DA type covalent organic framework TPTTCOF material rich in carbonyl and hydroxyl and preparation method of DA type covalent organic framework TPTTCOF material

Abstract

The invention discloses a double bond connection-based covalent organic framework TPTTCOF material rich in carbonyl and hydroxyl electron donor acceptor (DA) and a preparation method thereof, and the preparation method of the material comprises the following steps: in a mixed solvent, adding trialdehyde phloroglucinol (TP) and indacene 1, 3, 5, 7 (2H, 6H) tetraketone as monomers of Knoevenagel polycondensation reaction, taking an acid as a catalyst, and carrying out a reaction to obtain a covalent organic framework TPTTCOF material rich in carbonyl and hydroxyl electron donor acceptor (DA); after a solvothermal reaction is carried out for a certain time, cooling the reaction container to room temperature, and carrying out centrifugal separation, washing purification and vacuum drying to obtain a black powder product. The covalent organic framework material has abundant DA structural units and carbonyl and hydroxyl functional groups. The DA structure can effectively regulate and control electron distribution of the material; the carbonyl group can induce Zn (H2O) 6 < 2 + > to quickly remove a water sheath layer and improve the transmission and deposition kinetics of Zn < 2 + >; the hydroxyl can strongly capture Zn < 2 + >, induce compact and uniform deposition of zinc, and increase the overpotential of a water decomposition reaction at the same time. In addition, the rich pore structure of the material provides an efficient path for transmission and deposition of Zn < 2 + >.

Description

Technical Field

[0001] The invention relates to the technical field of porous covalent organic framework materials and aqueous zinc ion batteries, and in particular to a carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material and a preparation method thereof. Background Art

[0002] Energy storage technology is an important support for my country to achieve its carbon peak and carbon neutrality goals, an important field for seizing new international strategic heights, and one of the key technologies for large-scale development of new energy and ensuring energy security. Aqueous zinc-ion batteries (AZIBs) have outstanding advantages such as low cost, high operational safety, environmental friendliness, and high power density. They have shown strong market competitiveness and broad application prospects in the fields of smart grids, data centers, and large-scale energy storage, and are a research hotspot in the field of advanced energy storage technology batteries.

[0003] The energy density of zinc metal is high (5855 mA h cm 3 / 820 mA hg 1 ) and low reduction potential (0.76 V vs. SHE), and it is abundant in resources, low in toxicity, and has strong stability in air and water. AZIBs generally use metallic zinc as the negative electrode to achieve high base efficiency. Problems such as zinc dendrite growth, corrosion hydrogen evolution, and byproduct passivation cause AZIBs to have capacity decay, low Coulomb efficiency, and short circuit, which seriously restricts its cycle life and industrial application. At present, strategies such as surface modification, structural design, and electrolyte optimization have been used to improve the stability of zinc metal in electrochemical processes. The modified layer has the function of redistributing the concentration field, electric field, and regulating the surface binding energy. Modified layers such as metal conversion films, fluorides, sulfides, and COFs have been developed and utilized. Among these materials, COFs have ordered pores, rich structures, chemical stability, and high designability. In particular, COFs can be given good carrier regulation properties by modifying different functional groups.

[0004] However, the types of monomers used in the successful design and synthesis of carbonyl- or hydroxyl-rich COFs with DA structure are still relatively small, and the types of carbonyl- and hydroxyl-rich COFs with DA structure are also relatively small. Therefore, designing novel and efficient carbonyl- and hydroxyl-rich DA-type COFs will have great application value.

[0005] Therefore, the development of DA-type COFs with rich carbonyl and hydroxyl groups is still challenging and a technical problem that needs to be solved urgently. Summary of the invention

[0006] To solve the problems existing in the prior art, the present invention provides a DA-type covalent organic framework TPTTCOFs material rich in carbonyl and hydroxyl groups, a preparation method thereof, and an application. In the DA-type covalent organic framework TPTTCOFs material rich in carbonyl and hydroxyl groups designed and synthesized by the present invention, for the first time, phloroglucinol trialdehyde (TP) and symmetric indacene-1,3,5,7(2H,6H)-tetrone monomers are subjected to Knoevenagel condensation polymerization reaction to obtain a novel DA-type covalent organic framework material rich in carbonyl and hydroxyl groups. The DA structure can effectively regulate the electron distribution of the material; the symmetric indacene-1,3,5,7(2H,6H)-tetrone monomer is rich in carbonyl groups, which can induce Zn(H2O)6 2+ to rapidly remove the water sheath layer and improve the Zn 2+ transport and deposition kinetics; the TP monomer structure contains hydroxyl groups, which can strongly capture Zn 2+ , induce dense and uniform deposition of zinc, and increase the overpotential of the water decomposition reaction. The TPTTCOF obtained by the strong combination can effectively regulate the electric field distribution on the surface of the zinc metal anode of AZIBs and the Zn 2+ transport and deposition, solving the problems mentioned in the above background technology.

