Metal electrode plate based on hydrogel material and preparation method and application thereof

Abstract

The invention discloses a metal electrode plate based on a hydrogel material and a preparation method and application thereof, and belongs to the field of interface modification. The surface of the metal electrode plate is provided with an active carboxy-based layer, and nano hydrogel particles containing amino groups are loaded on the active carboxy-based layer; the preparation method comprises the following steps: soaking a metal electrode plate with an active carboxyl layer in a dispersion liquid of nano hydrogel particles containing amino groups, and connecting the nano hydrogel particles to the surface of the metal electrode plate through covalent bonds by virtue of a dehydration condensation reaction, so as to complete loading of the nano hydrogel particles, the obtained metal electrode plate can be used in the field of alkaline electro-catalysis hydrogen evolution. The nano hydrogel particles are attached to the surface of the metal electrode plate, the electro-catalytic performance is obviously improved compared with that of a pure electrode, and experimental data shows that the overpotential can be reduced by 60 mV at the maximum under the current density of 100 mA / cm < 2 >, so that the water structure of the alkaline electro-catalytic hydrogen evolution HER reaction surface is modified.

Description

Technical Field

[0001] The invention belongs to the technical field of interface modification, and in particular relates to a metal electrode sheet based on a hydrogel material, and a preparation method and application thereof. Background Art

[0002] Hydrogen has attracted extensive attention from the international community due to its advantages such as zero pollution, recyclable production and high combustion rate. Among the many hydrogen production methods, the hydrogen evolution reaction (HER) has the advantages of simple equipment, sustainability and environmental protection.

[0003] Existing studies have explained the process of acidic HER. Based on the adsorption behavior of hydrogen intermediates (H*, representing active sites) on a variety of catalysts, the reaction of acidic HER can be accurately explained and predicted. Current studies have shown that the reaction kinetics of HER in alkaline environments are two to three orders of magnitude slower than those in acidic electrolytes. Studies have shown that in acidic HER, H* comes from H in the electrolyte. + , while in alkaline HER, H* comes from water dissociation ( ), and the additional energy barrier introduced by water dissociation is the reason for the slow HER kinetics in alkaline environment.

[0004] Current research suggests that the orientation of water in the double-electron layer EDL and the "network" structure of water are the main factors affecting the catalytic rate. Water "orientation" research suggests that changes in water orientation in the double-electron layer will lead to more energy consumption; water "network" research suggests that water in the double-electron layer forms a water network through hydrogen bonds, and this hydrogen bond network will be disturbed by charge transfer during the HER process. The destruction and reconstruction of the water network during the charge transfer process will lead to more energy consumption.

[0005] Therefore, how to regulate the water orientation and water structure in alkaline HER is a technical problem that needs to be solved at present. Summary of the invention

[0006] Purpose of the invention: The first purpose of the present invention is to provide a metal electrode sheet based on a hydrogel material that can change the water structure on an alkaline hydrogen evolution reaction surface and thereby reduce the reaction energy barrier and the difficulty of the reaction. The second purpose of the present invention is to provide a method for preparing the above-mentioned metal electrode sheet based on a hydrogel material. The third purpose of the present invention is to provide an application of the above-mentioned metal electrode sheet based on a hydrogel material.

[0007] Technical solution: The surface of the metal electrode sheet based on the hydrogel material described in the present invention has an active carboxyl layer, and the active carboxyl layer is loaded with nano hydrogel particles containing amino groups.

[0008] Furthermore, the metal electrode sheet is Pt, Ni, or Pd, and the particle size of the nano-hydrogel particles is less than 500 nm.

