For example, Yang Han et al. synthesized a polydentate ligand compound, 1,4-bis(2,2′:6′,2′′-terpyridin-4′-yl)benzene, and its Fe / Ru metal-supramolecular polymers, PolyFe and PolyRu. Using a Fe / Ru metal-supramolecular polymer film sprayed on ITO conductive glass as the working electrode, a 0.1 mol / L LiClO4 aqueous solution as the electrolyte, and K3Fe(CN)6 as the electrochemical complementary material, they fabricated a series of electrochromic devices. The combination of PolyFe and PolyRu yielded a colored thin film with a gradient from blue-violet (PolyFe) to orange-red (PolyRu), and multicolor electrochromic devices. The devices exhibited fast response speed (2 s), fading voltage of 0.9–1.2 V, coloring voltage of 0 V, and a maximum optical contrast of approximately 57%. The addition of K3Fe(CN)6 improved the device lifetime. However, the materials prepared in this literature are small in size and their performance needs to be improved. (Yang Han, Zhang Yuecong, Qian Yuchen, et al. Synthesis of metal-supramolecular polymers and their multicolor electrochromic devices [J]. Science in China: Chemistry, 2018, 48(7):8.). Existing technologies are limited by container volume, making it difficult to prepare large-area material films, and the films have irregular shapes. Furthermore, the adhesion between the film and the substrate after secondary transfer is weak, seriously affecting the preparation and cycling stability of large-area electrochromic devices. Therefore, developing new methods for preparing large-area electrochromic films is very important. Summary of the Invention

[0004] To address the problems of long complexation reaction times, uncontrollable thickness, and difficulties in secondary film transfer encountered in existing metal-supramolecular applications using interfacial methods, this invention proposes a method for preparing and applying two-dimensional metal supramolecular polymer electrochromic nanomaterials. This method offers advantages such as simple and convenient film preparation, low cost, scalability, and ease of industrialization. Furthermore, the prepared two-dimensional metal supramolecular polymer electrochromic nanofilms exhibit controllable thickness, uniform size over a large range, and are suitable for constructing uniform porous electrochromic films. They also possess a wide optical modulation range, fast response speed, and good cycling stability.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows: A method for preparing a two-dimensional metal supramolecular polymer electrochromic nanomaterial, comprising the following steps: S1. 2-Acetylpyridine and 4-formylphenylboronic acid were refluxed in the presence of ammonia. After the reaction was completed, the mixture was post-processed to obtain intermediate I. S2. Intermediate I obtained in step S1 and polysubstituted benzene are subjected to a Suzuki coupling reaction in tetrahydrofuran under nitrogen atmosphere. After the reaction is completed, after post-treatment, intermediate II is obtained. S3. The intermediate II obtained in step S2 is refluxed with metal ions in an organic solvent under nitrogen atmosphere. After the reaction is completed, post-treatment is performed to obtain two-dimensional metal supramolecular polymer electrochromic nanomaterials.

[0006] Furthermore, in step S1, the molar ratio of 4-formylphenylboronic acid to 2-acetylpyridine is 1:(2~5), the mass fraction of ammonia is 28%, the reflux reaction temperature is 70~80℃, and the reflux reaction time is 12~24h.

[0007] Furthermore, the concentration of 4-formylphenylboronic acid in step S1 is 0.1~2 mol / L.

[0008] Furthermore, in step S1, the molar ratio of 4-formylphenylboronic acid to 2-acetylpyridine is 1:(2~4).

[0009] Furthermore, in step S1, ammonia promotes cyclization and provides nitrogen.

[0010] Further, in step S2, the polysubstituted benzene is 1,3,5-trisubstituted benzene or 1,3-disubstituted benzene, wherein the 1,3,5-trisubstituted benzene is any one of 1,3,5-bromobenzene, 1,3,5-iodobenzene or 1,3-dibromo-5-methylbenzene; the 1,3-disubstituted benzene is 1,3-dibromobenzene; and the molar ratio of the polysubstituted benzene to intermediate I is 1:(3~5).

[0011] Furthermore, in step S2, the catalyst for the Suzuki coupling reaction is tetra(triphenylphosphine)palladium, the molar ratio of tetra(triphenylphosphine)palladium to polysubstituted benzene is (0.04~0.1):1, the temperature of the Suzuki coupling reaction is 70~80℃, and the time of the Suzuki coupling reaction is 24~72h.

[0012] Furthermore, the tetrahydrofuran system in step S2 is different from the tert-butanol and aqueous solution system. The tetrahydrofuran system can be directly filtered after the reaction to obtain a pure sample, while the tert-butanol and water system requires column purification, which is troublesome and has a low yield.

[0013] Furthermore, in step S3, the metal ion is any one of iron ions, cobalt ions, or ruthenium ions.

[0014] Preferably, the metal ion in step S3 is an iron ion.

[0015] Furthermore, the iron ions in step S3 are any one of FeCl2, Fe(OAc)2, or Fe(PF6)2.

[0016] Furthermore, in step S3, the molar ratio of intermediate II to iron ions is 1:(1~3), the organic solvent is glacial acetic acid or a mixed solution of chloroform and methanol, the volume ratio of chloroform to methanol is 1:(2~3), the reflux reaction temperature is 60~130℃, and the reflux reaction time is 6~24h.

[0017] Furthermore, the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared by the above method.

[0018] Furthermore, the application of the aforementioned two-dimensional metal supramolecular polymer electrochromic nanomaterial in two-dimensional metal supramolecular polymer electrochromic nanofilms.

[0019] Furthermore, its application steps are as follows: Y1. Dissolve the prepared two-dimensional metal supramolecular polymer electrochromic nanomaterial in a solvent to obtain an ink of the two-dimensional metal supramolecular polymer electrochromic nanomaterial. Y2. The ink of the two-dimensional metal supramolecular polymer electrochromic nanomaterial obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate by a wet film forming method.

[0020] Furthermore, in step Y1, the solvent is DMF or a low-boiling-point alcohol solvent, wherein the low-boiling-point alcohol solvent is methanol or ethanol, and the concentration of the two-dimensional metal supramolecular polymer electrochromic nanomaterial in the ink is 0.1~1 mg / mL.

[0021] Furthermore, in step Y1, when the two-dimensional metal supramolecular polymer electrochromic nanomaterial is a tridentate macromolecular coordination polymer, its solubility is low, so its concentration in the ink is 0.1~0.5 mg / mL.

[0022] Furthermore, in step Y1, when the two-dimensional metal supramolecular polymer electrochromic nanomaterial is a bidentate macromolecular coordination polymer, its solubility is good, and therefore its concentration in the ink is 0.1~1 mg / mL.

[0023] Furthermore, the wet film formation method in step Y2 is any one of spin coating, spray coating or inkjet printing, and the cleaning process is to ultrasonically clean the conductive substrate with acetone, deionized water and ethanol respectively and blow it clean with compressed air.

[0024] Furthermore, the thickness of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared by the above method is 0.2 μm to 1 μm.

[0025] Preferably, the thickness of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared by the above method is 0.3 μm to 1 μm.

[0026] The present invention has the following beneficial effects: 1. This invention employs a one-pot reflux synthesis method to prepare two-dimensional metal supramolecular polymer electrochromic nanomaterials. Specifically, 2-acetylpyridine and 4-formylphenylboronic acid are reacted under alkaline conditions to form 4-([2,2':6',2''-terpenoidyridine]-4'-yl)phenyl)boronic acid. Then, 4-([2,2':6',2''-terpenoidyridine]-4'-yl)phenyl)boronic acid is coupled with polysubstituted benzene via a Suzuki coupling reaction to obtain a multidentate terpenoid. Finally, the multidentate terpenoid is coordinated with iron ions under acidic conditions to obtain the two-dimensional metal supramolecular polymer electrochromic nanomaterials. Furthermore, uniformly porous electrochromic films are constructed on various transparent conductive substrates using a wet film-forming technique. This preparation method has the advantages of simple process, low temperature, economy, and scalability.