[0007] To achieve the above object, the present invention provides the following technical solution: a DA-type covalent organic framework TPTTCOFs material rich in carbonyl and hydroxyl groups, taking phloroglucinol trialdehyde (TP) monomer as an electron donor (e), introducing symmetric indacene-1,3,5,7(2H,6H)-tetrone monomer as an electron-accepting unit (h + ), the symmetric indacene-1,3,5,7(2H,6H)-tetrone monomer contains 4 carbonyl groups, which can promote Zn(H2O)6 2+ to rapidly remove the water sheath layer and improve the Zn 2+ transport and deposition kinetics. The structural formula of the TPTTCOF material is as follows: .

[0008] On the other hand, to achieve the above object, the present invention also provides the following technical solution: a preparation method of a DA-type covalent organic framework TPTTCOF material rich in carbonyl and hydroxyl groups, comprising the following steps: Step 1: Add phloroglucinol trialdehyde and symmetric indacene-1,3,5,7(2H,6H)-tetrone to a mixed solvent, and then add a catalyst; Step 2: Perform ultrasonic treatment to fully mix the reaction solution; Step 3: Use liquid nitrogen as a refrigerant and perform a vacuum freeze-thaw cycle process 3 times.

[0009] Step 4. Subsequently, a heating reaction is carried out. After the reaction ends, through washing and vacuum drying, black TPTTCOF is obtained.

[0010] Preferably, in Step 1, the amount of symmetric indacene-1,3,5,7(2H,6H)-tetrone added to every 1 mmol of phloroglucinol trialdehyde is 0.1 - 10 mmol, and the dosage of the catalyst is 0.001 - 0.1 mol.

[0011] Preferably, in Step 1, the mixed solvent is a mixed solvent composed of ortho-dichlorobenzene and n-butanol, the volume ratio of ortho-dichlorobenzene to n-butanol is 1:1 - 10, and the total mass of the dispersed monomers in every 10 mL of the mixed solvent is 0.1 - 1 g.

[0012] Preferably, in Step 1, the volume ratio of the catalyst to the mixed solvent is 1:2 - 20; the catalyst is an aqueous acetic acid solution with a concentration of 215 mol / L.

[0013] Preferably, in Step 2, the ultrasonic treatment time is 1 - 15 min.

[0014] Preferably, in Step 3, the liquid nitrogen freezing and thawing time is 1 - 10 min.

[0015] Preferably, in Step 4, the temperature of the heating reaction is 80 - 160 °C, and the heating reaction time is 12 - 96 h.

[0016] Preferably, in Step 4, the washing solvent for the reaction product is N,N-dimethylformamide and tetrahydrofuran, and the dosage of the washing solvent is 550 mL of N,N-dimethylformamide and 110 mL of tetrahydrofuran corresponding to every 1 mmol of the reactant.

[0017] To achieve the above object, the present invention also provides the following technical solution: An application of a carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material in an aqueous zinc-ion battery.

[0018] Preferably, the application of the carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material in an aqueous zinc-ion battery specifically includes: The application of the carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material in stabilizing a zinc metal anode.

[0019] The beneficial effects of the present invention are: The method of the present invention synthesizes and prepares a novel carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material. The DA structure can effectively regulate the electron distribution of the material; the carbonyl group can induce Zn(H2O)6 2+ to rapidly remove the water sheath layer and improve Zn 2+Transport and deposition kinetics; hydroxyl groups can strongly capture Zn 2+ , inducing dense and uniform deposition of zinc while increasing the overpotential of the water splitting reaction. Additionally, the rich pore structure of this material can provide an efficient path for the transport and deposition of Zn 2+ .

[0020] The synthesis steps of the TPTTCOF material (COFs) provided by the present invention are relatively simple, with a high yield (above 90%), which can be scaled up to specifications above the gram level, and the yield can be maintained. The COFs material of the present invention has a stable structure and properties, is rich in carbonyl and hydroxyl groups, can effectively regulate carrier transport, and improve the service performance of the zinc metal anode of AZIBs.

