A method for preparing alloy thin film supported noble metal electrode for alkaline hydrogen evolution

Abstract

This invention belongs to the field of materials preparation technology and discloses a method for preparing an alloy thin film-supported noble metal electrode for alkaline hydrogen evolution. The preparation method is as follows: First, a nickel-iron alloy thin film is grown on nickel foam by constant current deposition. Then, it is immersed in a ruthenium trichloride aqueous solution. Under the action of the nickel foam, trivalent ruthenium ions are reduced to metallic ruthenium, which is anchored on the alloy thin film in the form of ruthenium nanoparticle clusters. The sample has an ultra-low ruthenium loading. The alloy thin film obtained by this invention is smooth and uniform, which is conducive to the uniform distribution of active sites and accelerates electron transfer. At the same time, by controlling the immersion conditions to load ruthenium nanoclusters of appropriate size, the hydrogen evolution reaction is promoted. Furthermore, the synergistic effect between the ruthenium nanoclusters and the nickel-iron alloy optimizes the hydrogen adsorption process and improves the hydrogen evolution reaction kinetics of the material. The self-supported catalyst obtained by this invention has excellent performance, superior to Pt / C catalysts, and maintains excellent stability even at industrial-grade high current densities, showing broad application prospects.

Description

Technical Field

[0001] This invention belongs to the field of materials preparation technology and relates to a method for preparing an alloy thin film-loaded noble metal electrode for alkaline hydrogen evolution. Background Technology

[0002] The over-reliance on fossil fuels in traditional energy systems has led to two major global problems: the depletion of non-renewable energy sources and the degradation of the ecological environment. Against this backdrop, the development of clean and renewable energy is crucial. Hydrogen energy, with its high energy density, zero carbon emissions, and storability, is a potential candidate for future low-carbon energy systems. Compared to methods such as hydrogen production through natural gas / fossil fuel reforming, electrochemical water splitting technology uses renewable electricity for electrocatalytic water splitting, enabling the sustainable production of green hydrogen and offering both environmental friendliness and economic advantages. Notably, alkaline water electrolysis systems, by avoiding corrosion and safety risks in acidic media, possess lower costs and higher stability, making them more promising for industrial applications. The hydrogen evolution reaction, a key half-reaction in water electrolysis, faces kinetic obstacles in actual water dissociation processes, and under alkaline conditions, *H is obtained from the initial water dissociation (H₂O + e⁻). – →*H+OH – This introduces an additional energy barrier. Therefore, it is necessary to develop electrocatalysts that combine high activity, stability, and cost-effectiveness to improve the reaction kinetics and energy conversion efficiency of the alkaline hydrogen evolution reaction.

[0003] Platinum-based catalysts are classic materials for the hydrogen evolution reaction (HER), but they suffer from inherent drawbacks in large-scale applications: high cost, scarce reserves, and poor stability. In contrast, ruthenium, with its similar hydrogen bond energy to platinum and a more significant cost advantage, shows great potential to replace platinum-based catalysts in alkaline HER. Studies have confirmed that ruthenium nanoparticles anchored on carbon, metal, and half-metal supports exhibit excellent HER performance. For example, the nitrogen-doped carbon-supported ruthenium ultrafine nanoparticle HER electrocatalyst (Ru / NC) obtained by a one-step thermal sintering method disclosed in CN118910647A achieves 10 mA cm⁻¹ in 1M KOH solution. -2 The overpotential required at the current density is 27 mV, comparable to that of Pt / C (26 mV). However, the preparation of this catalyst relies on long-term high-temperature processing, resulting in high energy consumption. Furthermore, ruthenium nanoparticles on carbon-based materials are prone to detaching from the support surface under sustained high potentials, leading to activity decay and limiting its large-scale application at high industrial current densities. CN118996494A discloses a hydrogen evolution electrocatalyst (Ru@TiC) in which ruthenium nanoparticles are supported on titanium carbide nanofibers through electrospinning and rapid Joule heat treatment. By leveraging the high specific surface area support and the metal-support interaction between ruthenium and carbide, uniform loading of ruthenium nanoparticles and an overpotential exceeding 500 mA cm⁻¹ are achieved. -2Stable hydrogen evolution performance at high current densities. However, the synthesis process of titanium carbide nanofibers is complex and costly, requiring multiple steps including electrospinning and carbonization, involving high-temperature treatment and inert atmosphere control, placing high demands on equipment. Furthermore, the ruthenium loading in the sample material is 0.5-30% wt., significantly increasing the cost of the catalyst. Addressing the problems inherent in most carbon-based supports for loading ruthenium nanoparticles, this invention involves in-situ growth of active components on a conductive, porous three-dimensional substrate to construct a self-supporting electrode. The preparation process is simple, abandoning traditional high-temperature treatment procedures, requiring less sophisticated equipment, and resulting in a tight bond between the support and the active component, facilitating electrolyte / electrocatalyst contact, accelerating charge transfer, and maintaining structural stability at high current densities. Introducing iron to construct a nickel-iron alloy support promotes uniform distribution of ruthenium nanoparticles and modulates the electronic structure of nickel sites, promoting hydrogen generation while simultaneously improving the material's conductivity and accelerating charge transfer. Moreover, this invention reduces the loading of precious metals, maintaining excellent catalytic activity while lowering catalyst costs, demonstrating both economic viability and potential for large-scale application.