[0027] 2. The two-dimensional metal supramolecular polymer electrochromic nanofilm with π-π, π-d conjugation and intramolecular porous structure prepared by this invention has a thickness of 641 nm, an optical modulation range of 71.7%, a fading time of 1.5 s, a coloring time of 0.5 s, and a coloring efficiency of 1103.9 cm⁻¹. 2 C -1 In particular, the optical modulation range of the thin film remained essentially unchanged after 10,000 cycles. Based on the excellent electrochromic properties of this material, this application fabricated a large-area device (225 cm²). 2Thanks to π-π and π-d conjugation and the intramolecular porous structure that promotes ion and electron transport, large-area devices exhibit excellent electrochromic properties, such as color-changing time <20s and coloring efficiency >900cm². 2 C -1 The two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared by this invention can not only be used in the field of electrochromism, but also in energy storage, photoelectrocatalysis and other fields to construct electrochromic display devices, and have broad application prospects. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a flowchart illustrating the preparation process of the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in Example 1 of the present invention.

[0030] Figure 2 This is a flowchart illustrating the preparation process of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared in Example 1 of the present invention.

[0031] Figure 3 The figures show the characterization results of the composition, structure, and morphology of the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in Example 1 of this invention. In the figures, a is the visible light spectrum of intermediate II and the nanomaterial; b-d are the XPS spectra of the nanomaterial; e is the AFM schematic diagram of the nanomaterial; and f is the SEM schematic diagram of the nanomaterial.

[0032] Figure 4 This image shows the electrochromic performance of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared in Example 1 of this invention. In the image, a represents the electrochromic performance of the electrochromic film of Example 1 at 20 mV s. -1 a) Cyclic voltammetry curves; b) Transmittance of the electrochromic film of Example 1 as a function of applied potential; c) Transmittance of the electrochromic film of Example 1 at 576 nm as a function of square wave potential; d) Optical density of the electrochromic film of Example 1 at 576 nm as a function of charge density; e) Optical density of the electrochromic film of Example 1 at 576 nm wavelength, 0.4V - 1.4V. vs. Ag + Changes in transmittance over 10,000 cycles under / Ag.

[0033] Figure 5This is the electrochemical kinetic spectrum of the two-dimensional metal supramolecular polymer electrochromic nanofilm of Example 1 of the present invention. Wherein, a represents the electrochemical kinetics of the LiClO4 / PMMA gel electrolyte at 5~600 mV s⁻¹. -1 a) Cyclic voltammetry curve of the electrochromic thin film of Example 1; b) Peak oxidation and reduction current of the electrochromic thin film of Example 1 as a function of scan rate; c) Capacitive contribution of the electrochromic thin film of Example 1 at 50 mV s⁻¹; d) Capacitive contribution of the electrochromic thin film of Example 1 in the range of 10~50 mV s⁻¹. -1 The capacitance and diffusion contribution.

[0034] Figure 6 This is an electrochemical energy storage spectrum of a two-dimensional metal supramolecular polymer electrochromic nanofilm according to an embodiment of the present invention. In the spectrum, a represents the constant current charge-discharge curves of the electrochromic film of Example 1 at different current densities; b and c represent the electrochromic film of Example 1 at 0.2 A g... -1 and 3.0A g -1 The constant current charge-discharge curves and the corresponding in-situ transmittance changes at 576 nm; d represents the relationship between the mass capacitance and optical modulation range of the electrochromic film in Example 1 and the current density.

[0035] Figure 7 This is a large-area electrochromic device assembled from the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared in Example 1 of this invention. In the figures, a is a schematic diagram of the semi-solid-state device structure; b and c are optical photographs of the device in its colored and faded states, respectively; d shows the transmittance at three different points on the device as a function of wavelength; e shows the transmittance at 576 nm as a function of time; and f is a graph showing the relationship between optical density and charge.

[0036] Figure 8 This is an SEM cross-sectional image of the electrochromic film prepared by electrostatic spraying technology from the two-dimensional metal supramolecular polymer electrochromic nanomaterial of Example 2 of the present invention. ae represents the SEM cross-section of the film at different spraying times, and f is a graph showing the relationship between spraying time and film thickness.

[0037] Figure 9 This invention provides the electrochromic properties of two-dimensional metal supramolecular polymer electrochromic nanofilms prepared at different thicknesses in Example 2 of the present invention.

[0038] Figure 10This invention presents a schematic diagram and results of the preparation of a two-dimensional metal supramolecular polymer electrochromic nanofilm using the electrostatic spraying technology. In the diagram, a is an optical photograph of the ink containing the two-dimensional metal supramolecular polymer electrochromic nanomaterial at a concentration of 0.3 mg / mL; b is a schematic diagram of the electrostatic spraying process; c is an optical photograph of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared by electrostatic spraying; d is an optical transmittance spectrum of the two-dimensional metal supramolecular polymer electrochromic nanofilm; e is a demonstration of a large-area flexible film prepared by electrostatic spraying; and f is an optical photograph of the large-area flexible film in a bent state. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] All raw materials used in this invention are commercially available products.

[0041] Example 1 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 5.3 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 °C for 20 h. After the solution is cooled to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). White powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid) 1H NMR (300MHz, CD3OD, 300 K, δ, ppm): 8.68 (d, J = 4.7 Hz, 2H), 8.64 (s, 2H), 8.61 (d, J =8.0 Hz, 2H), 7.98 (t, J = 7.8 Hz, 2H), 7.76 (s, 4H), 7.53 - 7.40 (m, 2H); 13 C NMR (75MHz, CDCl3, 300 K, δ, ppm): δ157.6, 157.0, 150.0, 138.8, 135.2, 125.3, 123.0, 119.6; ESI-MS (m / z): Calcd. for [C 21 H 16 BN3O2+H] + Found: 354.13; S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3,5-tribromobenzene via a Suzuki coupling reaction to obtain tridentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1 M Na2CO3 aqueous solution. Then, 315 mg of 1,3,5-tribromobenzene, 1.74 g of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 116 mg of tetra(triphenylphosphine)palladium are added to a 500 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 30 mL of 1 M Na2CO3 aqueous solution and 210 mL of tetrahydrofuran are added. The above solution is reacted at 75 °C for 48 h. The solution was cooled to room temperature, filtered, washed, and dried to give a white powder intermediate II (1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene). White powder intermediate II (1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene) 1 H NMR (400 MHz, CDCl3, 300 K, δ, ppm): 8.84 (s, 6H), 8.77 (d, J = 4.4 Hz, 6H), 8.71 (d, J =7.9 Hz, 6H), 8.09 (d, J = 8.2 Hz, 6H), 7.97 (s, 3H), 7.95-7.86 (m, 12H), 7.38 (dd, J = 6.9, 5.2 Hz, 6H); 13C NMR (125 MHz, CDCl3, 300 K, δ, ppm): δ 156.2, 155.9, 149.0, 141.8, 141.5, 137.6, 136.8, 127.8, 125.3, 123.7, 121.3, 118.7; ESI-TOF (m / z): Calcd. for[C 69 H 45 N9+H] + :1000.38, Found: 1000.38; S3. The 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene obtained in step S2 was reacted with ferrous acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 100 mg of 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene and 30 mg of Fe(OAc)₂ were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of glacial acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 24 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a dark purple solid.

[0042] It is worth noting that, in this embodiment, the preparation of "gram-level" metal supramolecular materials by one-step reflux method is beneficial for the subsequent large-scale fabrication of thin films and large-area devices.

