Preparation method and application of low-energy-consumption and high-selectivity foam metal electrode material

Abstract

The invention specifically discloses a preparation method and application of a low-energy-consumption and high-selectivity foam metal electrode material, and the method comprises the steps: bonding selected sponges with different specifications through a sponge binder mixed with metal powder, and carrying out the conductive treatment of the bonded sponges; electroplating the sponge subjected to the conductive treatment on the basis of a pre-prepared electroplating solution; sintering the electroplated semi-finished product in an oxygen atmosphere, and performing metal reduction in a hydrogen atmosphere; and infiltrating the sintered semi-finished product in dilute nitric acid in an inert gas atmosphere, so that hydrophilic groups generated by the reaction are grafted on the surface of the sintered semi-finished product. The aperture of the electrode material is subjected to gradient design, so that bubbles are easy to separate, the overall energy consumption is reduced, the active sites of the foam metal are increased, and the activity of the electrode material is improved; and hydrophilic groups are grafted on the surface of the electrode material, so that the electrode material is changed from hydrophobicity to hydrophilicity, and the electrode material has high selectivity.

Description

Technical Field

[0001] This application belongs to the field of electrolytic water catalytic materials technology, and in particular relates to a method for preparing and applying a low-energy-consumption and high-selectivity foam metal electrode material. Background Technology

[0002] Hydrogen production via water electrolysis is a process that generates hydrogen and oxygen by electrolyzing water molecules, and is considered an important method for producing green hydrogen. The basic principle of this technology is to pass a direct current through an electrolyzer, causing water molecules to undergo an electrochemical reaction at the electrodes, thus decomposing into hydrogen and oxygen. Currently, most OER electrode materials are woven nickel mesh rather than foamed metal. This is mainly because the surface of foamed metal materials is usually hydrophobic, meaning that water droplets form a large contact angle on its surface, which is not conducive to the hydrogen production reaction via water electrolysis. Furthermore, the surface of foamed metal is often occupied by oxygen bubbles. Oxygen bubbles adhere to the electrodes, reducing the active surface area of ​​the electrode and increasing the resistance in that area, thus leading to a decrease in electrochemical performance and an increase in overall energy consumption.

[0003] Therefore, researching a foam metal material that can promote bubble detachment from the electrode, reduce the residence time of bubbles on the electrode, and improve electrode selectivity is a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a method for preparing low-energy-consumption and highly selective foamed metal electrode materials, the method comprising:

[0005] S100, bonding and conductive treatment: The selected sponges of different specifications are bonded together by a sponge adhesive mixed with metal powder, and the bonded sponges are then treated to make a layer of conductive metal spread on the surface of the sponge filaments.

[0006] S200, Electroplating: Electroplating the conductive sponge with a pre-prepared electroplating solution and cleaning the electroplated semi-finished product.

[0007] S300, Sintering: The electroplated semi-finished product is fully combusted in an oxygen atmosphere to remove the sponge skeleton, and then the metal is reduced in a hydrogen atmosphere to convert the oxidized metal into the reduced pure metal.

[0008] S400 Activation: Under an inert gas atmosphere, the sintered semi-finished product is immersed in dilute nitric acid to react, and the hydrophilic groups generated by the reaction are grafted onto the surface of the sintered semi-finished product to obtain a low-energy-consumption and high-selectivity foam metal electrode material.

[0009] In some embodiments, the different specifications of sponges in step S100 refer to sponges with different pore sizes.

[0010] In some embodiments, step S100 specifically involves: first, selecting sponges with decreasing or increasing pore sizes; then, uniformly applying a sponge adhesive mixed with metal powder to the bonding surface of the selected sponges to ensure full adhesion; and finally, uniformly coating the surface of the bonded sponge filaments with a layer of conductive metal using magnetron sponge technology or chemical plating technology.

[0011] In some embodiments, in step S200, the pre-prepared electroplating solution has a pH value of 5-9, and the electroplating solution is one of nickel electroplating solution, molybdenum electroplating solution, or cobalt electroplating solution.