[0004] Therefore, this invention employs a two-step electrodeposition-impregnation method. Using nickel foam as a substrate, a nickel-iron alloy film is first obtained by electrodeposition on the nickel foam, followed by impregnation in a ruthenium salt solution. The nickel foam substrate reduces trivalent ruthenium ions to metallic ruthenium, which is then loaded onto the alloy film in the form of nanoparticle clusters, successfully obtaining a highly efficient hydrogen evolution electrocatalytic electrode with ultra-low ruthenium content. The smooth and uniform nickel-iron alloy film facilitates the uniform distribution of active sites and promotes electron transfer. Simultaneously, the appropriately sized ruthenium nanoclusters exhibit excellent hydrogen evolution performance, and the synergistic effect between ruthenium and the nickel-iron alloy optimizes the hydrogen adsorption process, further enhancing the material's hydrogen evolution performance. This invention utilizes a simple method and reduces the cost of hydrogen evolution reaction catalysts in alkaline media, achieving high efficiency at industrial-grade current densities (>500 mA cm⁻¹). -2 It also exhibits excellent catalytic activity and long-term stability, and has broad prospects for industrial application. Summary of the Invention

[0005] This invention addresses the problems of high cost and difficulty in maintaining stability under high current densities and long-term electrocatalytic operation of platinum-based catalysts. It provides a method for preparing an alloy thin-film supported noble metal electrode for alkaline hydrogen evolution. The prepared catalytic electrode can withstand high current densities (>500 mA cm⁻¹). -2 It also has excellent catalytic performance and can operate stably for 50 hours.

[0006] The technical solution of the present invention:

[0007] A method for preparing an alloy thin film-supported noble metal electrode for alkaline hydrogen evolution includes the following steps:

[0008] (1) Cut the foamed nickel, and ultrasonically clean it in dilute hydrochloric acid, anhydrous ethanol and deionized water in sequence to remove organic pollutants and oxides on the surface. After drying, clean foamed nickel is obtained.

[0009] (2) Using a three-electrode system, clean foamed nickel is placed into the electroplating solution, and nickel-iron alloy is electrodeposited using the constant current IT method. After completion, the foamed nickel is removed, rinsed with anhydrous ethanol and deionized water, and dried.

[0010] (3) After the dried nickel foam is soaked in ruthenium salt solution for a period of time, it is taken out, rinsed with anhydrous ethanol and deionized water, and dried to obtain nickel-iron alloy thin film loaded noble metal electrode.

[0011] In step (1), the molar concentration of the dilute hydrochloric acid is 1 to 6 M.

[0012] In step (2), the electroplating solution is obtained by uniformly mixing deionized water, nickel salt, iron salt and sodium citrate; wherein the nickel salt is nickel chloride, nickel sulfate or nickel nitrate, with a molar concentration of 0.05-0.5M; the iron salt is ferric chloride, ferric sulfate or ferric nitrate, with a molar concentration of 5-100mM; and the molar concentration of sodium citrate is 0.05-0.5M.