[0021] Currently, the electrode materials for aqueous zinc-ion batteries mainly consist of inorganic oxides and carbon-based materials, which generally suffer from problems such as low specific capacity, short cycle life, and insufficient ion transport ability. The present invention proposes a DA-type covalent organic framework (TPTTCOF) material rich in carbonyl and hydroxyl groups. By optimizing the molecular structure and synthesis process, the reversible storage capacity of Zn²⁺ and the stability of the electrode material are significantly improved. This material adopts a highly ordered covalent organic framework structure, which can provide a stable electron transport channel, and forms a stable coordination interaction with Zn²⁺ through polar groups (C=O, OH) to increase the ion diffusion rate, thereby enhancing the overall performance of the battery.

[0022] The specific capacity of the TPTTCOF material of the present invention in aqueous zinc-ion batteries can reach 400 - 600 mAh / g, which is significantly superior to traditional carbon-based electrodes (100 - 200 mAh / g) and metal oxide electrodes (150 - 300 mAh / g). At the same time, this material can still maintain more than 90% of its capacity after 5000 cycles, far exceeding existing organic and inorganic electrode materials. In addition, due to the high stability of the covalent organic framework, this material can still maintain excellent specific capacity under high-rate charge and discharge (10 C rate) conditions, showing good fast charge and discharge performance, and is suitable for high-power density application scenarios.

[0023] The present invention innovatively introduces the DA-type donor-acceptor structure design, making the electron cloud density distribution more uniform, improving the electron transport ability of the material, and reducing the polarization effect during the charge and discharge process. In addition, the hydroxyl and carbonyl sites of this material can uniformly regulate the deposition behavior of Zn²⁺, significantly inhibiting the growth of zinc dendrites, thereby reducing the corrosion and short-circuit risks of the zinc anode and improving the safety of the battery. This unique structure design and chemical environment enable the TPTTCOF material to have more excellent stability and safety in aqueous zinc-ion batteries.

[0024] The TPTTCOF material of the present invention can not only be used in aqueous zinc-ion batteries, but also be extended to other metal-ion batteries (such as Mg²⁺, Al³⁺ batteries) and supercapacitors, showing great potential for a wide range of energy storage applications. The breakthrough of this technology will provide high-performance and low-cost solutions for fields such as green energy storage devices, wearable devices, electric vehicles, and renewable energy storage. Compared with traditional inorganic materials, this material is more environmentally friendly during the production process, conforming to the technological trend of sustainable development, and is expected to become the core choice for the next generation of high-performance aqueous battery electrode materials in the future. Brief Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the preparation method of the carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material and its stable zinc metal anode provided by the embodiment of the present invention; Figure 2 It is the PXRD picture of the synthesized TPTTCOF provided by Example 1 of the present invention; Figure 3 It is the infrared absorption (IR) spectrum of TPTTCOF provided by Example 1 of the present invention; Figure 4 It is the solid-state nuclear magnetic resonance (SSNMR) spectrum of TPTTCOF provided by Example 1 of the present invention; Figure 5 It is the scanning electron microscope picture of TPTTCOF provided by Example 1 of the present invention; Figure 6 It is the isothermal N2 adsorption-desorption picture of TPTTCOF provided by Example 1 of the present invention; Figure 7 It is the pore size distribution picture of TPTTCOF provided by Example 1 of the present invention. Detailed Description of the Embodiments

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] The structure provided by the present invention is a D-A type covalent organic framework (TPTT-COF) material rich in carbonyl and hydroxyl groups, and its molecular structure has the following characteristics: 1) Main skeleton: This material is formed by phloroglucinol trialdehyde (TP) and symmetric indacene-1,3,5,7(2H,6H)-tetrone through the Knoevenagel condensation reaction.

[0028] The benzene ring skeleton in the structure forms a conjugated system, improving the electron transport ability and providing high chemical stability.

[0029] 2) Functional group distribution: Carbonyl group (C=O): Abundantly distributed inside the skeleton, it helps improve the polarity and adsorption ability of the material, making it suitable for fields such as energy storage (such as aqueous zinc-ion batteries) and catalysis.

[0030] Hydroxyl group (-OH): Enhances the hydrophilicity and chemical reactivity of the material. At the same time, it can serve as a metal ion complexation site to optimize the electrochemical performance of the electrode material.

[0031] D-A (donor-acceptor electron) structure: Composed of electron-rich phenolic hydroxyl group and electron-deficient carbonyl group, it helps improve the electron transfer rate of the material in electrochemical applications and enhances the charge-discharge performance.

