Hydrogel patterned super-infiltration porous electrode and preparation method and application thereof
By constructing microgrooves on the surface of a porous conductive substrate and filling them with non-conductive hydrogel, and combining the conductive hydrogel as an electrolyte for the catalytic layer, the problem of bubble adhesion under high current density was solved, achieving efficient mass transfer and stable electrochemical performance, and extending electrode life.
Patent Information
- Application Number
- CN202511769290.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-28
- Publication Date
- 2026-02-10
AI Technical Summary
Existing technologies lack electrode structures that can effectively promote rapid bubble detachment under high current density conditions without relying on external energy consumption. This leads to bubble adhesion that obscures active sites, increases mass transfer resistance, and affects electrochemical performance and stability.
A hydrogel-patterned ultrawetting porous electrode is used. By constructing microgrooves on the surface of a porous conductive substrate and filling them with non-conductive hydrogel, a reverse transport channel for gas-liquid separation is formed. Combined with a quasi-solid electrolyte with conductive hydrogel as the catalyst layer, spontaneous desorption of bubbles and rapid transport of liquid reactants are achieved.
It significantly improves mass transfer efficiency, reduces polarization overpotential, avoids mechanical damage to the catalyst layer, extends electrode life, and simplifies system structure to reduce operating costs.
Smart Images
Figure CN121506970A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrochemical energy conversion technology, and in particular to a hydrogel patterned superwetting porous electrode, its preparation method, and its application. Background Technology
[0002] Against the backdrop of energy structure transformation driven by the "dual carbon" goal, direct liquid fuel cells (such as direct methanol fuel cells and direct formic acid fuel cells) and water electrolysis technology have attracted widespread attention as efficient and clean electrochemical energy conversion technologies. However, these two types of technologies face challenges in practical applications, especially under high current density conditions (above 100 mA / cm²). 2 Inevitably, a large amount of gaseous products (such as CO2, O2, H2, etc.) will be generated on the electrode surface. The attachment, growth, and detachment of bubbles on the electrode surface will significantly affect the electrochemical performance and long-term stability of the system. Specifically, the attachment of bubbles on the electrode surface will obscure active sites, increase mass transfer resistance, and lead to significant polarization overpotential and energy efficiency loss; the periodic growth and detachment of bubbles will also cause local current density and temperature fluctuations, resulting in unstable power output, and may even induce mechanical damage to the catalyst layer and peeling off of active materials, shortening the electrode's lifespan.
[0003] Currently, methods for controlling bubble behavior on the surface of gas evolution electrodes are mainly divided into two categories: active and passive. Active methods rely on external fields (such as fluid shear, electric fields, ultrasound, magnetic fields, etc.) to apply additional driving force to induce bubble detachment. However, these methods require external devices and energy consumption, increasing system complexity and operating costs. Passive methods focus on reducing bubble adhesion by constructing superhydrophobic or superhydrophilic surface structures to promote spontaneous bubble desorption. However, these methods still face challenges in terms of the stability, scalability, and fabrication process of functional surfaces, making it difficult to meet the needs of large-scale engineering applications.
[0004] Therefore, there is a lack of an electrode structure in the current technology that can effectively promote the rapid release of bubbles, does not rely on external energy consumption, and has good structural stability and process scalability. This has become a key technical bottleneck restricting the further development of direct liquid fuel cells and water electrolysis technology under high current density conditions. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a hydrogel patterned superwetting porous electrode, its preparation method, and its application.
[0006] To achieve the above objectives, the present invention provides a hydrogel patterned ultrawetting porous electrode, comprising: Porous conductive substrate; A microgroove structure is disposed on a surface of a porous conductive substrate, and the microgroove is filled with non-conductive hydrogel. A catalytic layer is disposed on the other surface of a porous conductive substrate. The catalytic layer contains a catalyst and a conductive hydrogel.
[0007] Preferably, the material of the non-conductive hydrogel is selected from polyvinyl alcohol or agar.
[0008] Preferably, the microgroove structure is formed by femtosecond laser etching, and the depth of the microgroove is 20%-80% of the thickness of the porous conductive substrate.
[0009] Preferably, the porous conductive substrate is selected from porous carbon paper or metal felt.
[0010] Preferably, the porous conductive substrate undergoes a hydrophilic treatment; when the porous conductive substrate is porous carbon paper, the hydrophilic treatment includes anodic oxidation or acid bath treatment; when the porous conductive substrate is metal felt, the hydrophilic treatment includes electrochemical oxidation-reduction treatment.