[0043] Figure 3 The figures show the characterization results of the composition, structure, and morphology of the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in this embodiment. In the figures, a represents the visible light spectrum of intermediate II and the nanomaterial, bd represents the XPS spectrum of the nanomaterial, e represents the AFM schematic diagram of the nanomaterial, and f represents the SEM schematic diagram of the nanomaterial. Figure 3 As shown in Figure a, to verify the successful synthesis of two-dimensional metal supramolecular polymer electrochromic nanomaterials, we measured the UV-Vis spectra of intermediate II ligand tridentate terpyridine and the complexed material, respectively. The UV-Vis spectrum of the ligand in dichloromethane solution showed a strong absorption band between 260-340 nm, corresponding to the characteristic π-π* transition. Furthermore, a new absorption peak was observed at 576 nm in the complexed material, a typical MLCT absorption peak, due to the transfer of electrons from the Fe(d) HOMO to the LUMO π* orbital. Figure 3As shown in b-3d, we further tested the X-ray photoelectron spectroscopy (XPS) of the two-dimensional metal supramolecular polymer electrochromic nanofilm, revealing resonance peaks for Fe, N, C, and O. Integrating the Fe and N resonance peaks, we calculated the N / Fe elemental ratio to be 5.9, which is in excellent agreement with the theoretical result (Fe / N = 1:6). The high-resolution XPS spectra in the Fe (2p) and N (1s) regions are shown below. Figure 3 As shown in c and 3d, the high-resolution N 1s spectrum can be divided into three sub-peaks, corresponding to pyridine N (398.7 eV), the N-Fe bond of the two-dimensional metal supramolecular polymer (399.9 eV), and N oxide (405.8 eV), respectively. The high-resolution Fe 2p spectrum shows that 708.8 eV and 721.4 eV are the Fe 2p3 / 2 and Fe 2p1 / 2 peaks, respectively, and 711.1 eV and 724.5 eV correspond to the Fe 2p3 / 2 and Fe 2p1 / 2 satellite peaks, respectively. The above absorption spectra and XPS spectra indicate that we have successfully prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials. To determine the original morphology of the two-dimensional metal supramolecular polymer electrochromic nanomaterials, two-dimensional metal supramolecular polymer electrochromic nanofilms were prepared by spin coating, and their original morphology was observed using atomic force microscopy (AFM) and scanning electron microscopy (SEM). Figure 3 As shown in Figure e, the film exhibits typical two-dimensional nanosheets with a diameter of approximately 200–300 nm and a thickness of approximately 7 nm, likely composed of aggregated nanoparticles. Figure 3 As shown in f, the SEM images also show that the microstructure of MSP-Fe is nanoparticles, which is in good agreement with the AFM results.

[0044] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare two-dimensional metal supramolecular polymer electrochromic nanofilms, such as... Figure 2 As shown, the preparation of two-dimensional metal supramolecular polymer electrochromic nanofilms includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted to 0.3 mg / mL using a mixed solvent of DMF and ethanol to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 0.8 mL / h. Secondly, the FTO conductive glass is ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min each, and then blown clean with nitrogen gas to obtain a clean FTO conductive glass. Thirdly, the distance between the metal needle and the FTO conductive glass is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the FTO conductive glass. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the FTO conductive glass in a molecular state. Finally, the spraying area is set to 2.5 × 10 cm. 2 The spraying time was set to 5 hours. After the spraying was completed, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of about 0.64 μm was obtained.

[0045] Figure 4 This is a graph showing the electrochromic properties of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared in this embodiment. In the graph, a represents the electrochromic film of Example 1 at 20 mV st. -1 The cyclic voltammetry curves are shown below. b represents the transmittance of the electrochromic film of Example 1 as a function of applied potential; c represents the transmittance of the electrochromic film of Example 1 at 576 nm as a function of square wave potential; d represents the optical density of the electrochromic film of Example 1 at 576 nm as a function of charge density; and e represents the optical density of the electrochromic film of Example 1 at 576 nm wavelength, from 0.4V to 1.4V. vs. Ag + Changes in transmittance over 10,000 cycles under / Ag. For example... Figure 4 As shown, to study the electrochromic properties of the two-dimensional metal supramolecular polymer electrochromic nanofilm in this embodiment, LiClO4-PMMA-based gel was used as the electrolyte, the two-dimensional metal supramolecular polymer electrochromic nanofilm was used as the working electrode, platinum wire was used as the counter electrode, and silver wire was used as the reference electrode. Figure 4 As shown in a, at 20mV s -1 Cyclic voltammetry tests were performed on the thin film at 0-1.5V. vs Ag + There are obvious redox peaks under / Ag, which are attributed to the redox behavior of Fe(II) / Fe(III). Specifically, when the applied potential is from 0V... vs Ag + / Ag increased to 1.5V vs Ag +At / Ag, the film color slowly changes from purple to yellow. Cyclic voltammetry curves at 1.1V... vs Ag + An oxidation peak appeared at / Ag, which is attributed to LMCT. However, when the applied potential was increased from 1.5V... vs Ag + / Ag decreases to 0V vs Ag + When / Ag is applied, the film color reverts to purple. Thanks to its unique molecular π-π and π-d conjugated structure and intramolecular pores, the cyclic voltammetric curves of the two-dimensional metal supramolecular polymer electrochromic nanofilm exhibit slight electrochemical polarization and good symmetry, implying good stability. For example... Figure 4 As shown in b, to systematically study the dependence of transmittance on applied potential, we investigated the range from 0.4 to 1.5 V. vs Ag + The UV-Vis transmission spectra of Ag at different potentials. Initially, the film is purple with a transmittance of 19% at 576 nm. When the applied potential is 1.5V... vs Ag + When the film is in Ag, the transmittance at 576 nm increases significantly to 90.7%. To accurately verify the reversibility of the film, we applied 0.4V. vs Ag + The transmittance curve for the / Ag potential is consistent with that of the initial state. When we further increase the potential, we find that the transmittance gradually increases with increasing potential. It is noteworthy that the film at 1.3V... vs Ag + At a potential of / Ag, it reverts to yellow, and its transmittance curve is similar to that at 1.5V. vs Ag + The transmittance curves under the / Ag potential are consistent, indicating that the film has excellent reversibility. For example... Figure 4 As shown in Figure c, to evaluate the color-changing time of the two-dimensional metal supramolecular polymer electrochromic nanofilm, we applied voltages of 0.4 and 1.4 V to the film. vs Ag + The transmittance spectrum of the two-dimensional metal supramolecular polymer electrochromic nanofilm was monitored in situ at 576 nm at a square wave potential between / Ag. The nanofilm not only possessed a 71.7% optical modulation range, but also exhibited fading and coloring times of 1.5 s and 0.5 s, respectively. This ultrafast switching time is attributed to the intramolecular π-π and π-d conjugated structure, which facilitates electron transport, while the intramolecular pores facilitate electrolyte permeation. The coloring efficiency, calculated from the kinetic spectrum, reached a high value of 1103.9 cm⁻¹. 2 C -1 ( Figure 4 d). Based on the electrochromic mechanism, fewer ion insertions and extractions result in a larger optical modulation range, which is beneficial to the material's lifespan. For example... Figure 4 As shown in Figure e, to evaluate the lifetime of the two-dimensional metal supramolecular polymer electrochromic nanofilm, we continuously applied voltages of 0.4 and 1.4 V to the film. vs Ag + The dynamic change of the transmittance spectrum of the in-situ detector at 576 nm using the / Ag square wave potential was observed. After more than 10,000 cycles, the light modulation retention rate of the two-dimensional metal supramolecular polymer electrochromic nanofilm was greater than 97%, verifying its excellent and robust electrochemical stability. During cycling, the film did not dissolve or detach, which is attributed to the strong adhesion between the film and the substrate. Therefore, in addition to its rapid switching time and ultra-high coloring efficiency, the two-dimensional metal supramolecular polymer electrochromic nanofilm exhibits long-term cycling stability.