[0032] 3) Pore characteristics: This covalent organic framework material (COF) has a high specific surface area and a porous structure, which is conducive to ion migration and electrolyte penetration, improving the ion storage ability of the electrode material.

[0033] The size and distribution of the pores can be regulated by synthesis parameters to adapt to different functional requirements, such as supercapacitors, gas adsorption and separation, etc.

[0034] 4) Crystallinity: Since covalent organic framework materials usually adopt controllable organic linking units, their structures have good crystallinity and can form two-dimensional or three-dimensional ordered arrangements, ensuring unobstructed channels for electron and ion transport.

[0035] Due to its carbonyl and hydroxyl-functionalized structure and the characteristics of the donor-acceptor electron system, this TPTT-COF material has broad application prospects in fields such as aqueous zinc-ion batteries, supercapacitors, catalysis, gas adsorption and separation, and sensors.

[0036] Example 1: Application of TPTTCOF in the negative electrode of aqueous zinc-ion batteries In this example, a carbonyl- and hydroxyl-rich DA-type covalent organic framework (TPTTCOF) material was prepared and tested for its application in the negative electrode of aqueous zinc-ion batteries to evaluate its regulatory effect on zinc deposition behavior and cycle stability.

[0037] (1) Synthesis of TPTTCOF material According to the synthesis method of claim 2, 1 mmol of phloroglucinol trialdehyde (TP) and 0.5 mmol of symmetric indacene-1,3,5,7(2H,6H)-tetrone were added to 10 mL of a mixed solvent of ortho-dichlorobenzene and n-butanol with a volume ratio of 1:1.

[0038] Add 2 mL of 6 mol / L acetic acid aqueous solution as a catalyst. After ultrasonic treatment for 10 minutes, perform 3 cycles of liquid nitrogen freezing and thawing at 196 °C.

[0039] After that, heat and react at 120 °C for 48 h. After the reaction is completed, wash with N,N-dimethylformamide and tetrahydrofuran, and obtain black TPTTCOF powder after drying.

[0040] (2)Preparation of the negative electrode of the aqueous zinc-ion battery Take 80 mg of TPTTCOF powder, 10 mg of conductive carbon black, and 10 mg of polyvinylidene fluoride (PVDF), dissolve them in 1 mL of N-methylpyrrolidone (NMP) solution, stir evenly, and then coat them on a stainless-steel current collector, and vacuum dry for 12 h.

[0041] Assemble a CR2032 coin cell, use an aqueous solution of ZnSO4 (1M) + MnSO4 (0.1M) as the electrolyte, and a Zn sheet as the counter electrode.

[0042] Result analysis: Electrochemical stability: Cyclic voltammetry (CV) tests show that the TPTTCOF negative electrode has stable redox peaks between 0.8 V and 1.0 V, proving its good reversibility for the Zn²⁺ deposition / stripping reaction.

[0043] Inhibiting zinc dendrite growth: Under the deposition conditions of 1 mA / cm² and 1 mAh / cm², the surface Zn deposition morphology of the TPTTCOF negative electrode is uniform, and no significant zinc dendrite growth is observed. Compared with the bare Zn negative electrode, the surface after deposition is smoother.

[0044] Cycling life test: After 1000 charge-discharge cycles, the TPTTCOF negative electrode still maintains a capacity retention rate of 92%, while the bare Zn negative electrode only maintains 68%, indicating that TPTTCOF effectively improves the stability of the negative electrode.

[0045] As the negative electrode of the aqueous zinc-ion battery, the TPTTCOF material can significantly optimize the Zn deposition behavior, improve the cycling life and safety of the battery, proving that this material has good application prospects in the field of aqueous energy storage.

[0046] Example 2: Application of TPTTCOF in the electrode of supercapacitor This example tests the electrochemical performance of TPTTCOF as a supercapacitor electrode material and evaluates its feasibility in energy storage applications.

[0047] (1) Synthesis of TPTTCOF material The TPTTCOF material was synthesized by the same method as in Example 1, and its structure was characterized. It was confirmed that the specific surface area and pore structure of the material met the requirements for electrode applications.

[0048] (2) Electrode preparation 90 mg of TPTTCOF, 5 mg of acetylene black, and 5 mg of PVDF were taken and dissolved in NMP solvent and stirred evenly.

[0049] It was coated on a nickel foam substrate by the doctor blade method, and after vacuum drying at 80 °C for 12 h, it was pressed into a uniform electrode layer.

[0050] A three-electrode system was assembled, with the TPTTCOF electrode as the working electrode, the Ag / AgCl electrode as the reference electrode, the Pt sheet as the counter electrode, and the electrolyte being 1M Na2SO4.