[0011] Preferably, the catalyst in the catalyst layer is selected from at least one of Pt-based catalysts, Pd-based catalysts, Ru-based catalysts, and Ir-based catalysts.
[0012] Preferably, the conductive hydrogel is a composite gel, which comprises a hydrogel matrix and conductive fillers dispersed in the hydrogel matrix.
[0013] Preferably, the hydrogel matrix is selected from polyvinyl alcohol or agar; the conductive filler is selected from at least one of carbon nanotubes, graphene, and carbon black.
[0014] The present invention also provides a method for preparing the aforementioned hydrogel patterned superwetting porous electrode, comprising the following steps: Hydrophilic treatment of porous conductive substrates; Microgrooves are formed on the surface of a porous conductive substrate by etching with a femtosecond laser; a non-conductive hydrogel solution is filled into the microgrooves and then freeze-dried to form a hydrogel pattern. A catalyst slurry containing conductive filler, a hydrogel matrix, and a catalyst is coated on the other surface of a porous conductive substrate and then freeze-dried to form a catalyst layer.
[0015] The present invention also provides the application of the aforementioned hydrogel patterned ultrawetting porous electrode in a direct liquid fuel cell or water electrolysis device.
[0016] The beneficial effects of this invention are as follows: 1. This invention provides a hydrogel-patterned superwetting porous electrode, comprising: a porous conductive substrate; a microgroove structure disposed on one surface of the porous conductive substrate, the microgroove being filled with non-conductive hydrogel; and a catalytic layer disposed on the other surface of the porous conductive substrate, the catalytic layer comprising a catalyst and conductive hydrogel. This invention, by constructing microgrooves on the surface of the porous conductive substrate and filling them with non-conductive hydrogel, forms a reverse gas-liquid separation transport channel with the surrounding conductive region: liquid-phase reactants can rapidly diffuse along the hydrogel or the porous conductive substrate to the catalytic layer, while gaseous products are reversely discharged through the porous conductive substrate, thereby effectively avoiding the obstruction of reactant transport by bubbles and significantly improving mass transfer efficiency. By introducing conductive hydrogel as a quasi-solid electrolyte in the catalytic layer, not only is a good electronic conduction path maintained, but the shielding of catalytic active sites by bubbles is also eliminated, significantly reducing polarization overpotential. Simultaneously, the hydrogel can buffer the dragging effect on catalyst particles when bubbles detach, avoiding mechanical damage to the catalytic layer and peeling off of active materials caused by the periodic growth and detachment of bubbles, thereby extending electrode life.
[0017] 2. Introducing acid-treated conductive fillers into conductive hydrogels further enhances electronic conductivity and reduces ohmic polarization loss.
[0018] 3. The hydrogel material used is widely available and inexpensive, with a simple preparation process that requires no complex equipment. It is suitable for various catalyst systems and reaction types, and has good process scalability and application compatibility.
[0019] 4. The composition, thickness, water content and pore structure of the hydrogel coating can be flexibly adjusted according to actual reaction requirements, adapting to different electrolyte systems and reaction conditions, and exhibiting excellent engineering adaptability.
[0020] 5. This invention enables spontaneous desorption of bubbles without relying on external field auxiliary equipment, which helps to simplify the system structure, reduce operating costs, and improve the overall energy efficiency and reliability of the battery system. Attached Figure Description
[0021] Figure 1 This is a front view of the hydrogel patterned ultrawetting porous electrode of the present invention; Figure 1 In the diagram, 1 represents a microgroove filled with non-conductive hydrogel, 2 represents a porous conductive substrate, and 3 represents a catalytic layer. Figure 2 This is a top view of the hydrogel patterned ultrawetting porous electrode of the present invention; Figure 2 In the image, 1 represents a microgroove filled with non-conductive hydrogel, and 2 represents a porous conductive substrate. Figure 3 This is a side view of the hydrogel patterned ultrawetting porous electrode of the present invention; Figure 3 In the diagram, 2 represents a porous conductive substrate, and 3 represents a catalyst layer; Figure 4 This is a graph showing the catalytic oxidation performance of formic acid by different electrodes in Experiment Example 1 of this invention. Detailed Implementation
[0022] This invention provides a hydrogel-patterned ultrawetting porous electrode, comprising: Porous conductive substrate; A microgroove structure is disposed on a surface of a porous conductive substrate, and the microgroove is filled with non-conductive hydrogel. A catalytic layer is disposed on the other surface of a porous conductive substrate. The catalytic layer contains a catalyst and a conductive hydrogel.