[0013] In step (2), the three-electrode system uses clean nickel foam as the working electrode, a graphite rod as the counter electrode, and a saturated calomel electrode as the reference electrode, with a current density of -60 to -140 mA / cm². -2 The electrodeposition time is 180–600 s.

[0014] In step (3), the ruthenium salt is ruthenium chloride, ruthenium nitrate, or ruthenium acetate, wherein the solution concentration is 0.5–5 mg / mL. -1 The soaking time is 1 to 5 hours.

[0015] The alloy thin film-loaded noble metal electrode described in this invention forms a three-electrode system for efficient hydrogen evolution reaction in alkaline electrolytes.

[0016] The beneficial effects of this invention are:

[0017] (1) The present invention adopts a simple electrodeposition-impregnation preparation method, using a three-dimensional conductive material as a substrate to prepare a self-supporting electrode, which promotes the contact between the electrolyte and the catalyst, and achieves a tight bond between the active component and the substrate material through chemical bonding. The resulting electrode material has both high catalytic activity and good stability.

[0018] (2) The catalyst prepared by this invention has a noble metal loading of less than 0.5% wt., which reduces the amount of noble metal used and lowers the cost of the catalyst.

[0019] (3) The alloy thin film carrier formed on the surface of the nickel foam in this invention is smooth and uniform, which is conducive to the uniform dispersion of active sites. At the same time, the ruthenium nanoparticle clusters obtained by controlling the impregnation conditions have a suitable particle size, which accelerates the hydrogen evolution reaction. In addition, the synergistic effect between the ruthenium nanoparticle clusters and the nickel-iron alloy optimizes the hydrogen adsorption process and further improves the performance of the material.

[0020] (4) The active component in the high-efficiency hydrogen evolution catalyst prepared in this invention is tightly bonded to the substrate material, making it difficult to detach even at high current densities. Electrochemical tests were performed in 1M KOH at 500 mA cm⁻¹. -2 This invention requires only ultra-low overpotential (<150mV) at industrial-grade current densities and can operate stably for 50 hours. It provides new opportunities for hydrogen production via alkaline water electrolysis at high current densities and has broad prospects for industrial applications. Attached Figure Description

[0021] Figure 1 The flowchart shows the preparation process of Ru / NiFe / NF.

[0022] Figure 2 Scanning electron microscope (SEM) images of the materials in Example 1, wherein (a) is an SEM image of NF, (b) is an SEM image of NiFe / NF, and (c) is an SEM image of Ru / NiFe / NF.

[0023] Figure 3 This is a high-resolution transmission electron microscope image of Ru / NiFe / NF prepared in Example 1.

[0024] Figure 4 (a) shows the Ru / NiFe / NF of Example 1, Ru / NiFe / NF-1 of Example 2, and Ru / NiFe / NF-2 of Example 3; (b) shows the linear sweep voltammetry curves of Ru / NiFe / NF of Example 1, Ru / NiFe / NF-3 of Example 4, Ru / NiFe / NF-4 of Example 5, and Ru / NiFe / NF-5 of Example 6 in 1M KOH solution at 25°C.

[0025] Figure 5 Linear sweep voltammetry curves of Ru / NiFe / NF in Example 1, Ru / NF in Comparative Example 1, Ru / Ni / NF in Comparative Example 2, and Pt / C in Comparative Example 3 at 25°C in 1M KOH solution.

[0026] Figure 6 Tafel slopes of Ru / NiFe / NF in Example 1, Ru / NF in Comparative Example 1, Ru / Ni / NF in Comparative Example 2, and Pt / C in Comparative Example 3 at 25°C in 1M KOH solution.

[0027] Figure 7 The image shows the linear scanning voltammetry curves of Ru / NiFe / NF before and after 1000 CV scans for Example 1.

