Method for preparing functional electrode through surface in-situ carbene polymerization and application thereof
In-situ carbene polymerization using azide compounds on metal electrodes addresses the non-uniformity and impurity issues of existing polymer surface modifications, resulting in a stable and functionalized polymer film with enhanced electrochemical performance.
Patent Information
- Application Number
- CN202510635088.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-16
- Publication Date
- 2025-07-15
AI Technical Summary
In the prior art, polymer materials have uneven distribution of polymers on the electrode surface modification method and poor controllability of film thickness, making it difficult to achieve molecular-level functional design. In addition, impurities are easily introduced in multi-step processes, affecting the stability and reliability of the electrode.
Diazo compounds are used as monomers to undergo in-situ carbene polymerization reaction with the metal electrode, forming a uniform and dense polymer film on the electrode surface, and covalently bonded to the electrode surface through C-M chemical bonds to construct a polymer film with adjustable functions.
The uniform distribution and stability of polymer films are achieved, the electrolytic performance of the electrodes is improved, and the operation steps are simplified. It is suitable for various metal electrodes, especially planar and porous electrodes.
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Figure CN120311224A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of electrochemical energy materials and devices, and particularly relates to a method for preparing a functional electrode through a surface in-situ carbene polymerization reaction, and the application of the electrode in an electrolysis device. Background Art
[0002] With the continuous growth of energy demand and the increasingly prominent environmental problems, the global energy structure is transforming towards cleaner and lower-carbon forms. The development of electrochemical energy devices (such as carbon dioxide electroreduction devices, water electrolysis hydrogen production devices, fuel cells, etc.) has become a key breakthrough point in clean energy technology. As the core component of electrochemical energy devices, the performance of the electrode directly affects the efficiency and stability of the entire device.
[0003] Currently, researchers are committed to improving the performance of electrodes through surface modification methods and have made certain progress. Among them, modifying the electrode surface with polymer materials has certain advantages. Due to its high molecular weight characteristics, polymer materials are not easily lost under electrolysis conditions, are more stable, and can effectively prevent shedding, which is crucial for maintaining the long-term stability of the electrode interface environment. In the prior art, common polymer surface modification methods include physical coating such as spraying, drop coating, spin coating on the electrode surface, and electrochemical deposition methods. However, since polymers are difficult to completely dissolve in solvents and exist in the form of dispersed particles, it is difficult to uniformly cover the electrode surface, resulting in a series of problems such as uneven polymer distribution and poor controllability of the film thickness, which in turn affects the mass transfer efficiency and reduces the reaction activity. In addition, the ability to precisely control the surface structure is limited, it is difficult to achieve molecular-level functional design, and multi-step processes are prone to introducing impurities, affecting the reliability of the electrode. Therefore, developing new electrode surface polymer modification methods to improve electrolysis performance is of great significance. Summary of the Invention
[0004] Provide a method for preparing a functional electrode by surface in-situ carbene polymerization. Using a diazo compound as a monomer, it reacts with a metal electrode to form a C-M (carbon-metal bond) chemical bond, and directly generates a polymer film on the surface of the metal electrode. That is, through the in-situ polymerization reaction of the diazo compound on the surface of the metal electrode, a uniform, dense and function-tunable polymer film is constructed to improve the performance of the electrode in the electrolysis device.
[0005] To achieve the above object, the present invention provides a method for preparing a functional electrode by surface in-situ carbene polymerization, which is characterized by including the following steps: Step 1, prepare a reaction solution containing a diazo compound monomer; Step 2, place the metal electrode in the reaction solution, and form a polymer film on the electrode surface through an in-situ carbene polymerization reaction; Step 3, wash and dry to obtain a functional electrode. Further, the diazo compound monomer includes aryl diazonium salts, alkyl diazo esters or diazo amide compounds. The aryl diazonium salts can be one or more of methoxybenzene diazonium tetrafluoroborate, phenyl diazonium tetrafluoroborate, p-nitrobenzene diazonium tetrafluoroborate, p-chlorobenzene diazonium tetrafluoroborate; the alkyl diazo esters can be one or more of methyl diazoacetate, ethyl diazoacetate, tert-butyl diazoacetate, ethyl diazopropionate, ethyl methyl diazobutyrate, trimethylsilyl diazomethane; the diazo amide compounds can be one or more of diazoacetamide, N-methyl diazoacetamide, diazopropionamide, N-phenyl diazoacetamide, indolyl diazoacetamide.
[0006] Further, the solvent is one or more of acetonitrile, ether or N, N-dimethylformamide.
[0007] Further, the metal electrode includes planar electrodes such as Cu, Au, Ag or complex porous structure electrodes such as gas diffusion electrodes.