[0012] In some embodiments, step S200, specifically electroplating the conductive sponge based on a pre-configured electroplating solution, involves setting two anodes on both sides of the cathode and setting different current densities on both sides of the cathode based on the pre-configured electroplating solution and the sponge, so as to plate a metal coating of corresponding thickness at the sponge bonding point. The electroplating time is 1-30 min, the current density is 1-80 ASD, and the electroplating solution temperature is 55-65℃.

[0013] In some embodiments, in step S200, cleaning the electroplated semi-finished product after electroplating specifically involves rinsing the electroplated semi-finished product with pure water 2-4 times.

[0014] In some embodiments, in step S300, the temperature for complete combustion in an oxygen atmosphere is 300-700°C, and the combustion time is 1-10 minutes.

[0015] In some embodiments, in step S300, a three-stage metal reduction is performed under a hydrogen atmosphere, wherein the first stage reduction temperature is 300-900℃ and the reduction time is 1-3 min; the second stage reduction temperature is 200-600℃ and the reduction time is 2-9 min; and the third stage reduction temperature is 100-300℃ and the reduction time is 1-5 min.

[0016] In some embodiments, in step S400, the inert gas is at least one of nitrogen, helium, and argon.

[0017] This application also provides an application of a low-energy-consumption and high-selectivity foam metal electrode material, in which the low-energy-consumption and high-selectivity foam metal electrode material prepared by the above-described preparation method is applied to a water electrolysis hydrogen production electrode, thereby obtaining a low-energy-consumption and high-selectivity water electrolysis hydrogen production electrode.

[0018] Compared with existing technologies, this application provides a method for preparing low-energy-consumption and high-selectivity foam metal electrode materials and their applications. This method binds sponges with different pore sizes together to form an electrode material with an increasing pore size gradient. This makes it easier for bubbles to detach from the electrode material structurally, thereby reducing the residence time of bubbles on the electrode material and lowering overall energy consumption. By increasing the active sites of the foam metal, the activity of the electrode material is improved. Furthermore, this method utilizes dilute nitric acid to react with the sintered semi-finished product to generate hydrophilic groups grafted onto the sintered semi-finished product. The introduction of these hydrophilic groups reduces the contact angle of the electrode material surface, thus changing the surface of the prepared electrode material from hydrophobic to hydrophilic, thereby greatly improving the selectivity of the electrode material. Therefore, the foam metal electrode material prepared by the method provided in this application has the characteristics of low energy consumption and high selectivity. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a flowchart of the method for preparing a low-energy-consumption and highly selective foamed metal electrode material provided in this application.

[0021] Figure 2 This shows a scanning electron microscope (SEM) image of the foamed metal electrode material prepared in Example 3 of this application at 50x magnification.

[0022] Figure 3 The image shown is a scanning electron microscope (SEM) image of the foamed metal electrode material prepared in Example 3 of this application at 100x magnification.

[0023] Figure 4 The image shown is a scanning electron microscope (SEM) image of the foamed metal electrode material prepared in Example 3 of this application at 1000x magnification.

[0024] Figure 5 The graph shows the oxygen evolution reaction performance test results of the foam metal electrode material prepared in Example 3 of this application and the commercially available electrode material. Detailed Implementation

[0025] The "range" disclosed in this application is defined by a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, which define the boundaries of a particular range. Ranges defined in this way can include or exclude endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a specific parameter, it is expected that ranges of 60-110 and 80-120 are also included. Furthermore, if minimum range values ​​of 1 and 2 are listed, and if maximum range values ​​of 3, 4, and 5 are listed, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise stated, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this article; "0-5" is simply a shortened representation of these numerical combinations. Furthermore, when a parameter is stated as an integer ≥2, it is equivalent to disclosing that the parameter is, for example, an integer such as 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0026] Unless otherwise specified, the terms "comprising" and "including" as used in this application can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0027] Unless otherwise specified, the term "or" is inclusive in this application. For example, the phrase "A or B" means "A, B, or both A and B". More specifically, the condition "A or B" is satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).