[0046] Figure 5 This is the electrochemical kinetic spectrum of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared in this embodiment. Where a represents the electrochemical kinetic spectrum in LiClO4 / PMMA gel electrolyte, 5–600 mV s⁻¹. -1 At that time, the cyclic voltammetry curves of the electrochromic thin film of Example 1 are shown in Figure 1. Figure 2 shows the peak oxidation and reduction currents of the electrochromic thin film of Example 1 as a function of scan rate. Figure 3 shows the capacitance contribution of the electrochromic thin film of Example 1 at 50 mV s⁻¹. Figure 4 shows the capacitance contribution of the electrochromic thin film of Example 1 at 10~50 mV s⁻¹. -1 The capacitance and diffusion contribution. For example... Figure 5 As shown in figure a, inspired by the ultra-high coloring efficiency and excellent stability of the two-dimensional metal supramolecular polymer electrochromic nanofilms prepared by electrostatic spraying technology, we further developed a method based on 5~600mV s -1 Cyclic voltammetry curves were used to further explore the electrochemical reaction kinetics. With increasing scan rate, the peak spacing of the redox pairs changed little, but the current density increased sharply with increasing scan rate, while the redox peaks remained well maintained, even at 600 mV s⁻¹. -1 The film maintains good redox peak shape even at high scan rates, indicating rapid charge transfer and low internal resistance within the film. Furthermore, the symmetrical redox peaks verify the excellent reversibility of the two-dimensional metal supramolecular polymer electrochromic nanofilm. The coverage area and peak current of the redox peaks are essentially the same at different scan rates, confirming the excellent and stable electrochemical stability of the two-dimensional metal supramolecular polymer electrochromic nanofilm. This can be achieved according to equation Log( i =b log( v The reaction kinetics were analyzed using log(a) + log(a), and the reaction was analyzed from log(a) + ... i) and log ( v The peak values ​​of the anode and cathode currents calculated from the curves are both 0.72 (b-values). Figure 5 (b) This value indicates that the reaction is jointly controlled by pseudocapacitance and diffusion. To further confirm the contributions of capacitance and diffusion in the electrochemical reaction, the equation was determined... i =k1 v + k2 v 1 / 2 By determining constants k1 and k2, the capacitor control current (k1) at a specific potential can be obtained. v ) and diffusion control current (k2) v 1 / 2 This allows us to obtain the capacitance contribution rate at each scan rate. (At 50mV / s) -1 At the scan rate, capacitance contributes 75.9% of the total current. Figure 5 c). Among the three electrodes, the capacitance contribution rate increases slightly with increasing scan rate, which is attributed to the increased capacitance process at high scan rates. Figure 5 d).

[0047] Figure 6 The image shows the electrochemical energy storage spectrum of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared in this embodiment. a represents the constant current charge-discharge curves of the electrochromic film of Example 1 at different current densities; b and c represent the electrochromic film of Example 1 at 0.2 A g... -1 and 3.0A g -1 The constant current charge-discharge curves and the corresponding in-situ transmittance changes at 576 nm are shown. d represents the relationship between the mass capacitance and optical modulation range of the electrochromic thin film in Example 1 and the current density. Figure 6 As shown, to quantitatively analyze its energy storage performance, constant current charge-discharge curves were used in the range of 0.4-1.2V. vs Ag / Ag + Tests are performed under charging / discharging conditions. For example... Figure 6 As shown in Figure a, the current densities are 0.2, 0.3, 0.9, 1.2, and 3 A. -1 The galvanostatic charge-discharge curves of the two-dimensional metal supramolecular polymer electrochromic nanofilm exhibit an approximately symmetrical shape with smooth plateaus, corresponding to the Fe(II) / Fe(III) redox couple. Furthermore, the negligible IR drop and nearly symmetrical charge-discharge curves indicate that the two-dimensional metal supramolecular polymer electrochromic nanofilm possesses rapid charge transport capabilities. The film was tested at currents of 0.2, 0.3, 0.9, 1.2, and 3.0 Ag. -1 At the given current densities, the mass capacitances were 12.01, 10.99, 10.87, 10.18, and 10.08 mAh g, respectively. -1These results indicate that intramolecular redox conduction and the accompanying anti-anion transfer are relatively rapid, enabling fast charging and discharging processes. The better rate performance of the two-dimensional metal supramolecular polymer electrochromic nanofilms can be attributed to increased conductivity and porous structure, which accelerates electron transfer and electrolyte diffusion. Considering that the electrochromic and energy storage processes of the two-dimensional metal supramolecular polymer electrochromic nanofilms occur in the same electrolytic cell, integrating these two functions into a single system is very attractive. Figure 6 As shown in b and 6c, to demonstrate this promising concept, we measured the dynamic changes in in-situ transmittance at 576 nm during galvanostatic charge-discharge at different current densities. The two-dimensional metal supramolecular polymer electrochromic nanofilm experienced a color change from purple to pale yellow during charging. During discharging, the two-dimensional metal supramolecular polymer electrochromic nanofilm returned to its initial state. There is a one-to-one correspondence between the energy storage level and transmittance. Therefore, the energy storage level of the two-dimensional metal supramolecular polymer electrochromic nanofilm can be estimated by observing the obvious color change. Figure 6 As shown in d, it is noteworthy that sufficient color switching can be observed even at high current densities. When a current density of 0.2~3.0 A g is applied... -1 At that time, the optical modulation remained essentially unchanged. These results further validate the excellent rate performance and excellent charge carrier transport capability of the two-dimensional metal supramolecular polymer electrochromic nanofilm under high current charge and discharge conditions.

[0048] Figure 7 This is a large-area electrochromic device assembled from the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared in this embodiment. A is a schematic diagram of the semi-solid-state device structure; b and c are optical photographs of the device in the colored and faded states, respectively; d shows the transmittance of the device at three different points as a function of wavelength; e shows the transmittance at 576 nm as a function of time; and f is a graph showing the relationship between optical density and charge. Figure 7 As shown, large-area devices are of significant value in electronic displays such as e-books and electronic billboards. Display devices should simultaneously achieve short switching times and uniform color changes over a large area. However, due to the internal resistance of the electrodes, voltage drops exist between different areas of large-area devices. Therefore, a major challenge is achieving uniform coloring and fading on large-area devices. Considering that two-dimensional metal supramolecular polymer electrochromic nanofilms possess both a large optical modulation range and a short color-changing time, we assembled a large-area device (225 cm⁻¹). 2 And evaluate its color-changing performance. At a scan rate of 20 mV / s... -1At this point, the cyclic voltammetry curve of the device showed a distinct redox peak between -1.2V and 3V. When the applied voltage increased above 2.4V, the device turned yellow, mainly due to the LMCT reaction of the two-dimensional metal supramolecular. However, when the applied voltage was below -0.7V, LMCT re-occurred, causing the device to revert to its purple color. To characterize the uniformity of coloring and fading, we tested the electrochromic performance at three different points from the center to the edge. Thanks to π-π and π-d conjugation and the intramolecular porous structure promoting ion and electron transport, the large-area device exhibited ideal electrochromic performance, such as a greater than 50% optical modulation range and a coloring efficiency greater than 960 cm⁻¹. 2 C -1 The fading time is less than 20 seconds, and the coloring time is less than 3 seconds.

[0049] Example 2 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 5.3 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 °C for 20 h. After the solution is cooled to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3,5-tribromobenzene via a Suzuki coupling reaction to obtain tridentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1M Na2CO3 aqueous solution. Then, 315 mg of 1,3,5-tribromobenzene, 1.74 g of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 116 mg of tetra(triphenylphosphine)palladium are added to a 500 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 30 mL of 1M Na2CO3 aqueous solution and 210 mL of tetrahydrofuran are added. The above solution is reacted at 75 °C for 48 h. The solution was cooled to room temperature, filtered, washed, and dried to give a white powder intermediate II (1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene). Step S3: The 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene obtained in step S2 was reacted with ferrous acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 100 mg of 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene and 30 mg of Fe(OAc)₂ were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of glacial acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 24 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a dark purple solid.