[0023] Superwetting means superhydrophilic.
[0024] A front view of the hydrogel-patterned superwetting porous electrode in this invention, as shown below. Figure 1 As shown; Figure 1 In the diagram, 1 represents a microgroove filled with non-conductive hydrogel, 2 represents a porous conductive substrate, and 3 represents a catalyst layer.
[0025] A top view of the hydrogel-patterned superwetting porous electrode in this invention, as shown below. Figure 2 As shown; Figure 2 In the diagram, 1 represents a microgroove filled with non-conductive hydrogel, and 2 represents a porous conductive substrate.
[0026] A side view of the hydrogel-patterned superwetting porous electrode in this invention, as shown below. Figure 3 As shown; Figure 3 In the diagram, 2 represents the porous conductive substrate, 3 represents the catalyst layer, and the dashed line indicates the depth of the microgroove.
[0027] In this invention, the material of the non-conductive hydrogel is selected from polyvinyl alcohol or agar.
[0028] In this invention, the microgroove structure is formed by femtosecond laser etching, and the depth of the microgroove is 20%-80% of the thickness of the porous conductive substrate.
[0029] In this invention, the porous conductive substrate is selected from porous carbon paper or metal felt; the metal felt is selected from titanium felt.
[0030] In this invention, the porous conductive substrate undergoes a hydrophilic treatment; when the porous conductive substrate is porous carbon paper, the hydrophilic treatment includes anodic oxidation or acid bath treatment; when the porous conductive substrate is metal felt, the hydrophilic treatment includes electrochemical oxidation-reduction treatment.
[0031] In this invention, the catalyst in the catalyst layer is selected from at least one of Pt-based catalysts, Pd-based catalysts, Ru-based catalysts, and Ir-based catalysts.
[0032] In this invention, a Pt-based catalyst or a Pd-based catalyst is used for the oxidation reaction of small molecule liquid fuels; a Pt-based catalyst is used for the hydrogen evolution reaction; and a Ru-based catalyst or an Ir-based catalyst is used for the oxygen evolution reaction.
[0033] In this invention, the conductive hydrogel is a composite gel, which comprises a hydrogel matrix and conductive fillers dispersed in the hydrogel matrix.
[0034] In this invention, the hydrogel matrix is selected from polyvinyl alcohol or agar; the conductive filler is selected from at least one of carbon nanotubes, graphene, and carbon black.
[0035] In this invention, the conductive filler is treated with an acid bath to increase the oxygen functional groups on its surface.
[0036] The present invention also provides a method for preparing the aforementioned hydrogel patterned superwetting porous electrode, comprising the following steps: Hydrophilic treatment of porous conductive substrates; Microgrooves are formed on the surface of a porous conductive substrate by etching with a femtosecond laser; a non-conductive hydrogel solution is filled into the microgrooves and then freeze-dried to form a hydrogel pattern. A catalyst slurry containing conductive filler, a hydrogel matrix, and a catalyst is coated on the other surface of a porous conductive substrate and then freeze-dried to form a catalyst layer.
[0037] In this invention, the process of filling a non-conductive hydrogel solution into a microgroove and then freeze-drying it to form a hydrogel pattern includes: mixing a non-conductive hydrogel (polyvinyl alcohol or agar) with water and stirring until completely dissolved to obtain a non-conductive hydrogel solution; slowly adding it dropwise into the microgroove until it is completely filled; and then performing freeze-drying treatment. After complete freeze-drying, a non-conductive hydrogel pattern can be formed in the microgroove.
[0038] In this invention, the process of coating a catalyst slurry on another surface of a porous conductive substrate and then freeze-drying it to form a catalyst layer includes: mixing a catalyst, a hydrogel matrix (polyvinyl alcohol or agar), a conductive filler, and ethanol to obtain a catalyst slurry; then uniformly coating the catalyst slurry on the back side of a porous conductive substrate that forms a non-conductive hydrogel pattern, and freeze-drying it. After complete freeze-drying, the substrate is removed until the temperature returns to room temperature, and the freeze-drying-restoration process is repeated multiple times to form a structurally stable conductive hydrogel composite catalyst layer.