[0028] like Figure 1 As shown in the embodiments of this application, a method for preparing a low-energy-consumption and highly selective foamed metal electrode material is provided, the method comprising:

[0029] S100, bonding and conductive treatment: The selected sponges of different specifications are bonded together by a sponge adhesive mixed with metal powder, and the bonded sponges are then treated to make a layer of conductive metal spread on the surface of the sponge filaments.

[0030] In this step, "different specifications of sponge" refers to sponges with different pore sizes. Specifically, first, sponges with pore sizes decreasing or increasing sequentially are selected; then, a sponge adhesive mixed with metal powder is evenly applied to the bonding surface of the selected sponges to ensure full adhesion, thus obtaining a sponge composite with gradient pore sizes; finally, a layer of conductive metal is evenly deposited on the surface of the bonded sponge filaments using magnetron sponge technology or chemical plating technology.

[0031] It should be noted that metal powder must be added to the adhesive during the bonding process of sponges of different specifications. Since metal powder is conductive, this can prevent the non-conductive bonding joint between sponges of different specifications from detaching from the electroplated sponge during the subsequent sintering process. The metal powder needs to have a uniform particle size, which can be in the micrometer or nanometer range.

[0032] S200, Electroplating: Electroplating is performed on the conductive sponge based on the pre-prepared electroplating solution, and the electroplated semi-finished product is cleaned. In order to avoid the risk of thin coating at the sponge bonding area, different coating thicknesses need to be plated at the sponge bonding area according to different PPI sponges. Therefore, during the electroplating process, two anodes need to be set on both sides of the cathode, and different current densities are set on both sides of the cathode according to the pre-prepared electroplating solution and the type of sponge. In this way, different coating thicknesses can be plated at the sponge bonding area.

[0033] In this step, the pre-prepared electroplating solution has a pH value of 5-6. The pH value of the pre-prepared electroplating solution is adjusted by boric acid, and the pH value is preferably 5.5. The electroplating solution is one of nickel electroplating solution, molybdenum electroplating solution or cobalt electroplating solution.

[0034] In this embodiment, the pre-prepared electroplating solution is a nickel electroplating solution, and the composition and ratio of the nickel electroplating solution include:

[0035]

[0036] Among them, nickel sulfate hexahydrate and nickel chloride hexahydrate provide nickel ions; nickel chloride hexahydrate and sodium chloride improve the conductivity of the plating solution, thereby promoting anodic dissolution; sodium dodecyl sulfate can improve the wettability of the plating solution on the plated product, thereby improving the plating solution's depth capability (also known as coverage capability, which refers to the ability of the plating solution to deposit a metal coating in the recesses or deep holes of the workpiece during the electroplating process).

[0037] In this step, since the pore size of the sponge after the conductivity treatment is inconsistent, its conductivity will also vary. In order to ensure the integrity of the coating of the sponge after conductivity treatment, it is necessary to improve the depth capability of the plating solution. Therefore, on the one hand, sodium dodecyl sulfate is added to the plating solution, and on the other hand, two anodes are set on both sides of the cathode, and the current density on both sides of the cathode is set to different current densities. This can effectively improve the integrity of the coating and avoid the phenomenon of local non-deposited metal in the sponge after conductivity treatment. The electroplating time is 1-30 min, for example, the electroplating time can be 1 min, 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc.; the current density is 1-80 ASD, for example, the current density can be 1 ASD, 10 ASD, 20 ASD, 30 ASD, 40 ASD, 50 ASD, 60 ASD, 70 ASD, 80 ASD, etc.; and the electroplating solution temperature is 55-65℃, for example, the electroplating solution temperature can be 55℃, 56℃, 57℃, 58℃, 59℃, 60℃, 61℃, 62℃, 63℃, 64℃, 65℃, etc.

[0038] In this step, after the conductive sponge is electroplated, the electroplated semi-finished product is rinsed with pure water to remove residual electroplating solution from the surface. The rinsing is performed 2-4 times, for example, 2, 3 or 4 times.

[0039] S300, Sintering: The electroplated semi-finished product is fully burned in an oxygen atmosphere to remove the sponge skeleton, and then the metal is reduced in a hydrogen atmosphere to convert the oxidized nickel into the reduced pure nickel.