[0009] The above-mentioned method for preparing the metal electrode sheet based on the hydrogel material comprises the following steps:

[0010] (1) Carboxylating the metal electrode sheet to obtain a metal electrode sheet having an active carboxyl layer;

[0011] (2) preparing a dispersion of nano-hydrogel particles containing amino groups;

[0012] (3) The metal electrode sheet with an active carboxyl group is immersed in a dispersion of nano-hydrogel particles containing amino groups, and the nano-hydrogel particles are connected to the surface of the metal electrode sheet by covalent bonds through a dehydration condensation reaction. The nano-hydrogel particle loading is completed to obtain a metal electrode sheet based on a hydrogel material.

[0013] Furthermore, in step (1), the carboxylation step is:

[0014] (11) placing the metal electrode sheet after surface cleaning in an alcohol solution containing a thiol compound and fully immersing it, then taking it out and rinsing it;

[0015] (12) The rinsed metal electrode sheet is placed in a mixed aqueous solution containing 2-(N-morpholine)ethanesulfonic acid, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide and fully immersed, and then taken out after the end.

[0016] Furthermore, in step (11), the molar concentration of the thiol compound in the alcohol solution is 0.01-0.02 mol / L, and the immersion time is 2-4 h; in step (12), in the mixed aqueous solution, the molar concentration of 2-(N-morpholine)ethanesulfonic acid is 0.001-0.002 mol / L, the molar concentration of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 0.002-0.003 mol / L, the molar concentration of N-hydroxysuccinimide is 0.005-0.006 mol / L, and the immersion time is 24 h-48 h.

[0017] Furthermore, in step (2), the preparation steps of the dispersion of the nano hydrogel particles containing amino groups are:

[0018] (21) dissolving the active agent and the initiator in an organic solvent and mixing them to obtain an organic phase solution;

[0019] (22) dissolving an ethylenic monomer, allylamine, and a cross-linking agent in water and mixing to obtain an aqueous solution;

[0020] (23) The aqueous phase solution is added to the organic phase solution, ultrasonically dispersed, and deoxygenated after being fully dispersed. The solution is then stirred in a water bath, demulsified, allowed to stand, and centrifuged. The lower precipitate is removed, repeatedly washed, and mixed with a buffer solution to obtain a dispersion of nano-hydrogel particles containing amino groups.

[0021] Furthermore, in step (21), the amount ratio of the active agent, the initiator and the organic solvent is 9.18-10g:24mg:120-200mL, the active agent includes Tween 80 and Span 80, and the initiator is azobisisobutyl cyanide; in step (22), the amount ratio of the polymer monomer, allylamine, the crosslinking agent and water is 0.02-0.025mol:84.2mg:13.8mg:1.5-2mL; the polymer monomer is an olefinic monomer or a combination of an olefinic monomer and a functional monomer for enhancing hydrophobic properties; the crosslinking agent is N,N′-methylenebisacrylamide; in step (23), the parameters of the ultrasonic dispersion are: ultrasonication at below 40°C for 1-2h; the parameters of the water bath stirring are: stirring at 40-50°C for 24-28h; the reagent used for the demulsification treatment is tetrahydrofuran, and the buffer is 0.01-0.02moL / L phosphate buffer.

[0022] Preferably, the polymer monomer is a combination of an olefinic monomer and a functional monomer for enhancing hydrophobic properties, and the molar ratio of the olefinic monomer to the functional monomer for enhancing hydrophobic properties is 1:3.5-4.5.

[0023] More preferably, the olefinic monomer is [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide, and the functional monomer is vinyl triethoxysilane or octadecyl methyl vinyl ester.

[0024] Furthermore, in step (3), the conditions of the dehydration condensation reaction are: reacting at 40-50° C. for 24-30 hours.

[0025] The application of the above-mentioned metal electrode sheet based on hydrogel material in the field of alkaline electrocatalytic hydrogen evolution.