[0039] In this invention, before the hydrogel patterned ultrawetting porous electrode is put into use, it needs to be immersed in the electrolyte until the hydrogel is fully swollen to complete the electrode activation preparation.
[0040] The present invention also provides the application of the aforementioned hydrogel patterned ultrawetting porous electrode in a direct liquid fuel cell or water electrolysis device.
[0041] In this invention, during the operation of the hydrogel-patterned ultrawetted porous electrode, the liquid-phase reactants first diffuse from the bulk solution and are transported to the interface between the catalyst layer and the porous conductive substrate via the non-conductive hydrogel (the non-conductive hydrogel filling the micro-groove) or the porous conductive substrate. Subsequently, they further diffuse to the active sites of the catalyst through the conductive hydrogel (the conductive hydrogel in the catalyst layer), where electrochemical oxidation or reduction reactions occur. During the reaction, electrons are conducted through the conductive hydrogel (the conductive hydrogel in the catalyst layer) to the porous conductive substrate and eventually flow to the external circuit. The generated gaseous products precipitate, nucleate, and gradually grow into bubbles on the surface of the conductive hydrogel (the conductive hydrogel in the catalyst layer). These bubbles are transported in the reverse direction along the porous conductive substrate to the interface between the electrode and the solution, where they continue to grow and coalesce, eventually detaching from the electrode surface.
[0042] The key advantages of the hydrogel-patterned superwetting porous electrode of this invention are as follows: Firstly, the hydrogel located within the catalyst layer not only functions as an electronic conductor but also significantly weakens the "shielding effect" of adhered bubbles on the catalyst layer, thereby maintaining continuous transport channels for liquid-phase reactants and effectively reducing polarization losses. Simultaneously, the dragging effect on catalyst particles during bubble detachment is avoided, improving the structural stability and lifespan of the catalyst layer. Secondly, the hydrogel filled within the microgrooves possesses superhydrophilic / superhydrophobic properties, ensuring not only efficient liquid-phase mass transfer but also achieving an "insulating" effect on bubbles. Combined with the gas-liquid forward / reverse transport channels constructed by adjacent porous conductive substrates, this structure allows liquid-phase reactants and gas-phase products to "travel independently," further improving mass transfer efficiency and significantly enhancing the overall performance of the electrode.
[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The features mentioned above or the features mentioned in the specific examples of this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.
[0044] Example 1 This embodiment provides a method for preparing a hydrogel-patterned ultrawetting porous electrode, comprising the following steps: Take a porous carbon paper with a thickness of 300 micrometers (manufacturer: Shanghai Hesen Electric Co., Ltd., model: HCP030N) and soak it in an acid solution (the acid solution is obtained by mixing a 98% sulfuric acid solution and a 65% nitric acid solution at a volume ratio of 3:1) for 12 hours (at 25°C). After soaking, wash it with water until it is neutral and dry it for later use.
[0045] A femtosecond laser processing system (wavelength set at 515nm, pulse width at 100ps) was used to etch a parallel microgroove array with a width of 1mm and a depth equal to 80% of the thickness of the porous carbon paper on the surface after hydrophilic treatment, with the microgroove spacing controlled at 1mm. 10g of polyvinyl alcohol (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., model: 1799) was mixed with 100mL of water and stirred at 25℃ until completely dissolved to obtain a non-conductive hydrogel solution. This solution was slowly added dropwise into the microgrooves until completely filled, followed by freeze-drying (at -25℃). After complete freeze-drying, a non-conductive hydrogel pattern was formed.
[0046] Carbon nanotubes (manufacturer: Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., model: XFM01) were immersed in an acid solution (prepared by mixing 98% sulfuric acid solution and 65% nitric acid solution at a volume ratio of 3:1) at 25°C for 12 hours for acid bath treatment. After immersion, they were washed with water until neutral and dried to obtain acid-treated carbon nanotubes. Pd-based catalyst (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., product number: 230218919565653, specification: 5g), polyvinyl alcohol (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., model: 1799), acid-treated carbon nanotubes, and ethanol were weighed in a mass ratio of 30:10:5:55 and thoroughly mixed to obtain a catalyst slurry. The catalyst slurry was then uniformly coated onto the back of porous carbon paper forming a non-conductive hydrogel pattern (coating amount: 1.0 mg / cm²). 2 The electrode is subjected to freeze-drying treatment (at a temperature of -25°C). After complete freeze-drying, it is taken out until the temperature returns to room temperature. The freeze-drying-recovery process is repeated three times to form a catalytic layer and obtain a hydrogel patterned superwetting porous electrode.