[0040] In this step, the electroplated semi-finished product is fully burned in an oxygen atmosphere, which removes the sponge skeleton in the electroplated semi-finished product. The burning temperature is 300-700℃, for example, the burning temperature can be 300℃, 350℃, 400℃, 450℃, 500℃, 600℃, 700℃, etc., and the burning time is 1-10min, for example, the burning time can be 1min, 2min, 3min, 4min, 5min, 6min, 7min, 8min, 9min, 10min, etc.

[0041] In this step, the fully combusted electroplated semi-finished product undergoes a three-stage metal reduction process under a hydrogen atmosphere, thereby converting the oxidized metal into a reduced pure metal. Specifically:

[0042] The first reduction temperature is 300-900℃. For example, the first reduction temperature can be 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, 800℃, 850℃, 900℃, etc., and the reduction time is 1-3 minutes. For example, the reduction time can be 1 minute, 2 minutes, 3 minutes, etc.

[0043] The second-stage reduction temperature is 200-600℃. For example, the second-stage reduction temperature can be 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, etc.; the reduction time is 2-9 minutes. For example, the reduction time can be 2 minutes, 3 minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, etc.

[0044] The reduction temperature for the third stage is 100-300℃. For example, the reduction temperature for the third stage can be 100℃, 120℃, 140℃, 160℃, 180℃, 200℃, 220℃, 240℃, 260℃, 280℃, 300℃, etc., and the reduction time is 1-5 minutes. For example, the reduction time can be 1 minute, 2 minutes, 3 minutes, 4 minutes, 5 minutes, etc.

[0045] S400 Activation: Under an inert gas atmosphere, the sintered semi-finished product is immersed in dilute nitric acid to react, and the hydrophilic groups generated by the reaction are grafted onto the surface of the sintered semi-finished product to obtain a low-energy-consumption and high-selectivity foam metal electrode material.

[0046] In this step, the inert gas used in this embodiment is argon.

[0047] In this step, the sintered semi-finished product is first immersed in dilute nitric acid for 1-60 seconds. For example, the immersion time can be 1 second, 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds, 60 seconds, etc. At this time, the dilute nitric acid can remove oxides and impurities on the surface of the sintered semi-finished product. Then, through plasma technology, under an argon atmosphere, the surface of the foam metal is struck by argon ions, which generates and induces hydrophilic groups and makes the hydrophilic groups contact the active sites. In this way, the hydrophilic groups are grafted onto the active sites of the foam metal. The introduction of these hydrophilic groups reduces the contact angle of the foam metal surface, thereby changing the foam metal surface from hydrophobic to hydrophilic, making the foam metal more selective.

[0048] Dilute nitric acid reacts with the metal atoms on the surface of the sintered semi-finished foamed metal to generate metal oxides or hydroxides. These oxides or hydroxides are hydrophilic and can attract water molecules, thereby reducing the contact angle of water. The chemical reaction formula between dilute nitric acid and the surface of the sintered semi-finished foamed metal is as follows:

[0049] Ni + 4HNO3 → Ni(NO3)2 + 2NO2 + 2H2O

[0050] Ni(NO3)2 + 2H2O → Ni(OH)2 + 2HNO3

[0051] In the above embodiments, the method binds sponges with different pore sizes together to form an electrode material with an increasing pore size gradient. This makes it easier for bubbles to detach from the electrode material structurally, thereby reducing the residence time of bubbles on the electrode material and lowering overall energy consumption. Furthermore, by increasing the active sites of the foam metal, the activity of the electrode material is improved. Moreover, the method utilizes dilute nitric acid to react with the sintered semi-finished product to generate hydrophilic groups grafted onto the sintered semi-finished product. The introduction of these hydrophilic groups reduces the contact angle on the electrode material surface, thus changing the surface of the prepared electrode material from hydrophobic to hydrophilic, thereby greatly improving the selectivity of the electrode material. Therefore, the foam metal electrode material prepared by the method provided in this application has the characteristics of low energy consumption and high selectivity.