[0026] Principle of the invention: The present invention uses hydrogel attachment as a method to regulate the interfacial water configuration, and innovatively connects nano-hydrogel particles to metal electrodes by covalent bonds. Hydrogel is a type of three-dimensional network structure gel that has a strong interaction with water, and its strong interaction with water may cause a huge change in the structure of water molecules. In addition, nano-scale hydrogel particles are attached to the surface of the electrode sheet. Since the nano-hydrogel particles are very small and are just in the double-electron layer EDL region, the orientation of water molecules in the double-electron layer region and the hydrogen bond network structure between water molecules can be effectively changed, thereby affecting the electrocatalytic rate.

[0027] Beneficial effects: Compared with the prior art, the present invention has the following significant effects: (1) The preparation process of nano-hydrogel particles is mature and simple, with high raw material utilization and environmental friendliness, and the preparation process will not cause environmental pollution and large-scale emission of harmful substances; (2) The method involved in the present invention has a certain universality, and is not targeted at a specific electrode sheet, but is a universal method for reducing the reaction overpotential and improving the electrocatalytic performance of all hydrogen-evolving metal electrode sheets (such as Pt, Ni, Pd, etc.); (3) The present invention significantly improves the HER performance of the metal electrode sheet and effectively reduces the reaction overpotential. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a SEM image of a platinum metal electrode sheet based on a hydrogel material prepared in Example 1;

[0029] Figure 2 This is an enlarged SEM image of the amphiphilic nano-hydrogel particles in the platinum metal electrode sheet based on the hydrogel material prepared in Example 1;

[0030] Figure 3 This is a comparison chart of the LSV performance of the platinum metal electrode sheet based on the hydrogel material prepared in Example 1 and the pure platinum electrode in Comparative Example 1;

[0031] Figure 4 This is a comparison chart of the LSV performance of the platinum metal electrode sheet based on the hydrogel material prepared in Example 2 and the pure platinum electrode in Comparative Example 1;

[0032] Figure 5 This is a comparison chart of the LSV performance of the platinum metal electrode sheet based on the hydrogel material prepared in Example 3 and the pure platinum electrode in Comparative Example 1;

[0033] Figure 6 This is a comparison chart of the LSV performance of the platinum metal electrode sheets prepared in Comparative Examples 1 to 3. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below in conjunction with the embodiments and drawings.

[0035] Example 1: The surface of the platinum metal electrode sheet based on the hydrogel material provided in this example has an active carboxyl layer, and the active carboxyl layer is loaded with amphiphilic nano-hydrogel particles containing amino groups;

[0036] The preparation steps are:

[0037] 1) Pretreatment of metal electrode sheets

[0038] Cut out a 10mm×10mm platinum metal electrode sheet, use anhydrous ethanol, acetone, 0.1mol / L dilute hydrochloric acid and deionized water to ultrasonically clean the metal electrode sheet to remove the metal oxide, oil and other impurities on the surface. Then, soak it in 0.01mol / L 6-mercaptohexanoic acid alcohol solution for 2-4h at room temperature, and after it is fully soaked for a sufficient time, rinse it with anhydrous ethanol, and transfer the rinsed electrode sheet to a mixed aqueous solution of 0.001mol / L 2-(N-morpholine)ethanesulfonic acid (MES), 0.002mol / L 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC·HCL) and 0.005mol / L N-hydroxysuccinimide (NHS) at room temperature, soak it for 24h and then take it out. Through the above pretreatment process, a platinum metal electrode sheet with active carboxyl groups (-COOH) (i.e., active carboxyl groups) connected to the surface is obtained.

[0039] 2) Preparation of Nanohydrogel Particles

[0040] Take 4.26g Tween 80, 4.92g Span 80 and 24mg initiator azobisisobutyl cyanide (AIBN) and dissolve them in 120mL n-hexane, put them into a 250mL three-necked flask and stir them evenly to obtain an organic phase solution for use. Then take 586.6mg [2-(methacryloyloxy)ethyl] dimethyl-(3-sulfonic acid propyl) ammonium hydroxide (DMAPS), 84.2mg allylamine (AH), 13.8mg crosslinker N,N′-methylenebisacrylamide (MBA) and dissolve them in 1.5mL deionized water, stir and ultrasonicate them to fully dissolve them to obtain an aqueous phase solution. Then add the aqueous phase solution to the organic phase solution, and ultrasonicate for 1h while keeping the temperature below 40℃ to ensure that the aqueous phase solution is fully dispersed in the organic phase solution.