[0028] Figure 8 For Example 1, Ru / NiFe / NF was tested in 1M KOH solution at 25°C at -100 and -500 mA cm⁻¹. -2 Timing potential diagram under current density. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0030] Example 1

[0031] (1) Cut 1cm×1.5cm pieces of nickel foam and sonicate them in 3M HCl solution, anhydrous ethanol and deionized water for 20min respectively to remove surface oxides and oil stains. Then, place the cleaned NF in a vacuum drying oven at 60℃ and dry for 6h to obtain a clean nickel foam substrate.

[0032] (2) Dissolve 0.1M nickel chloride, 0.01M ferric chloride and 0.1M sodium citrate in 50mL of deionized water and stir to form a homogeneous aqueous solution.

[0033] (3) A three-electrode system was used, with the solution prepared in step (2) as the electroplating solution, clean nickel foam as the working electrode, a stone rod as the counter electrode, and a saturated calomel electrode as the reference electrode, at 30℃ and -80mA cm⁻¹. -2 A constant current deposition was performed for 360 s. The sample was then rinsed with anhydrous ethanol and deionized water, and dried in a vacuum oven at 60 °C for 6 h to obtain NiFe / NF.

[0034] (4) Prepare 1.5 mg mL -1 Ruthenium trichloride aqueous solution was used as the impregnation solution. The dried NiFe / NF was immersed in the impregnation solution for 2 hours, then rinsed with anhydrous ethanol and deionized water, and dried under vacuum at 60°C for 6 hours to obtain Ru / NiFe / NF.

[0035] The Ru loading of the catalyst was determined to be 0.122 mg / cm³ by inductively coupled plasma atomic emission spectrometry. 2 It has an ultra-low Ru load.

[0036] The obtained electrodes were subjected to electrochemical performance tests in a three-electrode system, with a graphite rod as the counter electrode, Hg / HgO as the reference electrode, 1M KOH as the electrolyte solution, and room temperature (25℃). Linear sweep voltammetry (LSV) was performed with an initial scan potential of -0.924V (vs. Hg / HgO), and chronopotentiometric voltammetry (CP) was performed at -100 and -500 mA cm⁻¹, respectively. -2 A durability test was conducted for 50 hours at a current density.

[0037] The results are as follows: Figure 2 These are scanning electron microscope (SEM) images; (a) is NF, (b) is NiFe / NF, and (c) is Ru / NiFe / NF. The SEM images show that a smooth and uniform nickel-iron alloy film is uniformly grown on the NF substrate, and ruthenium spherical nanoparticle clusters are uniformly dispersed on the NiFe / NF surface. Figure 3 The image is a high-resolution transmission electron microscope image of Ru / NiFe / NF from Example 1. Clear lattice fringes with spacings of 0.211 nm, 0.204 nm, and 0.207 nm can be observed, corresponding to the (002) and (111) planes of Ru and the (111) plane of the NiFe alloy, respectively. Figure 4 The LSV diagrams are for the samples prepared in Examples 1-6. Figure 5 The LSV plots of the samples prepared in Example 1 and Comparative Examples 1-3 show that the Ru / NiFe / NF prepared in Example 1 exhibits the best hydrogen evolution performance, reaching 100 and 500 mA cm⁻¹. -2 The current density requires only low overpotentials of 67 and 147 mV. Figure 6 The Tafel slope plots of the samples prepared in Example 1 and Comparative Examples 1-3 show that the Ru / NiFe / NF prepared in Example 1 has the lowest Tafel slope of 65.0 mV dec. -1 This indicates that it has faster reaction kinetics and higher catalytic activity. Figure 7 The image shows the linear scanning voltammetry curves of Ru / NiFe / NF prepared in Example 1 before and after 1000 CV scans. Figure 8 For its -100 and -500mA cm -2 The chronopotential curves at the current density for 50 hours show that there is no significant difference in the LSV curves of the sample before and after 1000 CV scans. In the chronopotential reaction, the potential only increases slightly as the reaction proceeds, which indicates that the sample has excellent stability.

[0038] Example 2

[0039] The difference between this embodiment and embodiment 1 is that the impregnation time in step (4) is 1 hour, while the other parameters and specific implementation steps are the same as in embodiment 1, resulting in Ru / NiFe / NF-1.

[0040] The Ru loading of the catalyst was determined to be 0.062 mg / cm³ by inductively coupled plasma atomic emission spectrometry. 2 .