[0050] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted to 0.3 mg / mL using a mixed solvent of DMF and ethanol to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 0.8 mL / h. Secondly, the FTO conductive glass is ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min each, and then blown clean with nitrogen gas to obtain a clean FTO conductive glass. Thirdly, the distance between the metal needle and the FTO conductive glass is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the FTO conductive glass. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the FTO conductive glass in a molecular state. Finally, the spraying area is set to 2.5 × 5 cm. 2 The spraying time was set to 1.5h, 2.0h, 2.5h, 3.0h, and 3.5h. After spraying, uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilms with thicknesses of 362 nm, 445 nm, 641 nm, 704 nm, and 819 nm were obtained.

[0051] In this embodiment, UV-Vis absorption spectroscopy and X-ray diffraction analysis showed that the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in this embodiment were consistent with the results of Example 1. The results of SEM and AFM observations of the two-dimensional metal supramolecular polymer electrochromic nanomaterials in this embodiment were also similar to those in Example 1. The spectral changes and electrochromic response speed of the two-dimensional metal supramolecular polymer electrochromic nanofilm in this embodiment were tested using an electrochemical workstation and spectrophotometer.

[0052] Figure 8 This is an SEM cross-sectional image of the electrochromic film prepared from the two-dimensional metal supramolecular polymer electrochromic nanomaterial using electrostatic spraying technology in this embodiment. ae represents the SEM cross-section of the film at different spraying times, and f is a graph showing the relationship between spraying time and film thickness. It illustrates that the film thickness increases linearly with increasing spraying time.

[0053] Figure 9 This example illustrates the electrochromic properties of two-dimensional metal supramolecular polymer electrochromic nanofilms prepared at different thicknesses. Figure 8 and Figure 9 As shown, the optical modulation range and color-changing time of the two-dimensional metal supramolecular polymer electrochromic nanofilm both increase with the increase of the two-dimensional metal supramolecular polymer electrochromic nanofilm, while the coloring efficiency decreases with the increase of the two-dimensional metal supramolecular polymer electrochromic nanofilm.

[0054] Example 3 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 5.3 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 ℃ for 20 h. After the solution cools to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3,5-tribromobenzene via a Suzuki coupling reaction to obtain tridentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1 M Na2CO3 aqueous solution. Then, 315 mg of 1,3,5-tribromobenzene, 1.74 g of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 116 mg of tetra(triphenylphosphine)palladium are added to a 500 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 30 mL of 1 M Na2CO3 aqueous solution and 210 mL of tetrahydrofuran are added. The above solution is reacted at 75 °C for 48 h. The solution was cooled to room temperature, filtered, washed, and dried to give a white powder intermediate II (1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene). Step S3: The 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene obtained in step S2 was reacted with ferrous acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 100 mg of 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene and 30 mg of Fe(OAc)₂ were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of glacial acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 24 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a dark purple solid.

[0055] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted to 0.3 mg / mL using a mixed solvent of DMF and ethanol to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 0.8 mL / h. Secondly, the ITO / PET substrate is ultrasonically cleaned for 15 min each with acetone, deionized water, and ethanol, and then purged with nitrogen gas to obtain a clean ITO / PET substrate. Thirdly, the distance between the metal needle and the ITO / PET substrate is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the ITO / PET substrate. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the ITO / PET substrate in a molecular state. Finally, the spraying area is set to 25 × 30 cm. 2 The spraying time was set to 24 hours. After the spraying was completed, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of about 0.4 μm was obtained.

[0056] In this embodiment, UV-Vis absorption spectroscopy and X-ray diffraction analysis showed that the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in this embodiment were consistent with the results of Example 1. The results of SEM and AFM observations of the two-dimensional metal supramolecular polymer electrochromic nanomaterials in this embodiment were also similar to those in Example 1. The spectral changes and electrochromic response speed of the two-dimensional metal supramolecular polymer electrochromic nanofilm in this embodiment were tested using an electrochemical workstation and spectrophotometer. This indicates that the two-dimensional metal supramolecular polymer electrochromic nanofilm has the advantages of a large optical modulation range, fast response speed, and good cycling performance.

[0057] Figure 10Optical photographs of the electrochromic films prepared on large-size FTO and ITO / PET substrates using electrostatic spraying technology for the two-dimensional metal supramolecular polymer electrochromic nanomaterials of this embodiment are shown. In the images, a is an optical photograph of the ink containing the two-dimensional metal supramolecular polymer electrochromic nanomaterials at a concentration of 0.3 mg / mL; b is a schematic diagram of the electrostatic spraying process; c is an optical photograph of the two-dimensional metal supramolecular polymer electrochromic nanofilm prepared by electrostatic spraying; d is the optical transmittance spectrum of the two-dimensional metal supramolecular polymer electrochromic nanofilm; e is a demonstration of the large-area flexible film prepared by electrostatic spraying; and f is an optical photograph of the large-area flexible film in a bent state. The prepared large-size two-dimensional metal supramolecular polymer electrochromic film exhibits good uniformity. Furthermore, due to the electrostatic force, the film maintains good contact with the substrate, and no detachment occurs when bent at 180°.

[0058] Example 4 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 5.3 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 °C for 20 h. After the solution is cooled to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3,5-triiodobenzene via a Suzuki coupling reaction to obtain tridentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1 M Na2CO3 aqueous solution. Then, 315 mg of 1,3,5-triiodobenzene, 1.74 g of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 116 mg of tetra(triphenylphosphine)palladium are added to a 500 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 30 mL of 1 M Na2CO3 aqueous solution and 210 mL of tetrahydrofuran are added. The above solution is reacted at 75 °C for 48 h. The solution was cooled to room temperature, filtered, washed, and dried to give a white powder intermediate II (1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene). Step S3: The 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene obtained in step S2 was reacted with ferrous acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 100 mg of 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene and 30 mg of Fe(OAc)₂ were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of glacial acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 24 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a dark purple solid.

[0059] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted to 0.3 mg / mL using a mixed solvent of DMF and ethanol to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 0.8 mL / h. Secondly, the FTO conductive glass is ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min each, and then blown clean with nitrogen gas to obtain a clean FTO conductive glass. Thirdly, the distance between the metal needle and the FTO conductive glass is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the FTO conductive glass. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the FTO conductive glass in a molecular state. Finally, the spraying area is set to 2.5 × 10 cm. 2 The spraying time was set to 5 hours. After the spraying was completed, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of about 0.55 μm was obtained.

[0060] In this embodiment, UV-Vis absorption spectroscopy and X-ray diffraction analysis showed that the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in this embodiment were consistent with the results of Example 1. The results of SEM and AFM observations of the two-dimensional metal supramolecular polymer electrochromic nanomaterials in this embodiment were also similar to those in Example 1. The spectral changes and electrochromic response speed of the two-dimensional metal supramolecular polymer electrochromic nanofilm in this embodiment were tested using an electrochemical workstation and spectrophotometer. This indicates that the two-dimensional metal supramolecular polymer electrochromic nanofilm has the advantages of a large optical modulation range, fast response speed, and good cycling performance.