[0008] Further, the in-situ polymerization reaction time is from 10 minutes to 24 hours, and the reaction time is determined according to the activity of the diazo compound monomer and the thickness of the polymer film to be constructed.
[0009] The present invention also provides a functional electrode prepared by the above method, characterized in that the thickness of the polymer film on the electrode surface is 50 nm to 5 μm and is uniform and dense.
[0010] Further, the polymer film is covalently bonded to the electrode surface through a carbon-metal bond.
[0011] On the other hand, the present invention also provides an electrolytic device, characterized in that it includes the above-mentioned functional electrode as a working electrode.
[0012] Further, the electrolytic device is an electrocatalytic carbon dioxide reduction device, an electrolytic water hydrogen production device or a fuel cell, etc.
[0013] The present invention also provides the application of the functional electrode as described above in the electrocatalytic carbon dioxide reduction reaction.
[0014] Beneficial effects (1) There are many types of diazo compound monomers. The types and physical distributions of the functional groups of the polymer film can be further regulated by polymerizing different diazo compound monomers with the electrode and controlling the polymerization reaction time and concentration, so as to realize the functionalization of the surface polymer microenvironment and avoid problems such as uneven polymer distribution and poor film controllability.
[0015] (2) A covalent bond is formed in-situ on the electrode surface and a polymer network is constructed directionally, and the surface polymer film is more stable and not easy to fall off.
[0016] (3) The in-situ carbene polymerization method is simple to operate, without the need for complex equipment and cumbersome procedures, and has good practicability and operability.
[0017] (4) The in-situ carbene polymerization method has wide applicability and can be used for various metal electrodes such as planar electrodes and porous electrodes. Description of the Drawings
[0018] Figure 1 It is a scanning electron microscope image after in-situ carbene polymerization on the surface of Cu foil with p-methoxyphenyldiazonium tetrafluoroborate as the monomer in Example 1; Figure 2 It is the electrocatalytic carbon dioxide reduction performance after in-situ carbene polymerization on the surface of Cu foil with p-methoxyphenyldiazonium tetrafluoroborate as the monomer in Example 1; Figure 3 It is the electrocatalytic carbon dioxide reduction performance after in-situ carbene polymerization on the surface of Cu gas diffusion electrode with p-methoxyphenyldiazonium tetrafluoroborate as the monomer in Example 2; Figure 4 It is a scanning electron microscope image after in-situ carbene polymerization on the surface of Cu foil with ethyl diazoacetate as the monomer in Example 3; Figure 5 It is the electrocatalytic carbon dioxide reduction performance after in-situ carbene polymerization on the surface of Cu foil with ethyl diazoacetate as the monomer in Example 3. Detailed Embodiments
[0019] The present application will be further described in detail below. It is necessary to point out here that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the protection scope of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.
[0020] Example 1 In this example, p-methoxyphenyldiazonium tetrafluoroborate is used as the monomer, and a functional Cu electrode sheet is obtained by in-situ carbene polymerization on the surface of Cu foil, which specifically includes the following steps: (1) Cut a 2 cm × 2 cm Cu foil, and successively clean it with deionized water, acetone, and ethanol and ultrasonicate each for 3 minutes to obtain a Cu electrode sheet.
[0021] (2) Preparation of the reaction solution: Dissolve 0.2 mmol of p-methoxyphenyldiazonium tetrafluoroborate in 12 ml of acetonitrile to obtain a reaction salt solution.
[0022] (3) Put the pretreated Cu electrode sheet into the above reaction solution, let it stand and react at room temperature for 1 hour, then take it out, wash it with acetonitrile and dry it in vacuum. Through this process, a uniform and dense polymer film is covered on the surface of the Cu electrode sheet.
[0023] (4) Finally, an H-type cell is used to evaluate the electrocatalytic carbon dioxide reduction performance. The working electrode is the Cu electrode sheet after in-situ carbene polymerization on the surface prepared in this example. The counter electrode is a platinum sheet, and the reference electrode is Hg / Hg2SO4. A capillary salt bridge is connected to control the electrode potential of the cathode. The electrolyte is 0.1 M KHCO3, and the cathode chamber is continuously purged with carbon dioxide at a flow rate of 5 sccm.
[0024] The surface morphology of the Cu electrode sheet after in-situ carbene polymerization prepared in the embodiment of the present invention is as Figure 1 shown. A uniform and dense polymer film covers the surface of the Cu electrode sheet. The electrocatalytic carbon dioxide reduction performance of the Cu electrode sheet after in-situ carbene polymerization in this example in the H-type cell is as Figure 2 shown. A Faraday efficiency of approximately 43% for ethylene is achieved at -1.3 V vs RHE, and a high Faraday efficiency for ethylene is maintained in the potential range of -1.1 V to -1.4 V vs RHE. Compared with the blank Cu, the selectivity for ethylene is increased by 30%.