[0041] This embodiment uses the same electrochemical testing method as Example 1, except that CP testing is not performed.

[0042] The results are as follows: Figure 4 (a) The Ru / NiFe / NF-1 prepared in Example 2 can be obtained with 100 and 500 mA cm⁻¹. -2 The required current densities are 97 and 194 mV, respectively. The performance is worse than that of Example 1, possibly due to the shorter impregnation time, the smaller amount of Ru loaded, the reduced number of active sites, and the lower catalytic activity.

[0043] Example 3

[0044] The difference between this embodiment and embodiment 1 is that the impregnation time in step (4) is 3 hours. Other parameters and specific implementation steps are the same as in embodiment 1, and Ru / NiFe / NF-2 is obtained.

[0045] The Ru loading of the catalyst was determined to be 0.201 mg / cm³ by inductively coupled plasma atomic emission spectrometry. 2 .

[0046] This embodiment uses the same electrochemical testing method as Example 1, except that CP testing is not performed.

[0047] The results are as follows: Figure 4 (a) The Ru / NiFe / NF-2 prepared in Example 3 can be obtained with 100 and 500 mA cm⁻¹. -2 The required current densities are 84 and 184 mV, respectively. The performance is slightly worse than that of Example 1. This may be because the nanoparticle clusters begin to aggregate after 3 hours of impregnation. Since the large-diameter Ru clusters have a relatively low surface atomic ratio, there are fewer active sites on their surface that can be used to bind H atoms, resulting in a weaker adsorption capacity for H atoms, which causes the catalyst performance to begin to decline.

[0048] Example 4

[0049] The difference between this embodiment and Embodiment 1 is that step (4) uses a ruthenium trichloride aqueous solution with a concentration of 5.0 mg / mL. -1 Other parameters and specific implementation steps are the same as in Example 1, resulting in Ru / NiFe / NF-3.

[0050] The Ru loading of the catalyst was determined to be 0.241 mg / cm³ by inductively coupled plasma atomic emission spectrometry. 2 .

[0051] This embodiment uses the same electrochemical testing method as Example 1, except that CP testing is not performed.

[0052] The results are as follows: Figure 4 (b) The Ru / NiFe / NF-3 prepared in Example 4 can achieve 100 and 500 mA cm⁻¹. -2 The required current densities are 94 and 184 mV, respectively. The poor performance is due to the high concentration of the impregnation solution, which loads too much Ru, causing a large number of nanoparticles to aggregate together, resulting in weak adsorption of H atoms and low catalytic activity.

[0053] Example 5

[0054] The difference between this embodiment and embodiment 1 is that the electrodeposition time in step (3) is 600s, while the other parameters and specific implementation steps are the same as in embodiment 1, resulting in Ru / NiFe / NF-4.

[0055] This embodiment uses the same electrochemical testing method as Example 1, except that CP testing is not performed.

[0056] The results are as follows: Figure 4 (b) The Ru / NiFe / NF-4 prepared in Example 5 can be obtained with 100 and 500 mA cm⁻¹. -2 The required current densities are 92 and 170 mV, respectively. The performance is slightly inferior compared to Example 1, which may be due to the excessively long electrodeposition time leading to a thicker alloy coating, increased interfacial resistance, and obstructed electron transport paths, resulting in a decrease in the catalytic activity of the material.

[0057] Example 6

[0058] The difference between this embodiment and embodiment 1 is that the molar concentration of ferric chloride in step (2) is 0.1M. Other parameters and specific implementation steps are the same as in embodiment 1, resulting in Ru / NiFe / NF-5.

[0059] This embodiment uses the same electrochemical testing method as Example 1, except that CP testing is not performed.

[0060] The results are as follows: Figure 4 (b) The Ru / NiFe / NF-5 prepared in Example 6 can achieve 100 and 500 mA cm⁻¹. -2 The required current densities were 119 and 226 mV, respectively. The main reason for the poor performance of this sample was the excessive doping of iron. When the iron content is too high, it will change the electronic structure of the alloy, weaken the mechanical stability of the material and reduce the conductivity, ultimately causing the catalytic performance to decline.