[0061] Example 5 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 5.3 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 °C for 20 h. After the solution cools to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). White powder intermediate I 1 H NMR (300 MHz, CD3OD, 300 K, δ, ppm): 8.68 (d, J = 4.7Hz, 2H), 8.64 (s, 2H), 8.61 (d, J = 8.0 Hz, 2H), 7.98 (t, J = 7.8 Hz, 2H), 7.76 (s, 4H), 7.53 - 7.40 (m, 2H); 13 C NMR (75 MHz, CDCl3, 300 K, δ, ppm): δ157.6, 157.0, 150.0, 138.8, 135.2, 125.3, 123.0, 119.6; ESI-MS (m / z): Calcd. for [C 21 H 16 BN3O2+H] + Found: 354.13. Found: 353.45; S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3,5-tribromobenzene via a Suzuki coupling reaction to obtain a bidentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1M Na2CO3 aqueous solution. Then, 157 mg of 1,3,5-tribromobenzene, 531 mg of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 30 mg of tetra(triphenylphosphine)palladium are added to a 100 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 5 mL of 1M Na2CO3 aqueous solution and 30 mL of tetrahydrofuran are added. The above solution is reacted at 75 °C for 48 h. The solution was cooled to room temperature, filtered, washed, and dried to give a white powder intermediate II (4',4''''-(5'-bromo-[1,1':3',1''-terphenyl]-4,4''-diyl)bis-2,2':6',2''-terpyridine). White powder intermediate II 1 H NMR (400 MHz, CDCl3, 300 K, δ, ppm): 8.82 (s, 4H), 8.76 (dt, J = 4.6, 1.4 Hz, 4H), 8.70 (dt, J = 8.1, 1.1 Hz, 4H), 8.08 – 8.02 (m, 4H), 7.91 (td, J = 7.7, 1.8 Hz, 5H), 7.86 (t, J= 1.6 Hz, 1H), 7.84 – 7.77 (m, 6H), 7.38 (ddd, J = 7.5, 4.8, 1.2 Hz, 4H); 13 C NMR (125 MHz, CDCl3, 300 K, δ, ppm): 155.1, 155.0, 148.5, 148.1, 142.0, 139.2, 137.1, 135.9, 128.2, 126.9, 126.7, 123.7, 122.8, 122.4, 120.3, 117.7; ESI-TOF (m / z): Calcd. for [C 69 H 45 N9 + H] + Found: 771.18; Step S3: The 4',4''''-(5'-bromo-[1,1':3',1''-terphenyl]-4,4''-diyl)bis-2,2':6',2''-terpyridine obtained in step S2 was reacted with ferrous acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 154 mg of 4',4''''-(5'-bromo-[1,1':3',1''-terphenyl]-4,4''-diyl)bis-2,2':6',2''-terpyridine and 35 mg of Fe(OAc)2 were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of glacial acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 24 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a dark purple solid.

[0062] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted with methanol solvent to 1 mg / mL to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 1 mL / h. Secondly, the FTO conductive glass is ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min each, and then blown clean with nitrogen gas to obtain a clean FTO conductive glass. Thirdly, the distance between the metal needle and the FTO conductive glass is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the FTO conductive glass. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the FTO conductive glass in a molecular state. Finally, the spraying area is set to 2.5 × 20 cm. 2 The spraying time was set to 1 hour, and after spraying, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of about 0.55 μm was obtained.

[0063] In this embodiment, UV-Vis absorption spectroscopy and X-ray diffraction analysis showed that the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in this embodiment were consistent with the results of Example 1. The results of SEM and AFM observations of the two-dimensional metal supramolecular polymer electrochromic nanomaterials in this embodiment were also similar to those in Example 1. The spectral changes and electrochromic response speed of the two-dimensional metal supramolecular polymer electrochromic nanofilm in this embodiment were tested using an electrochemical workstation and spectrophotometer. This indicates that the two-dimensional metal supramolecular polymer electrochromic nanofilm has the advantages of a large optical modulation range, fast response speed, and good cycling performance.

[0064] Example 6 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 5.3 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 °C for 20 h. After the solution is cooled to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). White powder intermediate I 1 H NMR (300 MHz, CD3OD, 300 K, δ, ppm): 8.68 (d, J = 4.7Hz, 2H), 8.64 (s, 2H), 8.61 (d, J = 8.0 Hz, 2H), 7.98 (t, J = 7.8 Hz, 2H), 7.76 (s, 4H), 7.53 - 7.40 (m, 2H); 13 C NMR (75 MHz, CDCl3, 300 K, δ, ppm): δ157.6, 157.0, 150.0, 138.8, 135.2, 125.3, 123.0, 119.6; ESI-MS (m / z): Calcd. for [C 21 H 16 BN3O2+H] + Found: 354.13; S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3-dibromobenzene via a Suzuki coupling reaction to obtain bidentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1M Na2CO3 aqueous solution. Then, 118 mg of 1,3-dibromobenzene, 531 mg of 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 29 mg of tetra(triphenylphosphine)palladium are added to a 100 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 5 mL of 1M Na2CO3 aqueous solution and 30 mL of tetrahydrofuran are added. The above solution is reacted at 75 °C for 48 h. The solution was cooled to room temperature, filtered, washed, and dried to give a white powder intermediate II (4,4''-bis([2,2':6',2''-terpyridine]-4'-yl)-1,1':3',1''-terphenyl). White powder intermediate II 1 H NMR (400 MHz, CDCl3, 400 K, δ, ppm): δ 8.82 (s, 4H), 8.76 (ddd, J = 4.8, 1.8, 0.9 Hz, 4H), 8.70 (dt, J = 8.0, 1.1 Hz, 4H), 8.09 – 8.02 (m, 4H), 7.96 (t, J = 1.8 Hz, 1H), 7.90 (td, J= 7.7, 1.8 Hz, 4H), 7.86 – 7.80 (m, 4H), 7.70 (dd, J = 7.3, 1.8 Hz, 2H), 7.60 (dd, J = 8.4, 6.9 Hz, 1H), 7.37 (ddd, J =7.5, 4.8, 1.2 Hz, 4H); 13 C NMR (100 MHz, CDCl3, 300 K, δ, ppm): δ 156.2, 156.0, 149.7, 149.1, 141.7, 141.1, 137.5, 136.8, 129.4, 127.8, 127.7, 126.4, 126.0, 123.8, 121.4, 118.7; ESI-TOF (m / z): Calcd. for [C 48 H 32 N6 + H] + Found: 693.28; Step S3: The 4,4''-bis([2,2':6',2''-terpyridine]-4'-yl)-1,1':3',1''-terphenyl obtained in step S2 was reacted with ferrous acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 118 mg of 4,4''-bis([2,2':6',2''-terpyridine]-4'-yl)-1,1':3',1''-terphenyl and 35 mg of Fe(OAc)2 were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of glacial acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 24 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a dark purple solid.

[0065] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted with methanol solvent to 1 mg / mL to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 1 mL / h. Secondly, the FTO conductive glass is ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min each, and then blown clean with nitrogen gas to obtain a clean FTO conductive glass. Thirdly, the distance between the metal needle and the FTO conductive glass is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the FTO conductive glass. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the FTO conductive glass in a molecular state. Finally, the spraying area is set to 2.5 × 20 cm. 2 The spraying time was set to 1 hour, and after spraying, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of about 0.55 μm was obtained.

[0066] In this embodiment, UV-Vis absorption spectroscopy and X-ray diffraction analysis showed that the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in this embodiment were consistent with the results of Example 1. The results of SEM and AFM observations of the two-dimensional metal supramolecular polymer electrochromic nanomaterials in this embodiment were also similar to those in Example 1. The spectral changes and electrochromic response speed of the two-dimensional metal supramolecular polymer electrochromic nanofilm in this embodiment were tested using an electrochemical workstation and spectrophotometer. This indicates that the two-dimensional metal supramolecular polymer electrochromic nanofilm has the advantages of a large optical modulation range, fast response speed, and good cycling performance.