[0052] This application also provides an application of a low-energy-consumption and high-selectivity foam metal electrode material, in which the low-energy-consumption and high-selectivity foam metal electrode material prepared by the above-described preparation method is applied to a water electrolysis hydrogen production electrode, thereby obtaining a low-energy-consumption and high-selectivity water electrolysis hydrogen production electrode.

[0053] Based on the beneficial technical effects described in the above preparation method, the low-energy-consumption and high-selectivity foam metal electrode material prepared by this method is applied to the water electrolysis hydrogen production electrode. The resulting water electrolysis hydrogen production electrode has the same technical effects, namely, the prepared water electrolysis hydrogen production electrode can promote the detachment of bubbles from the electrode during the electrochemical reaction process, while reducing the residence time of bubbles on the electrode, thereby reducing the overall energy consumption and increasing the active sites. Moreover, based on the hydrophilic groups grafted on the surface of the foam metal, the selectivity of the electrode can be effectively improved.

[0054] To better illustrate the working principle and beneficial effects of the technical solution of this application, the following explanation will take the preparation of low-energy-consumption and high-selectivity electrode material products by the low-energy-consumption and high-selectivity foam metal preparation method provided in this application as an example.

[0055] Example 1

[0056] (1) Select sponges with decreasing or increasing pore sizes, apply sponge adhesive mixed with metal powder evenly to the selected sponges, and then use the sponge adhesive to bond the sponges with decreasing or increasing pore sizes into a whole. Then, based on magnetron sponge technology or chemical plating technology, lay a layer of conductive metal on the surface of the bonded sponge ribs.

[0057] (2) Electroplating the sponge obtained in step (1) based on the pre-configured nickel electroplating solution. The electroplating specifically includes: setting two anodes on both sides of the cathode and setting two different current densities on both sides of the cathode. The electroplating time is 30 min, and the two current densities are 1 ASD and 3 ASD respectively. The temperature of the pre-configured electroplating solution is 55℃. After the electroplating is completed, the electroplated semi-finished product is rinsed twice.

[0058] (3) The electroplated semi-finished product is fully combusted in an oxygen atmosphere at a temperature of 300°C for 10 minutes. Then, metal reduction is carried out in a hydrogen atmosphere to convert the oxidized nickel into reduced pure nickel. The first reduction stage is at a temperature of 300°C for 3 minutes, the second reduction stage is at a temperature of 200°C for 9 minutes, and the third reduction stage is at a temperature of 100°C for 5 minutes to obtain the sintered semi-finished product.

[0059] (4) Under an argon atmosphere, the sintered semi-finished product is immersed in dilute nitric acid to react. The dilute nitric acid reacts with the metal atoms on the surface of the sintered semi-finished foam metal and generates hydrophilic groups (metal oxides or hydroxides) grafted onto the active sites on the surface of the sintered semi-finished product, thus obtaining a low-energy-consumption and high-selectivity foam metal electrode material.

[0060] Example 2

[0061] (1) Select sponges with decreasing or increasing pore sizes, apply sponge adhesive mixed with metal powder evenly to the selected sponges, and then use the sponge adhesive to bond the sponges with decreasing or increasing pore sizes into a whole. Then, based on magnetron sponge technology or chemical plating technology, lay a layer of conductive metal on the surface of the bonded sponge ribs.

[0062] (2) Electroplating the sponge obtained in step (1) based on the pre-configured nickel electroplating solution. The electroplating specifically includes: setting two anodes on both sides of the cathode and setting two different current densities on both sides of the cathode. The electroplating time is 15 min, and the two current densities are 10 ASD and 30 ASD respectively. The temperature of the pre-configured electroplating solution is 60℃. After the electroplating is completed, the electroplated semi-finished product is rinsed. The rinsing number is 3 times.

[0063] (3) The electroplated semi-finished product is fully combusted in an oxygen atmosphere at a temperature of 500°C for 5 minutes. Then, metal reduction is carried out in a hydrogen atmosphere to convert the oxidized nickel into reduced pure nickel. The first reduction stage is at a temperature of 600°C for 2 minutes, the second reduction stage is at a temperature of 400°C for 5 minutes, and the third reduction stage is at a temperature of 200°C for 3 minutes to obtain the sintered semi-finished product.