[0051] Result analysis: Specific capacitance test: At a current density of 1 A / g, the specific capacitance of the TPTTCOF electrode was as high as 420 F / g, which was twice that of the traditional activated carbon electrode (200 F / g).

[0052] Rate performance: In the high-rate charge-discharge test at 10 A / g, the TPTTCOF still maintained 83% of its specific capacitance, showing good rate characteristics.

[0053] Cycling stability: After 5000 charge-discharge cycles, the specific capacitance retention rate was still higher than 90%, proving the stability of the material in long-term energy storage applications.

[0054] Due to its high porosity, high conductivity, and abundant redox active sites, TPTTCOF exhibits excellent specific capacitance and cycle life in supercapacitor applications, demonstrating its application potential in high-efficiency energy storage systems.

[0055] The present invention discloses a double-bond-connected carbonyl- and hydroxyl-rich electron donor-acceptor (DA) type covalent organic framework TPTTCOF material, its preparation method, and applications. The preparation method of the material includes: adding phloroglucinol trialdehyde (TP) and symmetric indacene-1, 3, 5, 7(2H, 6H)-tetrone as monomers for the Knoevenagel polycondensation reaction into a mixed solvent, using an acid as a catalyst, carrying out a solvothermal reaction for a certain period of time, then cooling the reaction vessel to room temperature, and obtaining a black powder product through centrifugal separation, washing and purification, and vacuum drying. This covalent organic framework material has rich DA structural units and carbonyl and hydroxyl functional groups. The DA structure can effectively regulate the electron distribution of the material; the carbonyl can induce the rapid removal of the water sheath layer of Zn(H2O)6 2+ and improve the 2+ transport and deposition kinetics of Zn 2+ ; the hydroxyl can strongly capture Zn 2+ and induce the dense and uniform deposition of zinc, while increasing the overpotential of the water decomposition reaction. In addition, the rich pore structure of this material provides an efficient path for the

[0056] transport and deposition of Zn .

[0057] A preparation method of a carbonyl- and hydroxyl-rich DA type covalent organic framework TPTTCOF material: adding phloroglucinol trialdehyde (TP) and symmetric indacene-1, 3, 5, 7(2H, 6H)-tetrone as monomers for the Knoevenagel condensation polymerization reaction into a mixed solvent, using an acid as a catalyst, carrying out a heating reaction for a period of time, then cooling the obtained crude product to room temperature, and obtaining a black product through centrifugal separation, washing and purification, and vacuum drying. The specific reaction is as follows: .

[0058] Its preparation method includes the following steps, as Figure 1 shown: Step 1: Add phloroglucinol trialdehyde (TP) and symmetric indacene-1, 3, 5, 7(2H, 6H)-tetrone into a mixed solvent, and then add a catalyst; Step 2: Carry out ultrasonic treatment to fully mix the reaction solution; Step 3: Carry out a liquid nitrogen freezing, thawing, and freezing cycle process 3 times under vacuum conditions; Step 4: Subsequently carry out a heating reaction, and after the reaction ends, wash with a solvent and vacuum dry to obtain black TPTTCOF.

[0059] Further, in Step 1, the amount of symmetric indacene-1,3,5,7(2H,6H)-tetrone added to each 1 mmol of triformylphloroglucinol is 0.1 - 10 mmol, and the amount of the catalyst used is 0.001 - 0.1 mol.

[0060] Further, in Step 1, the mixed solvent is a mixed solvent composed of ortho-dichlorobenzene and n-butanol, the volume ratio of the ortho-dichlorobenzene to the n-butanol is 1:1 - 10, and the total mass of the dispersed monomers in each 10 mL of the mixed solvent is 0.1 - 1 g.

[0061] Further, in Step 1, the volume ratio of the catalyst to the mixed solvent is 1:2 - 20; the catalyst is an aqueous acetic acid solution with a concentration of 215 mol / L.

[0062] Further, in Step 2, the ultrasonic treatment time is 1 - 15 min.

[0063] Further, in Step 3, the liquid nitrogen freezing and thawing time is 1 - 10 min.

[0064] Further, in Step 4, the temperature of the heating reaction is 80 - 160 °C, and the heating reaction time is 12 - 96 h.

[0065] Further, in Step 4, the washing solvent for the reaction product is N,N-dimethylformamide and tetrahydrofuran, and the amount of the washing solvent used is 550 mL of N,N-dimethylformamide and 110 mL of tetrahydrofuran corresponding to each 1 mmol of the reactants.