[0025] Example 2 In this example, p-methoxyphenyldiazonium tetrafluoroborate is used as the monomer, and a functional Cu electrode is obtained by in-situ carbene polymerization on the surface of a Cu gas diffusion electrode, which specifically includes the following steps: (1) High-purity Cu is deposited on a carbon paper substrate by magnetron sputtering technology, and a 2 cm × 2 cm Cu gas diffusion electrode is cut.
[0026] (2) Preparation of the reaction solution: 0.1 mmol of p-methoxyphenyldiazonium tetrafluoroborate is dissolved in 12 ml of acetonitrile to obtain a reaction salt solution.
[0027] (3) The pretreated Cu gas diffusion electrode is placed in the above reaction solution, taken out after standing for reaction at room temperature for 10 minutes, washed with acetonitrile and dried in vacuum. Through this process, a uniform and dense polymer film covers the surface of the Cu gas diffusion electrode.
[0028] (4) Finally, a flow cell is used to evaluate the electrocatalytic carbon dioxide reduction performance. The working electrode is the Cu gas diffusion electrode after in-situ carbene polymerization on the surface prepared in this example. The counter electrode is an IrO2 electrode sheet, and the reference electrode is Hg / Hg2SO4. A capillary salt bridge is connected to control the electrode potential of the cathode. The electrolyte is 0.5 M KHCO3, and the cathode chamber is continuously purged with carbon dioxide at a flow rate of 20 sccm.
[0029] The electrocatalytic carbon dioxide reduction performance of the Cu gas diffusion electrode after in-situ carbene polymerization in the embodiment of the present invention in the flow cell is as Figure 3As shown, the Faradaic efficiency of ethylene is about 50% at -1.1 V vs RHE, and the total current density is about 740 mA cm at -1.3 V vs RHE. -2 The electrocatalytic carbon dioxide reduction performance remains excellent at high currents, promoting C 2+ product selectivity.
[0030] Example 3 In this example, ethyl diazoacetate was used as the monomer, and a functional Cu electrode sheet was obtained by in-situ carbene polymerization on the surface of a Cu foil. The specific steps are as follows: (1) Cut a 2 cm × 2 cm Cu foil, and wash it successively with deionized water, acetone, and ethanol, and ultrasonicate each for 3 minutes to obtain a Cu electrode sheet.
[0031] (2) Place the pretreated Cu electrode sheet into the ethyl diazoacetate solution, let it stand and react at room temperature for 24 hours, then take it out, wash it with ether, and dry it under vacuum.
[0032] (3) Finally, use an H-type cell to evaluate the electrocatalytic carbon dioxide reduction performance. The working electrode is the Cu electrode sheet obtained by in-situ carbene polymerization on the surface in this example, the counter electrode is a platinum sheet, the reference electrode is Hg / Hg2SO4, and a capillary salt bridge is connected to control the electrode potential of the cathode. The electrolyte is 0.1 M KHCO3, and the cathode chamber is continuously purged with carbon dioxide at a flow rate of 5 sccm.
[0033] The surface morphology of the Cu electrode sheet obtained by in-situ carbene polymerization on the surface in the embodiment of the present invention is as Figure 4 shown, and the surface of the Cu electrode sheet is covered with a polymer. The electrocatalytic carbon dioxide reduction performance of the Cu electrode sheet after in-situ carbene polymerization in this example in the H-type cell is as Figure 5 shown. The Faradaic efficiency of methane reaches about 65% at -1.4 V vs RHE. Compared with the blank Cu, the methane selectivity is increased by about 20%.
[0034] Example 4 In this example, ethyl diazoacetate was used as the monomer, and a functional Ag electrode sheet was obtained by in-situ carbene polymerization on the surface of an Ag foil. The specific steps are as follows: (1) Cut a 2 cm × 2 cm Ag foil, and wash it successively with deionized water, acetone, and ethanol, and ultrasonicate each for 3 minutes to obtain an Ag electrode sheet.
[0035] (2) Place the pretreated Ag electrode sheet into the ethyl diazoacetate solution, let it stand and react at room temperature for 24 hours, then take it out, wash it with ether, and dry it under vacuum.
[0036] (3)Finally, an H-type cell was used to evaluate the electrocatalytic carbon dioxide reduction performance. The working electrode was the Ag electrode sheet obtained by in-situ carbene polymerization on the surface prepared in this example. The counter electrode was a platinum sheet, and the reference electrode was Hg / Hg2SO4. A capillary salt bridge was connected to control the electrode potential of the cathode. The electrolyte was 0.1 M KHCO3, and the cathode chamber was continuously purged with carbon dioxide at a flow rate of 5 sccm.