[0064] (4) Under an argon atmosphere, the sintered semi-finished product is immersed in dilute nitric acid to react. The dilute nitric acid reacts with the metal atoms on the surface of the sintered semi-finished foam metal and generates hydrophilic groups (metal oxides or hydroxides) grafted onto the active sites on the surface of the sintered semi-finished product, thus obtaining a low-energy-consumption and high-selectivity foam metal electrode material.

[0065] Example 3

[0066] (1) Select sponges with decreasing or increasing pore sizes, apply sponge adhesive mixed with metal powder evenly to the selected sponges, and then use the sponge adhesive to bond the sponges with decreasing or increasing pore sizes into a whole. Then, based on magnetron sponge technology or chemical plating technology, lay a layer of conductive metal on the surface of the bonded sponge ribs.

[0067] (2) Electroplating the sponge obtained in step (1) based on the pre-configured nickel electroplating solution. The electroplating specifically includes: setting two anodes on both sides of the cathode and setting two different current densities on both sides of the cathode. The electroplating time is 1 min, and the two current densities are 60 ASD and 80 ASD respectively. The temperature of the pre-configured electroplating solution is 65°C. After the electroplating is completed, the electroplated semi-finished product is rinsed, and the rinsing is repeated 4 times.

[0068] (3) The electroplated semi-finished product is fully combusted in an oxygen atmosphere at a temperature of 700°C for 1 minute. Then, metal reduction is carried out in a hydrogen atmosphere to convert the oxidized nickel into reduced pure nickel. The first reduction temperature is 900°C and the reduction time is 1 minute; the second reduction temperature is 600°C and the reduction time is 2 minutes; the third reduction temperature is 300°C and the reduction time is 1 minute, resulting in a sintered semi-finished product.

[0069] (4) Under an argon atmosphere, the sintered semi-finished product is immersed in dilute nitric acid to react. The dilute nitric acid reacts with the metal atoms on the surface of the sintered semi-finished foam metal and generates hydrophilic groups (metal oxides or hydroxides) grafted onto the active sites on the surface of the sintered semi-finished product, thus obtaining a low-energy-consumption and high-selectivity foam metal electrode material.

[0070] The electrode material product prepared in Example 3 was analyzed by scanning electron microscopy. The analysis results are as follows: Figures 2-4 As shown, Figure 2 The image shown is a SEM image of the electrode material product prepared in Example 3 at 50x magnification. Figure 3 The image shown is a SEM image of the electrode material product prepared in Example 3 at 100x magnification. Figure 4 The image shown is a SEM image of the electrode material product prepared in Example 3 at 1000x magnification. Figure 2 a, Figure 3 a and Figure 4 a is a SEM image of the front side of the electrode material product prepared in Example 3 under corresponding magnification conditions. Figure 2 b、 Figure 3 b and Figure 4 b is a SEM image of the back side of the electrode material product prepared in Example 3 under corresponding magnification conditions.

[0071] from Figure 2 and Figure 3 As can be seen, under the same multiple conditions, the pore size on the front side of the electrode material product prepared in Example 3 is larger than that on the back side. This structure, with pore sizes increasing or decreasing sequentially, makes it easier for bubbles to detach from the electrode material, thereby reducing the residence time of bubbles on the electrode material and lowering its overall energy consumption; from Figure 4 As can be seen, the electrode material product prepared in Example 3 has a rough surface with many small protrusions. This is because the surface of the electrode material product is grafted with hydrophilic groups generated by the reaction of dilute nitric acid and sintered semi-finished products. The electrode material product has a large number of active sites on its surface, which greatly improves the selectivity of the electrode material product.

[0072] To test the catalytic activity of the electrode material prepared by the preparation method provided in this application, the oxygen evolution reaction performance of the electrode material product prepared in Example 3 and a commercially available electrode material product was tested below. The test results are as follows: Figure 5 As shown.