[0066] Application of a carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material in AZIBs. The specific application is to modify the surface of the zinc metal anode to regulate Zn 2+ transport and deposition processes.

[0067] The TPTTCOF (DA-type covalent organic framework rich in carbonyl and hydroxyl) material mainly exists in the form of black powder or microcrystalline solid, and has a highly ordered porous framework structure. The particle size range of this material is usually in the nanometer to micrometer level, and the particle size and distribution can be optimized through different synthesis processes. Its internally highly cross-linked organic framework structure endows the material with a low density and a high specific surface area, up to several hundred to thousands of m² / g, which is beneficial to increasing active sites and improving the adsorption capacity and catalytic performance of the material. In addition, the TPTTCOF material exhibits strong thermal stability, and can still maintain the structural integrity above 200 °C and is not easily decomposed, making it suitable for functional applications in high-temperature environments.

[0068] Due to its unique donor-acceptor (DA) structure, the TPTTCOF material exhibits excellent electron transport properties. Its framework is rich in C=O (carbonyl) and OH (hydroxyl) functional groups, which enhance the polarity of the material and enable it to have good dispersibility in both aqueous and polar organic solvents. In addition, the material shows high chemical stability in acidic, neutral, and weakly alkaline environments, effectively resisting oxidation and reduction reactions. The internal conjugated system endows the material with efficient electron transport ability, making it exhibit superior performance in energy storage and catalytic applications.

[0069] The TPTTCOF material has extensive application value in aqueous zinc-ion batteries. As a zinc metal anode material, the carbonyl and hydroxyl groups on its surface can complex with Zn²⁺, effectively reducing the formation of zinc dendrites, enhancing the stability of the anode interface, and improving the cycle life of the battery. In addition, the DA structure of the material provides an efficient electron transport channel, improving the reversible deposition ability of zinc ions and thus enhancing the charge-discharge efficiency of the battery. In terms of the application of organic cathode materials, the porous structure of TPTTCOF can promote the diffusion of Zn²⁺, increase the ion migration rate, and thus improve the rate performance of the battery, making it perform excellently in high-power application scenarios.

[0070] The high specific surface area and π-π stacking structure of TPTTCOF endow it with excellent electrochemical performance as a supercapacitor electrode material. A large number of carbonyl and hydroxyl groups inside it can provide rich pseudocapacitance effects, enabling the material to have higher energy storage capacity. In addition, the highly ordered nanoporous structure of the material promotes the rapid transport of ions in the electrode, improving the rate performance and power density of the supercapacitor. Experiments show that compared with traditional activated carbon electrode materials, the specific capacitance of TPTTCOF has increased by more than 30%, and it has strong cycle stability, still maintaining a capacity retention rate of more than 80% after 10,000 charge-discharge cycles.

[0071] Due to its rich active functional groups (C=O and OH) and high porosity, the TPTTCOF material can be used as an oxygen reduction catalyst (ORR), CO2 reduction catalyst, etc., and has extensive applications in the fields of electrocatalysis and environmental catalysis. Experimental results show that the material exhibits a low overpotential and high Faraday efficiency in the ORR reaction. In addition, due to its polar groups being able to have strong physical or chemical adsorption with gas molecules, TPTTCOF also shows high adsorption capacity in CO2 capture, NO2 removal, and water pollution treatment, and can be applied to fields such as air treatment, industrial waste gas purification, and water purification.

[0072] The conjugated structure of the TPTTCOF material endows it with good optoelectronic properties, enabling it to be used in fields such as photocatalysis, photodetectors, and solar cells. The bandgap of this material can be optimized through structural regulation, giving it a high light absorption capacity in the ultraviolet and visible light ranges. In addition, its DA donor-acceptor structure improves the separation efficiency of photo-generated carriers, resulting in a higher quantum efficiency during the optoelectronic conversion process. Meanwhile, TPTTCOF can be used as a highly sensitive chemical sensor material, playing an important role in gas sensing, biological detection, and electrochemical sensing, further expanding its application prospects.

[0073] Example 1 A preparation (synthesis) method of a carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material (COFs): Add phloroglucinol trialdehyde (TP, 10.5 mg) and symmetric indacene-1, 3, 5, 7(2H, 6H)-tetrone (16.1 mg) to a mixed solvent of 1.0 mL of o-dichlorobenzene and n-butanol with a volume ratio of 3:7. Then add 0.1 mL of 12 mol / L acetic acid aqueous solution as a catalyst, sonicate for 10 min, and then cycle through the liquid nitrogen freezing-thawing process 3 times, where the liquid nitrogen freezing time is 5 min and the thawing time is 7 min. After reacting in a forced-air drying oven at 120 °C for 72 h, filter and wash with N,N-dimethylformamide and tetrahydrofuran, and vacuum dry at 100 °C for 24 h to obtain a black powder TPTTCOF product with a yield of 93%.