[0041] Then, argon inert gas was introduced into the part below the liquid level in the three-necked flask, and the gas was continuously ventilated for 40 minutes while bubbles continuously and evenly emerged to ensure that there was no oxygen inside the reactor and to ensure the smooth progress of the reaction. Then the bottle stopper was tightly sealed and stirred slowly for 24 hours at a water bath temperature of 40°C. Then 120mL of tetrahydrofuran (THF) was added to break the emulsion. After standing for 12 hours, the mixture was centrifuged at 4500rpm for 15 minutes, the lower precipitate was removed, and it was repeatedly washed with THF for 3-5 times. Finally, the lower precipitate was mixed with 60mL of 0.01moL / L phosphate buffer (PBS) to obtain a nanohydrogel particle dispersion.

[0042] 3) Preparation of metal electrode sheets loaded with nano-hydrogel particles

[0043] The platinum metal electrode sheet connected with active carboxyl groups (-COOH) obtained in step 1) is placed in the nano-hydrogel particle dispersion obtained in step 2) and immersed for 24 hours to allow -COOH on the surface of the metal electrode sheet and -NH2 on the surface of the hydrogel particles to undergo dehydration condensation reaction, and the nano-hydrogel particles are connected to the surface of the metal electrode sheet in the form of covalent bonds, thereby completing the loading of the hydrogel particles.

[0044] Comparative Example 1: A pure platinum electrode was used.

[0045] Example 2: The surface of the platinum metal electrode sheet based on the hydrogel material provided in this example has an active carboxyl layer, and the active carboxyl layer is loaded with nano-hydrogel particles containing amino groups and Si-O hydrophobic groups;

[0046] The preparation steps are:

[0047] 1) Pretreatment of metal electrode sheets

[0048] Cut out a 10mm×10mm platinum metal electrode sheet, and use anhydrous ethanol, acetone, 0.1mol / L dilute hydrochloric acid and deionized water to ultrasonically clean the metal electrode sheet to remove impurities such as metal oxides and oil stains on its surface. Then, soak it in 0.01mol / L 6-mercaptohexanoic acid alcohol solution for 2-4h at room temperature. After it is fully soaked for a sufficient time, rinse it with anhydrous ethanol, and transfer the rinsed electrode sheet to a mixed aqueous solution of 0.001mol / L 2-(N-morpholine)ethanesulfonic acid (MES), 0.002mol / L 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC·HCL) and 0.005mol / L N-hydroxysuccinimide (NHS) at room temperature, soak it for 24h and then take it out. Through the above pretreatment process, a platinum metal electrode sheet with active carboxyl (-COOH) connected on the surface is obtained.

[0049] 2) Preparation of Nanohydrogel Particles

[0050] Take 4.26g Tween 80, 4.92g Span 80 and 24mg initiator azobisisobutyl cyanide (AIBN) and dissolve them in 120mL n-hexane, put them into a 250mL three-necked flask and stir them evenly to obtain an organic phase solution for use. Then take 119.7mg [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide (DMAPS), 313.9mg vinyltriethoxysilane (N DMAPS :N 乙烯基三乙氧基硅烷=1:4), 84.2 mg of allylamine (AH), 13.8 mg of cross-linking agent N,N′-methylenebisacrylamide (MBA) were dissolved in 1.5 mL of deionized water, and fully dissolved by stirring and ultrasonication to obtain an aqueous phase solution. Then the aqueous phase solution was added to the organic phase solution, and ultrasonication was performed for 1 hour while keeping the temperature below 40°C to ensure that the aqueous phase solution was fully dispersed in the organic phase solution.