[0067] Example 7 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 5.3 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 °C for 20 h. After the solution cools to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3-dibromo-5-methylbenzene via a Suzuki coupling reaction to obtain bidentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1M Na2CO3 aqueous solution. Then, 125 mg of 1,3-dibromobenzene, 531 mg of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 30 mg of tetra(triphenylphosphine)palladium are added to a 100 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 5 mL of 1M Na2CO3 aqueous solution and 30 mL of tetrahydrofuran are added. The above solution is reacted at 75 °C for 48 h. The solution was cooled to room temperature, filtered, washed, and dried to obtain a white powder intermediate II (4',4''''-(5'-methyl-[1,1':3',1''-terphenyl]-4,4''-diyl)bis-2,2':6',2''-terpyridine). Step S3: The 4',4''''-(5'-methyl-[1,1':3',1''-terphenyl]-4,4''-diyl)di-2,2':6',2''-terpyridine obtained in step S2 was reacted with ferrous acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 141 mg of 4',4''''-(5'-methyl-[1,1':3',1''-terphenyl]-4,4''-diyl)di-2,2':6',2''-terpyridine and 35 mg of Fe(OAc)2 were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 24 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a dark purple solid.

[0068] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted with methanol solvent to 1 mg / mL to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 1 mL / h. Secondly, the FTO conductive glass is ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min each, and then blown clean with nitrogen gas to obtain a clean FTO conductive glass. Thirdly, the distance between the metal needle and the FTO conductive glass is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the FTO conductive glass. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the FTO conductive glass in a molecular state. Finally, the spraying area is set to 2.5 × 20 cm. 2 The spraying time was set to 1 hour, and after spraying, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of about 0.55 μm was obtained.

[0069] In this embodiment, UV-Vis absorption spectroscopy and X-ray diffraction analysis showed that the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in this embodiment were consistent with the results of Example 1. The results of SEM and AFM observations of the two-dimensional metal supramolecular polymer electrochromic nanomaterials in this embodiment were also similar to those in Example 1. The spectral changes and electrochromic response speed of the two-dimensional metal supramolecular polymer electrochromic nanofilm in this embodiment were tested using an electrochemical workstation and spectrophotometer. This indicates that the two-dimensional metal supramolecular polymer electrochromic nanofilm has the advantages of a large optical modulation range, fast response speed, and good cycling performance.

[0070] Example 8 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 4.8 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 70 °C for 12 h. After the solution cools to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). White powder intermediate I 1 H NMR (300 MHz, CD3OD, 300 K, δ, ppm): 8.68 (d, J = 4.7Hz, 2H), 8.64 (s, 2H), 8.61 (d, J = 8.0 Hz, 2H), 7.98 (t, J = 7.8 Hz, 2H), 7.76 (s, 4H), 7.53 - 7.40 (m, 2H); 13 C NMR (75 MHz, CDCl3, 300 K, δ, ppm): δ157.6, 157.0, 150.0, 138.8, 135.2, 125.3, 123.0, 119.6; ESI-MS (m / z): Calcd. for [C 21 H 16 BN3O2+H] + Found: 354.13; S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3-dibromo-5-methylbenzene via a Suzuki coupling reaction to obtain bidentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1 M Na2CO3 aqueous solution. Then, 410 mg of 1,3-dibromo-5-methylbenzene, 1.74 g of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 74 mg of tetra(triphenylphosphine)palladium are added to a 500 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 5 mL of 1 M Na2CO3 aqueous solution and 210 mL of tetrahydrofuran are added. The above solution is reacted at 70 °C for 72 h. The solution was cooled to room temperature, filtered, washed, and dried to obtain a white powder intermediate II (4',4''''-(5'-methyl-[1,1':3',1''-terphenyl]-4,4''-diyl)bis-2,2':6',2''-terpyridine). White powder intermediate II 1 H NMR (500 MHz, CDCl3, 500 K, δ, ppm): 8.82 (s, 4H), 8.76 (ddd, J = 4.8, 1.8, 0.9 Hz, 4H), 8.70 (dt, J = 7.9, 1.0 Hz, 4H), 8.07 – 8.01 (m, 4H), 7.90 (td, J= 7.7, 1.8 Hz, 4H), 7.86 – 7.80 (m, 4H), 7.76 (d, J = 1.8 Hz, 1H), 7.51 (dd, J = 1.8, 0.9 Hz, 2H), 7.37 (ddd, J = 7.5, 4.8, 1.2 Hz, 4H); 13 C NMR (125MHz, CDCl3, 300 K, δ, ppm): 156.2,155.9,149.8,149.1,141.8,141.1,139.0,137.4,136.8,127.7,127.3,123.8,123.3,121.4,118.7; ESI-TOF (m / z): Calcd. for [C 49 H 34 N6+H] + Found: 707.28; S3. The 4',4''''-(5'-methyl-[1,1':3',1''-terphenyl]-4,4''-diyl)di-2,2':6',2''-terpyridine obtained in step S2 was reacted with cobalt acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 141 mg of 4',4''''-(5'-methyl-[1,1':3',1''-terphenyl]-4,4''-diyl)di-2,2':6',2''-terpyridine and 53 mg of Co(OAc)2 were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of glacial acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 6 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a dark purple solid.

[0071] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted with methanol solvent to 1 mg / mL to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 0.8 mL / h. Secondly, the ITO / PET substrate is ultrasonically cleaned for 15 min each with acetone, deionized water, and ethanol, and then purged with nitrogen gas to obtain a clean ITO / PET substrate. Thirdly, the distance between the metal needle and the ITO / PET substrate is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the ITO / PET substrate. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the ITO / PET substrate in a molecular state. Finally, the spraying area is set to 25 × 30 cm. 2 The spraying time was set to 24 hours. After the spraying was completed, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of about 0.4 μm was obtained.

[0072] In this embodiment, UV-Vis absorption spectroscopy and X-ray diffraction analysis showed that the two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared in this embodiment were consistent with the results of Example 1. The results of SEM and AFM observations of the two-dimensional metal supramolecular polymer electrochromic nanomaterials in this embodiment were also similar to those in Example 1. The spectral changes and electrochromic response speed of the two-dimensional metal supramolecular polymer electrochromic nanofilm in this embodiment were tested using an electrochemical workstation and spectrophotometer. This indicates that the two-dimensional metal supramolecular polymer electrochromic nanofilm has the advantages of a large optical modulation range, fast response speed, and good cycling performance.

[0073] Example 9 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 10.5 g of 2-acetylpyridine and 2.6 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 °C for 24 h. After the solution cools to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3,5-tribromobenzene via a Suzuki coupling reaction to obtain tridentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1 M Na2CO3 aqueous solution. Then, 393 mg of 1,3,5-tribromobenzene, 1.74 g of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 83 mg of tetra(triphenylphosphine)palladium are added to a 500 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 30 mL of 1 M Na2CO3 aqueous solution and 210 mL of tetrahydrofuran are added. The above solution is reacted at 80 °C for 24 h. The solution was cooled to room temperature, filtered, washed, and dried to give a white powder intermediate II (1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene). S3. The 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene obtained in step S2 was reacted with ruthenium trichloride trihydrate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 100 mg of 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene and 52.2 mg of RuCl3•3H2O were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, under nitrogen protection, 30 mL of a mixed solution of chloroform and methanol (volume ratio 1:2) was slowly added, and the mixture was stirred and refluxed for 12 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain a light red solid.

[0074] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted with methanol solvent to 0.1 mg / mL to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 0.8 mL / h. Secondly, the FTO conductive glass is ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min each, and then blown clean with nitrogen gas to obtain a clean FTO conductive glass. Thirdly, the distance between the metal needle and the FTO conductive glass is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the FTO conductive glass. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the FTO conductive glass in a molecular state. Finally, the spraying area is set to 2.5 × 5 cm. 2 The spraying time was set to 1.5 hours. After the spraying was completed, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of 362 nm was obtained.