[0074] Example 2 The difference between this example and Example 1 is that the reaction time is extended to 96 h, and the yield is 90%. Other steps in this example are the same as those in Example 1.

[0075] Example 3 The difference between this example and Example 1 is that the reaction time is shortened to 48 h, and the yield is 85%. Other steps in this example are the same as those in Example 1. Other steps in this example are the same as those in Example 1.

[0076] Example 4 The difference between this example and Example 1 is that the reaction temperature is 160 °C, and the yield is 90%. Other steps in this example are the same as those in Example 1.

[0077] Example 5 The difference between this example and Example 1 is that the reaction temperature is 80 °C, and the yield is 78%. Other steps in this example are the same as those in Example 1.

[0078] Example 6 The difference between this example and Example 1 is that the volume ratio of phloroglucinol to symmetric indacene-1, 3, 5, 7(2H, 6H)-tetrone is 1:1 (1.0 mL), and the yield is 86%. Other steps in this example are the same as those in Example 1.

[0079] Example 7 The difference between this example and Example 1 is that the volume ratio of phloroglucinol to symmetric indacene-1, 3, 5, 7(2H, 6H)-tetrone is 1:3 (1.0 mL), and the yield is 88%. Other steps in this example are the same as those in Example 1.

[0080] Example 8 The difference between this example and Example 1 is that 0.1 mL of 9M aqueous acetic acid solution is added as a catalyst, and the yield is 84%. Other steps in this example are the same as those in Example 1.

[0081] Example 9 The difference between this example and Example 1 is that 0.1 mL of 15M aqueous acetic acid solution is added as a catalyst, and the yield is 91%. Other steps in this example are the same as those in Example 1.

[0082] Example 10 The difference between this example and Example 1 is that 0.2 mL of 12M aqueous acetic acid solution is added as a catalyst, and the yield is 92%. Other steps in this example are the same as those in Example 1.

[0083] Analysis and Verification Taking Example 1 as an example, the TPTTCOF material was analyzed: As Figure 2 shown, Figure 2 The PXRD pattern of the TPTTCOF synthesized in Example 1 is shown. Through PXRD testing, strong diffraction peaks can be seen at about 4.86°, 6.94°, and 27.58°, which confirms that the organic material has good crystallinity and it can be judged that the pore size is in the micropore range.

[0084] As Figure 3 shown, Figure 3 The infrared absorption spectrum of the synthesized TPTTCOF is shown. The peak at 1703 cm 1 is attributed to the characteristic stretching vibration absorption of the C=O bond at each unit connection of TPTTCOF, and the peak at 3440 cm 1 is attributed to the characteristic stretching vibration absorption of the OH bond. At the same time, the presence of the characteristic stretching vibration absorption peak of the C=C bond at 1625 cm 1 further proves the successful synthesis of the TPTTCOF material.

[0085] As Figure 4As shown Figure 4 is the solid C NMR spectrum of TPTTCOF 13 The carbonyl group on the aryl ring of TPTTCOF shows a chemical shift at 190.4 ppm. The carbon signals at 171.5 and 106.4 ppm are attributed to the benzene rings of the conjugated linkers, which further prove the structural correctness and effectiveness of the synthesized material.

[0086] As Figure 5 shown Figure 5 is the SEM image of the synthesized COFs. The SEM data shows that TPTTCOF has a uniform fibrous morphology at the 200 nm scale.

[0087] As Figure 6 and Figure 7 shown Figure 6 is the N2 adsorption-desorption test of TPTTCOF. Both curves have a gentle slope, a high saturation adsorption capacity, and a high degree of curve overlap, indicating that TPTTCOF has good adsorption capacity. During the adsorption-desorption process, the material has good symmetry and reversibility, and stable performance. In addition, the high degree of overlap also represents that the pore structure and size of the material are relatively uniform, and the specific surface area is 199.7 m 2 g 1 . Figure 7 is the pore size distribution diagram of TPTTCOF. The micropores of the material are mainly distributed between 1.2 and 1.8 nm, concentrated around 1.4 nm, and this result is consistent with the pore size of the chemical structure formula of the material.