[0051] Then, argon inert gas was introduced into the part below the liquid level in the three-necked flask, and the gas was continuously ventilated for 40 minutes while bubbles continuously and evenly emerged to ensure that there was no oxygen inside the reactor and to ensure the smooth progress of the reaction. Then the bottle stopper was tightly sealed and stirred slowly for 24 hours at a water bath temperature of 40°C. Then 120mL of tetrahydrofuran (THF) was added to break the emulsion. After standing for 12 hours, the mixture was centrifuged at 4500rpm for 15 minutes, the lower precipitate was removed, and it was repeatedly washed with THF for 3-5 times. Finally, the lower precipitate was mixed with 60mL of 0.01moL / L phosphate buffer (PBS) to obtain a nanohydrogel particle dispersion.

[0052] 3) Preparation of metal electrode sheets loaded with nano-hydrogel particles

[0053] The platinum metal electrode sheet connected with active carboxyl groups (-COOH) obtained in step 1) is placed in the nano-hydrogel particle dispersion obtained in step 2) and immersed for 24 hours. The -COOH on the surface of the metal electrode sheet and the -NH2 on the surface of the hydrogel particles undergo a dehydration condensation reaction, and the nano-hydrogel particles are connected to the surface of the metal electrode sheet in the form of covalent bonds, completing the loading of the hydrogel particles.

[0054] Example 3: The surface of the platinum metal electrode sheet based on the hydrogel material provided in this example has an active carboxyl layer, and the active carboxyl layer is loaded with nano-hydrogel particles containing amino groups and long-chain carbon hydrophobic groups;

[0055] The preparation steps are:

[0056] 1) Pretreatment of metal electrode sheets

[0057] Cut out a 10mm×10mm platinum metal electrode sheet, and use anhydrous ethanol, acetone, 0.1mol / L dilute hydrochloric acid and deionized water to ultrasonically clean the metal electrode sheet to remove impurities such as metal oxides and oil stains on its surface. Then, soak it in 0.01mol / L 6-mercaptohexanoic acid alcohol solution for 2-4h at room temperature. After it is fully soaked for a sufficient time, rinse it with anhydrous ethanol, and transfer the rinsed electrode sheet to a mixed aqueous solution of 0.001mol / L 2-(N-morpholine)ethanesulfonic acid (MES), 0.002mol / L 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC·HCL) and 0.005mol / L N-hydroxysuccinimide (NHS) at room temperature, soak it for 24h and then take it out. Through the above pretreatment process, a platinum metal electrode sheet with active carboxyl (-COOH) connected on the surface is obtained.

[0058] 2) Preparation of Nanohydrogel Particles

[0059] Take 4.26g Tween 80, 4.92g Span 80 and 24mg initiator azobisisobutyl cyanide (AIBN) and dissolve them in 120mL n-hexane, put them into a 250mL three-necked flask and stir them evenly to obtain an organic phase solution for use. Then take 119.7mg [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfonic acid propyl)ammonium hydroxide (DMAPS), 541.7mg octadecyl methyl acrylate (N DMAPS :N 甲基乙烯酸十八烷基酯 =1:4), 84.2 mg of allylamine (AH), 13.8 mg of cross-linking agent N,N′-methylenebisacrylamide (MBA) were dissolved in 1.5 mL of deionized water, and fully dissolved by stirring and ultrasonication to obtain an aqueous phase solution. Then the aqueous phase solution was added to the organic phase solution, and ultrasonication was performed for 1 hour while keeping the temperature below 40°C to ensure that the aqueous phase solution was fully dispersed in the organic phase solution.