[0075] Example 10 This embodiment describes the preparation method and application of two-dimensional metal supramolecular polymer electrochromic nanomaterials. The steps are as follows: (1) Preparation methods of two-dimensional metal supramolecular polymer electrochromic nanomaterials, such as Figure 1 As shown, it includes the following steps: The preparation method of S1, 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid is as follows: Specifically, firstly, 4.8 g of NaOH powder is dissolved in 100 mL of anhydrous ethanol; then, 5.3 g of 2-acetylpyridine and 3.0 g of 4-formylphenylboronic acid are added to a 250 mL round-bottom flask, and the above solution is stirred at room temperature for 24 h; finally, 75 mL of ammonia water (28%) is slowly added, and the mixture is refluxed at 80 °C for 24 h. After the solution cools to room temperature, it is filtered and dried to obtain a white powder intermediate I (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid). S2. The 4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid obtained in step S1 is reacted with 1,3,5-tribromobenzene via a Suzuki coupling reaction to obtain tridentate terpyridine. Specifically, first, 1.06 g of Na2CO3 is added to 10 mL of deionized water to prepare a 1 M Na2CO3 aqueous solution. Then, 393 mg of 1,3,5-tribromobenzene, 1.74 g of (4-([2,2':6',2''-terpyridine]-4'-yl)phenyl)boronic acid and 83 mg of tetra(triphenylphosphine)palladium are added to a 500 mL Schlenk flask. The mixture is evacuated and purged with nitrogen three times. Under a nitrogen flow, 30 mL of 1 M Na2CO3 aqueous solution and 210 mL of tetrahydrofuran are added. The above solution is reacted at 80 °C for 24 h. The solution was cooled to room temperature, filtered, washed, and dried to give a white powder intermediate II (1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene). S3. The 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene obtained in step S2 was reacted with cobalt acetate to obtain a two-dimensional metal supramolecular polymer electrochromic nanomaterial. Specifically, 100 mg of 1,3,5-tris(4-(2,2':6',2''-terpyridine)phenyl)benzene and 35.4 mg of cobalt acetate were added to a 100 mL round-bottom flask, and the mixture was evacuated and purged with nitrogen three times. Then, 30 mL of glacial acetic acid was slowly added under nitrogen protection, and the mixture was stirred and refluxed for 12 h. After cooling to room temperature, the mixture was filtered, washed, and dried to obtain an orange solid.

[0076] (2) This embodiment also provides the application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial prepared using the preparation method of this embodiment. In this embodiment, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is used to prepare a two-dimensional metal supramolecular polymer electrochromic nanofilm. The preparation of the two-dimensional metal supramolecular polymer electrochromic nanofilm includes the following steps: Y1. The prepared two-dimensional metal supramolecular polymer electrochromic nanomaterials are dispersed in a solvent to obtain nanomaterial ink. Specifically, the two-dimensional metal supramolecular polymer electrochromic nanomaterials obtained in step S3 are diluted with methanol solvent to 0.3 mg / mL to prepare an electrostatic spraying precursor liquid, i.e., nanomaterial ink; Y2. The nanomaterial ink obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate using a wet film deposition method. Specifically, firstly, the electrostatic spraying precursor liquid prepared in step Y1 is injected into a syringe with a metal needle, which is then installed in a micro-injection pump with a propulsion rate of 0.8 mL / h. Secondly, the FTO conductive glass is ultrasonically cleaned with acetone, deionized water, and ethanol for 15 min each, and then blown clean with nitrogen gas to obtain a clean FTO conductive glass. Thirdly, the distance between the metal needle and the FTO conductive glass is fixed at 10 cm, and a high voltage of 20 kV is applied between the metal needle and the FTO conductive glass. The electrostatic spraying precursor liquid is atomized into an aerogel, and under the action of electrostatic attraction, the two-dimensional metal supramolecular polymer is deposited on the surface of the FTO conductive glass in a molecular state. Finally, the spraying area is set to 2.5 × 5 cm. 2 The spraying time was set to 3 hours. After the spraying was completed, a uniform porous two-dimensional metal supramolecular polymer electrochromic nanofilm with a thickness of 704 nm was obtained.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing two-dimensional metal supramolecular polymer electrochromic nanomaterials, characterized in that, The steps are as follows: S1. 2-Acetylpyridine and 4-formylphenylboronic acid were refluxed in the presence of ammonia. After the reaction was completed, post-treatment was performed. Intermediate I is obtained; in step S1, the molar ratio of 4-formylphenylboronic acid to 2-acetylpyridine is 1:(2~5); S2. Intermediate I obtained in step S1 and the polysubstituted benzene are subjected to a Suzuki coupling reaction in tetrahydrofuran under nitrogen atmosphere. After the reaction is completed, after post-treatment, intermediate II is obtained. The polysubstituted benzene in step S2 is any one of 1,3,5-bromobenzene, 1,3,5-iodobenzene, 1,3-dibromo-5-methylbenzene, or 1,3-dibromobenzene. The molar ratio of the polysubstituted benzene to intermediate I is 1:(3~5). S3. The intermediate II obtained in step S2 is refluxed with metal ions in an organic solvent under nitrogen atmosphere. After the reaction is completed, the two-dimensional metal supramolecular polymer electrochromic nanomaterial is obtained through post-treatment. The molar ratio of intermediate II to metal ions is 1:(1~3).

2. The method for preparing two-dimensional metal supramolecular polymer electrochromic nanomaterials according to claim 1, characterized in that: In step S1, the mass fraction of ammonia is 28%, the reflux reaction temperature is 70~80℃, and the reflux reaction time is 12~24h.

3. The method for preparing two-dimensional metal supramolecular polymer electrochromic nanomaterials according to claim 2, characterized in that: In step S2, the catalyst for the Suzuki coupling reaction is tetra(triphenylphosphine)palladium, the molar ratio of tetra(triphenylphosphine)palladium to polysubstituted benzene is (0.04~0.1):1, the temperature of the Suzuki coupling reaction is 70~80℃, and the time of the Suzuki coupling reaction is 24~72 h.

4. The method for preparing two-dimensional metal supramolecular polymer electrochromic nanomaterials according to claim 3, characterized in that: In step S3, the metal ion is any one of iron ion, cobalt ion or ruthenium ion; the organic solvent is glacial acetic acid or a mixed solution of chloroform and methanol, the volume ratio of chloroform to methanol is 1:(2~3), the reflux reaction temperature is 60~130℃, and the reflux reaction time is 6~24h.

5. Two-dimensional metal supramolecular polymer electrochromic nanomaterials prepared by any one of claims 1-4.

6. The application of the two-dimensional metal supramolecular polymer electrochromic nanomaterial according to claim 5 in two-dimensional metal supramolecular polymer electrochromic nanofilms.

7. The application according to claim 6, characterized in that, The steps are as follows: Y1. Dissolve the two-dimensional metal supramolecular polymer electrochromic nanomaterial in a solvent to obtain an ink of the two-dimensional metal supramolecular polymer electrochromic nanomaterial. Y2. The ink of the two-dimensional metal supramolecular polymer electrochromic nanomaterial obtained in step Y1 is used to construct a two-dimensional metal supramolecular polymer electrochromic nanofilm on a cleaned transparent conductive substrate by a wet film forming method.

8. The application according to claim 7, characterized in that: The solvent in step Y1 is DMF or a low-boiling-point alcohol solvent, wherein the low-boiling-point alcohol solvent is methanol or ethanol, and the concentration of the two-dimensional metal supramolecular polymer electrochromic nanomaterial in the ink is 0.1~1 mg / mL; the wet film formation method in step Y2 is any one of spin coating, spray coating or inkjet printing, and the cleaning treatment is to ultrasonically clean the conductive substrate with acetone, deionized water and ethanol respectively and blow it clean with compressed air.

9. The application according to any one of claims 6-8, characterized in that: The thickness of the two-dimensional metal supramolecular polymer electrochromic nanofilm is 0.2 μm to 1 μm.

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