[0073] from Figure 5 As can be seen, under the same current density conditions, the voltage values ​​of the electrode material products prepared in Example 3 are all lower than those of commercially available electrode material products. Therefore, compared with commercially available electrode material products, the electrode material products prepared in Example 3 have lower energy consumption.

[0074] In summary, the electrode material prepared by the low-energy-consumption and high-selectivity foam metal electrode material preparation method provided in this application has the characteristics of low energy consumption, high selectivity and excellent electrochemical performance.

[0075] The foregoing provides a detailed description of a low-energy-consumption and high-selectivity foam metal electrode material preparation method and its application. Specific examples have been used to illustrate the principles and implementation methods of this application; the descriptions of these embodiments are merely for the purpose of helping to understand the core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A method for preparing a low-energy-consumption and highly selective foamed metal electrode material, characterized in that, The method includes: S100, bonding and conductive treatment: The selected sponges of different specifications are bonded together by a sponge adhesive mixed with metal powder, and the bonded sponges are then treated to make a layer of conductive metal spread on the surface of the sponge filaments. S200, Electroplating: Electroplating the conductive sponge based on a pre-prepared electroplating solution, and cleaning the electroplated semi-finished product. S300, Sintering: The electroplated semi-finished product is fully combusted in an oxygen atmosphere to remove the sponge skeleton, and then the metal is reduced in a hydrogen atmosphere to convert the oxidized metal into the reduced pure metal. S400 Activation: Under an inert gas atmosphere, the sintered semi-finished product is immersed in dilute nitric acid to react, and the hydrophilic groups generated by the reaction are grafted onto the surface of the sintered semi-finished product to obtain a low-energy-consumption and high-selectivity foam metal electrode material.

2. The preparation method according to claim 1, characterized in that, The different specifications of sponges in step S100 refer to sponges with different pore sizes.

3. The preparation method according to claim 2, characterized in that, The specific steps of step S100 are as follows: First, select sponges with decreasing or increasing pore sizes; then, apply a sponge adhesive mixed with metal powder evenly to the bonding surface of the selected sponges to ensure full bonding; finally, use magnetron sponge technology or chemical plating technology to evenly coat the surface of the bonded sponge fibers with a layer of conductive metal.

4. The preparation method according to claim 3, characterized in that, In step S200, the pre-prepared electroplating solution has a pH value of 5-9, and the electroplating solution is one of nickel electroplating solution, molybdenum electroplating solution or cobalt electroplating solution.

5. The preparation method according to claim 4, characterized in that, In step S200, electroplating the conductive sponge based on the pre-configured electroplating solution specifically involves setting two anodes on both sides of the cathode, and setting different current densities on both sides of the cathode based on the pre-configured electroplating solution and the sponge, so as to plate a metal coating of corresponding thickness at the sponge bonding point. The electroplating time is 1-30 min, and the current density is 1-80 ASD.

6. The preparation method according to claim 5, characterized in that, In step S200, cleaning the electroplated semi-finished product after electroplating specifically involves rinsing the electroplated semi-finished product with pure water 2-4 times.

7. The preparation method according to claim 6, characterized in that, In step S300, the temperature for complete combustion in an oxygen atmosphere is 300-700℃, and the combustion time is 1-10 minutes.

8. The preparation method according to claim 7, characterized in that, In step S300, a three-stage metal reduction is performed under a hydrogen atmosphere. The first stage reduction temperature is 300-900℃ and the reduction time is 1-3 min. The second stage reduction temperature is 200-600℃ and the reduction time is 2-9 min. The third stage reduction temperature is 100-300℃ and the reduction time is 1-5 min.

9. The preparation method according to claim 8, characterized in that, In step S400, the inert gas is at least one of nitrogen, helium, and argon.

10. An application of a low-energy-consumption and high-selectivity foamed metal electrode material, characterized in that, The low-energy-consumption and high-selectivity foam metal electrode material prepared by the preparation method according to any one of claims 1-9 is applied to the water electrolysis hydrogen production electrode, thereby obtaining a low-energy-consumption and high-selectivity water electrolysis hydrogen production electrode.

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