[0060] Then, argon inert gas was introduced into the part below the liquid level in the three-necked flask, and the gas was continuously ventilated for 40 minutes while bubbles continuously and evenly emerged to ensure that there was no oxygen inside the reactor and to ensure the smooth progress of the reaction. Then the bottle stopper was tightly sealed and stirred slowly for 24 hours at a water bath temperature of 40°C. Then 120mL of tetrahydrofuran (THF) was added to break the emulsion. After standing for 12 hours, the mixture was centrifuged at 4500rpm for 15 minutes, the lower precipitate was removed, and it was repeatedly washed with THF for 3-5 times. Finally, the lower precipitate was mixed with 60mL of 0.01moL / L phosphate buffer (PBS) to obtain a nanohydrogel particle dispersion.

[0061] 3) Preparation of metal electrode sheets loaded with nano-hydrogel particles

[0062] The platinum metal electrode sheet connected with active carboxyl groups (-COOH) obtained in step 1) is placed in the nano-hydrogel particle dispersion obtained in step 2) and immersed for 24 hours. The -COOH on the surface of the metal electrode sheet and the -NH2 on the surface of the hydrogel particles undergo a dehydration condensation reaction, and the nano-hydrogel particles are connected to the surface of the metal electrode sheet in the form of covalent bonds, completing the loading of the hydrogel particles.

[0063] Comparative Example 2: The difference from Example 1 is that steps 2) and 3) are not included.

[0064] Comparative Example 3: The difference from Example 1 is that step 1) is not performed.

[0065] The platinum metal electrode sheets based on hydrogel materials prepared in Examples 1 to 3 and the platinum metal electrode sheets prepared in Comparative Examples 1 to 3 were characterized and tested for performance. The results are shown in Figure 1-Figure 6 .

[0066] Figure 1 It can be seen that the distribution of nano-hydrogel particles on the surface of the metal electrode, Figure 2 Nanohydrogel particles under high magnification surface scanning electron microscopy.

[0067] Depend on Figure 3 It can be seen that the platinum metal electrode sheet based on the hydrogel material prepared in Example 1 is higher than the pure platinum electrode in Comparative Example 1 at 100 mA / cm 2 The overpotential can be reduced by 60 mV under the current density. It can be seen that the electrocatalytic reaction is more likely to occur after the nano-hydrogel particles are attached, and the electrocatalytic performance is significantly improved.

[0068] Depend on Figure 4 and Figure 5 It can be seen that the monomers of the nano hydrogel particles in Example 1 are replaced with hydrophobic monomers in proportion, wherein Example 2 is a monomer containing silicon oxygen group (-Si-O-), and Example 3 is a monomer containing long-chain carbon. The selection of Examples 2 and 3 proves that it is not only the hydrophilic monomers that have an effect on the water results, and the nano hydrogel particles containing hydrophobic groups can also change the water structure at the reaction interface, thereby affecting the electrochemical performance of the electrocatalytic reaction.

[0069] Depend on Figure 6It can be seen that Comparative Example 2 is an electrode sheet after being soaked in the alcohol solution of 0.01mol / L 6-mercaptohexanoic acid in step 1 for 2-4h, and Comparative Example 3 is an electrode sheet after being soaked in a mixed aqueous solution of 0.001mol / L 2-(N-morpholine)ethanesulfonic acid (MES), 0.002mol / L 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC·HCL) and 0.005mol / L N-hydroxysuccinimide (NHS) for 24h. Compared with Comparative Example 3, Comparative Example 2 does not have a significant change in electrochemical performance in Comparative Example 1, proving that the pretreatment step does not affect the electrochemical performance of the electrode sheet, and further, it can be concluded that the presence of nano-hydrogel particles affects the electrochemical performance.

Claims

1. A metal electrode sheet based on hydrogel material, characterized in that: The surface of the metal electrode sheet is provided with an active carboxyl layer, and the active carboxyl layer is loaded with nano hydrogel particles containing amino groups.

2. The metal electrode sheet according to claim 1, characterized in that: The metal electrode sheet is Pt, Ni, or Pd, and the particle size of the nano hydrogel particles is less than 500nm.