[0047] The hydrogel-patterned superwetting porous electrode was immersed in a 0.5 mol / L sulfuric acid solution (at 25°C) for 30 min to allow the hydrogel to fully swell before use.
[0048] Example 2 This embodiment provides a method for preparing a hydrogel-patterned ultrawetting porous electrode, comprising the following steps: Take a porous titanium felt with a thickness of 250 micrometers (manufacturer: BEKAERT), and clean it with acetone, ethanol and water in sequence for 30 minutes. Then, place the cleaned titanium felt in a 37% hydrochloric acid solution and perform surface hydrophilization treatment at 45°C for 20 minutes. At the same time, stir the solution to ensure that the material surface is uniformly formed with superhydrophilicity. After washing with water, dry it for later use.
[0049] A femtosecond laser processing system (wavelength set at 515nm, pulse width at 200ps) was used to etch a parallel microgroove array with a width of 1mm and a depth equal to 80% of the porous titanium felt thickness on the surface of a hydrophilically treated porous titanium felt, with the microgroove spacing controlled at 1mm. 10g of polyvinyl alcohol (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., model: 1799) was mixed with 100mL of water and stirred at 25℃ until completely dissolved to obtain a non-conductive hydrogel solution. This solution was slowly added dropwise into the microgrooves until completely filled, followed by freeze-drying (at -20℃). After complete freeze-drying, a non-conductive hydrogel pattern was formed.
[0050] Graphene (manufacturer: Jiangsu Xianfeng Nanomaterials Technology Co., Ltd., model: XFDZ01) was immersed in an acid solution (prepared by mixing 98% sulfuric acid solution and 65% nitric acid solution at a volume ratio of 3:1) at 25°C for 12 hours for acid bath treatment. After immersion, it was washed with water until neutral and dried to obtain acid-treated graphene. Ir-based catalyst (manufacturer: Shanghai Hesen Electric Co., Ltd., model: HIR100), agar (manufacturer: Biosharp, model: BS195-500g), acid-treated graphene, and ethanol were weighed in a mass ratio of 30:10:5:55 and thoroughly mixed to obtain a catalyst slurry. The catalyst slurry was then uniformly coated on the back of a porous titanium felt forming a non-conductive hydrogel pattern (coating amount: 1.0 mg / cm²). 2 The electrode is subjected to freeze-drying treatment (at a temperature of -20°C). After complete freeze-drying, it is taken out until the temperature returns to room temperature. The freeze-drying-recovery process is repeated 3 times to form a catalytic layer and obtain a hydrogel patterned superwetting porous electrode.
[0051] The hydrogel-patterned superwetting porous electrode was immersed in a 0.5 mol / L sulfuric acid solution (at 25°C) for 30 min to allow the hydrogel to fully swell before use.
[0052] Experimental Example 1 The hydrogel patterned superwetting porous electrode from Example 1 and the conventional porous electrode were tested for their formic acid catalytic oxidation performance. The electrolyte used in the test was an acid solution, which included formic acid, sulfuric acid, and water. The concentration of formic acid in the acid solution was 0.5 mol / L, and the concentration of sulfuric acid was 0.5 mol / L. The potential scan range was -0.2 V to 0.8 V (relative to the Ag / AgCl reference electrode), and the scan rate was 10 mV / s. The preparation process of the conventional porous electrode was as follows: a porous carbon paper with a thickness of 300 micrometers (manufacturer: Shanghai Hesen Electric Co., Ltd., model: HCP030N) was taken, ultrasonically cleaned in ethanol for 30 min, rinsed with deionized water after cleaning, and finally dried in an oven at 60°C for later use. A catalyst slurry was prepared by thoroughly mixing 30 mg of palladium black (manufacturer: Shanghai Aladdin Biochemical Technology Co., Ltd., product number: P282903-1g), 0.5 mL of deionized water, 2.0 mL of ethanol, and 106 mg of Nafion solution (manufacturer: Shanghai Hesen Electric Co., Ltd., model: D520). An appropriate amount of the catalyst slurry was placed in a spray gun and evenly sprayed onto the surface of a prepared porous carbon paper under a nitrogen atmosphere. After drying with cold air, the slurry was sprayed again, repeating this process multiple times until the final spraying amount of catalyst slurry was controlled to be 1.0 mg / cm³. 2 A traditional porous electrode was obtained. Performance curves of different electrodes for the catalytic oxidation of formic acid were obtained, as shown in the figure. Figure 4 As shown. From Figure 4 The results show that the peak current density of the hydrogel-patterned superwetted porous electrode in the formic acid catalytic oxidation reaction is increased by 86.5% compared with that of the conventional porous electrode. Meanwhile, it can be observed that the performance curve of the conventional porous electrode shows significant fluctuations in the high current density region, which is attributed to the mass transfer instability caused by the growth and detachment of bubbles on the electrode surface; in contrast, the performance curve of the hydrogel-patterned superwetted porous electrode remains stable without significant fluctuations.