[0037] In the example of the present invention, in-situ carbene polymerization was successfully carried out on the Ag electrode sheet. The Faraday efficiency of electrocatalytic reduction of carbon dioxide to carbon monoxide in the H-type cell was relatively excellent.
[0038] Comparative Example 1 In this comparative example, a blank Cu electrode sheet was obtained by pretreating a Cu foil under the same conditions as in Example 1 above, specifically including the following steps: (1) A 2 cm×2 cm Cu foil was cut, and successively washed with deionized water, acetone, and ethanol and ultrasonically treated for 3 minutes each to obtain a Cu electrode sheet.
[0039] (2) The pretreated Cu electrode sheet was placed in a pure acetonitrile solvent and left to stand at room temperature for 1 hour, then taken out, washed with acetonitrile, and dried under vacuum.
[0040] (3) Finally, an H-type cell was used to evaluate the electrocatalytic carbon dioxide reduction performance. The working electrode was the blank Cu electrode sheet of this comparative example, the counter electrode was a platinum sheet, and the reference electrode was Hg / Hg2SO4. A capillary salt bridge was connected to control the electrode potential of the cathode. The electrolyte was 0.1 M KHCO3, and the cathode chamber was continuously purged with carbon dioxide at a flow rate of 5 sccm.
[0041] In Comparative Example 1, the electrocatalytic carbon dioxide reduction performance of the blank Cu electrode sheet in the H-type cell was such that the Faraday efficiency of ethylene was only about 13% and that of methane was only about 48% at -1.4 V vs RHE at most.
[0042] Comparative Example 2 In this comparative example, poly(p-benzoquinone) was used as a monomer and directly drop-coated on the surface of a Cu foil to obtain a functional Cu electrode sheet, specifically including the following steps: (1) A 2 cm×2 cm Cu foil was cut, and successively washed with deionized water, acetone, and ethanol and ultrasonically treated for 3 minutes each to obtain a Cu electrode sheet.
[0043] (2) Poly(p-benzoquinone) molecules were dissolved in N,N-dimethylformamide. After being dispersed by ultrasound, the mixed solution was drop-coated on the Cu electrode sheet and dried in a vacuum drying oven.
[0044] (3)Finally, an H-type cell was used to evaluate the electrocatalytic carbon dioxide reduction performance. The working electrode was the Cu electrode sheet modified with surface polymer prepared in this comparative example, the counter electrode was a platinum sheet, and the reference electrode was Hg / Hg2SO4. A capillary salt bridge was connected to control the electrode potential of the cathode. The electrolyte was 0.1 M KHCO3, and the cathode chamber was continuously purged with carbon dioxide at a flow rate of 5 sccm.
[0045] In this comparative example 2, the Faraday efficiency of electrocatalytic reduction of carbon dioxide to ethylene in the H-type cell was only about 20% at most at -1.4 V vs RHE. At this potential, the total current density was relatively low, only about 20 mA cm -2 . And the selectivity of ethylene was lower than 20% in the potential range of -1.0 V to -1.2 V vs RHE.
[0046] The above specific embodiments are only used to illustrate the technical solutions of the present invention and are not limited to the above specific embodiments. Those skilled in the relevant art can make corresponding changes or adjustments within the scope of the claims, and all are within the scope of protection of the claims of the present invention.
Claims
1. A method for preparing a functional electrode by surface in-situ carbene polymerization, characterized in that, It includes the following steps: Step 1: Prepare a reaction solution containing a diazo compound monomer; Step 2: Place a metal electrode in the reaction solution and form a polymer film on the electrode surface through an in-situ carbene polymerization reaction; Step 3: Clean and dry to obtain a functional electrode.
2. The method according to claim 1, wherein The diazo compound monomer is one or several of aryl diazonium salts, alkyl diazo esters or diazoamide compounds.
3. The method according to claim 1, wherein The solvent is one or several of acetonitrile, diethyl ether or N,N-dimethylformamide.
4. The method according to claim 1, wherein The metal electrode includes a Cu, Au, Ag planar electrode or a complex porous structure electrode such as a gas diffusion electrode.
5. The method according to claim 1, characterized in that The in-situ polymerization reaction time is 10 minutes to 24 hours.
6. The functional electrode prepared by the method according to claims 1-5, characterized in that, The thickness of the polymer film on the electrode surface is 50 nm to 5 μm, and it is uniform and dense.
7. The functional electrode according to claim 1, wherein The polymer film is covalently bonded to the electrode surface through a carbon-metal bond.
8. An electrolytic device, characterized in that, It includes the functional electrode described in claims 6-7 as the working electrode.
9. The electrolytic device according to claim 8, characterized in that, The electrolysis device is an electrocatalytic carbon dioxide reduction device, an electrolytic water hydrogen production device or a fuel cell, etc.
10. Use of the functional electrode described in claims 6-7 in an electrolysis device.