3. A method for preparing a metal electrode sheet based on a hydrogel material according to any one of claims 1 to 2, characterized in that: The following steps are involved: (1) Carboxylating the metal electrode sheet to obtain a metal electrode sheet having an active carboxyl layer; (2) preparing a dispersion of nano-hydrogel particles containing amino groups; (3) The metal electrode sheet with an active carboxyl group is immersed in a dispersion of nano-hydrogel particles containing amino groups, and the nano-hydrogel particles are connected to the surface of the metal electrode sheet by covalent bonds through a dehydration condensation reaction. The nano-hydrogel particle loading is completed to obtain a metal electrode sheet based on a hydrogel material.

4. The preparation method according to claim 3, characterized in that: In step (1), the carboxylation step is: (11) placing the metal electrode sheet after surface cleaning in an alcohol solution containing a thiol compound and fully immersing it, then taking it out and rinsing it; (12) The rinsed metal electrode sheet is placed in a mixed aqueous solution containing 2-(N-morpholine)ethanesulfonic acid, 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide and fully immersed, and then taken out after the end.

5. The preparation method according to claim 4, characterized in that: In step (11), the molar concentration of the thiol compound in the alcohol solution is 0.01-0.02 mol / L, and the immersion time is 2-4 h. In step (12), in the mixed aqueous solution, the molar concentration of 2-(N-morpholine)ethanesulfonic acid is 0.001-0.002 mol / L, the molar concentration of 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride is 0.002-0.003 mol / L, the molar concentration of N-hydroxysuccinimide is 0.005-0.006 mol / L, and the immersion time is 24 h-48 h.

6. The preparation method according to claim 3, characterized in that: In step (2), the preparation steps of the dispersion of the nano hydrogel particles containing amino groups are: (21) dissolving the active agent and the initiator in an organic solvent and mixing them to obtain an organic phase solution; (22) dissolving the polymer monomer, allylamine, and the cross-linking agent in water and mixing to obtain an aqueous solution; (23) The aqueous phase solution is added to the organic phase solution, ultrasonically dispersed, and deoxygenated after being fully dispersed. The solution is then stirred in a water bath, demulsified, allowed to stand, and centrifuged. The lower precipitate is removed, repeatedly washed, and mixed with a buffer solution to obtain a dispersion of nano-hydrogel particles containing amino groups.

7. The preparation method according to claim 6, characterized in that: In step (21), the amount ratio of the active agent, the initiator and the organic solvent is 9.18-10g:24mg:120-200mL, the active agent includes Tween 80 and Span 80, and the initiator is azobisisobutyl cyanide; in step (22), the amount ratio of the polymer monomer, allylamine, the crosslinking agent and water is 0.02-0.025mol:84.2mg:13.8mg:1.5-2mL; the polymer monomer is an olefinic monomer or a combination of an olefinic monomer and a functional monomer for enhancing hydrophobic properties; the crosslinking agent is N,N′-methylenebisacrylamide; in step (23), the parameters of the ultrasonic dispersion are: ultrasonication at below 40°C for 1-2h; the parameters of the water bath stirring are: stirring at 40-50°C for 24-28h; the reagent used for the demulsification treatment is tetrahydrofuran, and the buffer is 0.01-0.02moL / L phosphate buffer.

8. The preparation method according to claim 7, characterized in that: The polymer monomer is a combination of an olefinic monomer and a functional monomer for enhancing hydrophobicity, and the molar ratio of the olefinic monomer to the functional monomer for enhancing hydrophobicity is 1:3.5-4.

5.

9. The preparation method according to claim 3, characterized in that: In step (3), the conditions of the dehydration condensation reaction are: reacting at 40-50° C. for 24-30 hours.

10. Use of the metal electrode sheet based on the hydrogel material according to any one of claims 1 to 2 in the field of alkaline electrocatalytic hydrogen evolution.

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