[0053] Therefore, this invention employs a hydrogel-patterned superwetting porous electrode, as described above. By constructing microgrooves on the surface of a porous conductive substrate and filling them with non-conductive hydrogel, a reverse transport channel for gas-liquid separation is formed with the surrounding conductive area. Liquid-phase reactants can rapidly diffuse along the hydrogel or porous conductive substrate to the catalyst layer, while gaseous products are reversely discharged through the porous conductive substrate. This effectively avoids the obstruction of reactant transport by bubbles and significantly improves mass transfer efficiency. By introducing conductive hydrogel as a quasi-solid electrolyte into the catalyst layer, not only is a good electronic conduction path maintained, but the shielding of catalytic active sites by bubbles is also eliminated, significantly reducing polarization overpotential. Simultaneously, the hydrogel can buffer the dragging effect on catalyst particles during bubble detachment, avoiding mechanical damage to the catalyst layer and peeling off of active materials caused by the periodic growth and detachment of bubbles, thereby extending electrode life.
[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A hydrogel-patterned ultrawetting porous electrode, characterized in that, include: Porous conductive substrate; A microgroove structure is disposed on a surface of a porous conductive substrate, and the microgroove is filled with non-conductive hydrogel. A catalytic layer is disposed on the other surface of a porous conductive substrate. The catalytic layer contains a catalyst and a conductive hydrogel.
2. The hydrogel patterned ultrawetting porous electrode according to claim 1, characterized in that, The material of the non-conductive hydrogel is selected from polyvinyl alcohol or agar.
3. The hydrogel patterned ultrawetting porous electrode according to claim 1, characterized in that, The microgroove structure is formed by femtosecond laser etching, and the depth of the microgroove is 20%-80% of the thickness of the porous conductive substrate.
4. The hydrogel patterned ultrawetting porous electrode according to claim 1, characterized in that, The porous conductive substrate is selected from porous carbon paper or metal felt.
5. The hydrogel patterned ultrawetting porous electrode according to claim 4, characterized in that, The porous conductive substrate undergoes a hydrophilic treatment; when the porous conductive substrate is porous carbon paper, the hydrophilic treatment includes anodic oxidation or acid bath treatment; when the porous conductive substrate is metal felt, the hydrophilic treatment includes electrochemical oxidation-reduction treatment.
6. The hydrogel patterned ultrawetting porous electrode according to claim 1, characterized in that, The catalyst in the catalyst layer is selected from at least one of Pt-based catalysts, Pd-based catalysts, Ru-based catalysts, and Ir-based catalysts.
7. The hydrogel patterned ultrawetting porous electrode according to claim 1, characterized in that, The conductive hydrogel is a composite gel, which includes a hydrogel matrix and conductive fillers dispersed in the hydrogel matrix.
8. The hydrogel patterned ultrawetting porous electrode according to claim 7, characterized in that, The hydrogel matrix is selected from polyvinyl alcohol or agar; the conductive filler is selected from at least one of carbon nanotubes, graphene, and carbon black.
9. The method for preparing the hydrogel patterned ultrawetting porous electrode according to any one of claims 1-8, characterized in that, Includes the following steps: Hydrophilic treatment of porous conductive substrates; Microgrooves are formed on the surface of a porous conductive substrate by etching with a femtosecond laser. A non-conductive hydrogel solution is filled into a microgroove and then freeze-dried to form a hydrogel pattern. A catalyst slurry containing conductive filler, a hydrogel matrix, and a catalyst is coated on the other surface of a porous conductive substrate and then freeze-dried to form a catalyst layer.
10. The application of the hydrogel patterned ultrawetting porous electrode according to any one of claims 1-8 in a direct liquid fuel cell or water electrolysis device.