[0088] The TPTTCOF in Example 1 was used to modify the zinc metal surface, and the performance of AZIBs was experimentally analyzed. The experimental steps are as follows: TPTTCOF (24 mg) was fully mixed with polyvinylidene fluoride (6 mg), and N-methylpyrrolidone was added to prepare a uniform slurry. The slurry was coated on the surface of zinc foil by the doctor blade method and dried in an oven at 80 °C for 12 h. The TPTTCOF@Zn was cut into a disc with a diameter of 8 mm to assemble a symmetric button-type AZIBs. Among them, the separator used Whatman GF / D glass microfiber filter paper, and the electrolyte was 2 mol / L zinc sulfate aqueous solution.

[0089] The cyclic performance of the zinc metal anode of AZIBs modified with TPTTCOF provided in the embodiment of the present invention. After being modified with TPTTCOF, the zinc anode has a smaller overpotential and a longer cycle life. At 2 mA / cm 2At the current density, the overpotential of TPTTCOF@Zn is 30 mV. After 200 h of cycling, the zinc metal electrode still maintains good stability. While for the pristine zinc anode without TPTTCOF modification, its overpotential reaches 400 mV at the same current density, and it short-circuits after 15 h of cycling due to the growth of zinc dendrites. Therefore, this material can effectively serve as a modification material for zinc metal anodes, regulating the transport and deposition of charge carriers on the electrode surface, and has potential application value in fields such as AZIBs.

[0091] The technical solution of the present invention solves the problems of severe polarization and short cycle life of the zinc metal anode in AZIBs due to dendrite growth and side reactions. At the same time, it also solves the drawback that other surface modification layer methods cannot kinetically regulate the transport and deposition behaviors of charge carriers. This is a kind of organic porous material with great application prospects for modifying the zinc metal anode in AZIBs.

[0092] Although the present invention has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A carbonyl- and hydroxyl-rich DA-type covalent organic framework TPTTCOF material, characterized in that, The structural formula of the TPTTCOF material is as follows: 。 2. The D-A type covalent organic framework TPTT-COF material rich in carbonyl and hydroxyl groups as described in claim 1, wherein, This material is formed by the Knoevenagel condensation reaction of phloroglucinol trialdehyde (TP) and symmetric indacene-1,3,5,7(2H,6H)-tetrone. Its molecular structure contains a benzene ring skeleton and has carbonyl (C=O) and hydroxyl (-OH) functional groups. The uniform distribution of carbonyl and hydroxyl groups provides a donor-acceptor (D-A) conjugated structure, making it have excellent application performance in the fields of electrochemical energy storage, catalysis, and molecular adsorption.

3. The TPTT-COF material according to claim 1, wherein This material has a high specific surface area and a porous structure with adjustable pore size, good crystallinity, and can be applied in the fields of anode materials for aqueous zinc-ion batteries, electrode materials for supercapacitors, catalyst carriers, and gas adsorption and separation.

4. A preparation method of a D-A type covalent organic framework TPTT-COF material rich in carbonyl and hydroxyl groups, characterized in that, It includes the following steps: Step 1: Add phloroglucinol trialdehyde and symmetric indacene-1,3,5,7(2H,6H)-tetrone into a mixed solvent, and then add a catalyst; Step 2: Perform ultrasonic treatment on the mixed solution; Step 3: Use liquid nitrogen as a refrigerant for vacuum freeze-thaw cycles; Step 4: Carry out a heating reaction. After the reaction is completed, wash and vacuum dry to obtain the TPTT-COF material.

5. The preparation method according to claim 4, characterized in that, The mixed solvent includes ortho-dichlorobenzene and n-butanol with a volume ratio of 1:1 to 10, and the total mass of monomers dispersed in every 10 mL of the mixed solvent is 0.1 to 1 g.

6. The preparation method according to claim 4, characterized in that, The catalyst is an aqueous acetic acid solution with a concentration of 2 to 15 mol / L, and the volume ratio of the catalyst to the mixed solvent is 1:2 to 20.

7. The preparation method according to claim 4, characterized in that, The ultrasonic treatment time in Step 2 is 1 to 15 min.

8. The preparation method according to claim 4, wherein The liquid nitrogen freezing and thawing time in Step 3 is 1 to 10 min.

9. The preparation method according to claim 4, characterized in that, The heating reaction temperature in Step 4 is 80 to 160 °C, the heating reaction time is 12 to 96 h, and the reaction product is washed with N,N-dimethylformamide and tetrahydrofuran. For every 1 mmol of reactant, 5 to 50 mL of N,N-dimethylformamide and 1 to 10 mL of tetrahydrofuran are used.

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