[0061] Comparative Example 1

[0062] The difference between this comparative example and Example 1 is that the dried NF was directly immersed in ruthenium trichloride impregnation solution for 2 hours to obtain Ru / NF.

[0063] This comparative example uses the same electrochemical testing method as Example 1, except that CP testing is not performed.

[0064] The results are as follows: Figure 5 The LSV plots of the samples prepared in Example 1 and Comparative Examples 1-3 show that the Ru / NF ratio of the sample prepared in Comparative Example 1 reached 100 and 500 mA cm⁻¹. -2 The required current densities are 268 and 358 mV respectively, which require high overpotentials. Figure 6 The images show the Tafel slopes of the samples prepared in Example 1 and Comparative Examples 1-3, with the Tafel slope of Ru / NF prepared in Comparative Example 1 being 156.8 mVdec. -1 It can be seen that the performance of Comparative Example 1 is far worse than that of Example 1. The reason may be that there is a synergistic effect between ruthenium and nickel-iron alloy in Example 1, which optimizes the hydrogen adsorption process, while there is no such interaction in Comparative Example 1, resulting in its poor hydrogen evolution performance.

[0065] Comparative Example 2

[0066] The difference between this comparative example and Example 1 is that ferric chloride is not added to the electroplating solution in step (2), resulting in Ru / Ni / NF.

[0067] This comparative example uses the same electrochemical testing method as Example 1, except that CP testing is not performed.

[0068] The results are as follows: Figure 5 Comparative Example 2 yielded Ru / Ni / NF with 100 and 500 mA cm⁻¹ values. -2 The required current densities are 175 and 310 mV, respectively, which require higher overpotentials. Figure 6 The Tafel slope of the Ru / Ni / NF prepared in Comparative Example 2 was 137.7 mVdec. -1 It can be seen that while Comparative Example 2 performs better than Comparative Example 1, it is still far inferior to Example 1. This is likely because Fe was incorporated into Example 1, leading to a bimetallic effect between the nickel and iron alloys. Furthermore, the addition of iron modulates the electronic structure of the nickel sites, promoting hydrogen generation. In addition, the addition of a small amount of iron improves the conductivity of the sample, effectively promoting charge transport kinetics at the electrode interface. In contrast, the Ru / Ni / NF prepared in Comparative Example 2 does not contain iron and therefore lacks these advantages, resulting in limited overall catalytic performance.

[0069] Comparative Example 3

[0070] (1) Cut carbon paper (CP) to 1cm×1.5cm and sonicate it twice in a mixed solution of deionized water and anhydrous ethanol (V1:V2=1:1) for 20min each time to remove surface oil. Then rinse it with deionized water and dry it in a vacuum drying oven at 60℃ for 6h to obtain clean carbon paper.

[0071] (2) 5 mg of Pt / C powder was dispersed in a mixed solution containing 460 μL of anhydrous ethanol and 40 μL of 5 wt.% Nafion 117. After ultrasonic dispersion for 30 min, a uniform ink-like liquid was obtained.

[0072] (3) Use a pipette to draw 200 μL of the liquid from step (2) and drop it onto a surface with an area of ​​1 cm². 2 The Pt / C working electrode is obtained by drying the clean carbon paper on it overnight in a vacuum drying oven at 60°C.

[0073] This comparative example uses the same electrochemical testing method as Example 1, except that CP testing is not performed.

[0074] The results are as follows: Figure 5 The Pt / C prepared in Comparative Example 3 can achieve 100 and 500 mA cm⁻¹. -2 The required current densities are 76 and 232 mV overpotentials, respectively. Figure 6 The Tafel slope of the Pt / C prepared in Comparative Example 3 was 74.9 mV dec. -1 It can be seen that the performance of Comparative Example 3 is lower than that of Example 1, meaning that the Ru / NiFe / NF prepared in Example 1 has the best catalytic performance, which is superior to the commercial Pt / C hydrogen evolution catalyst.

[0075] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent transformations made based on the content of the present invention under the concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for preparing an alloy thin film-supported noble metal electrode for alkaline hydrogen evolution, characterized in that, The steps are as follows: (1) Cut the foamed nickel, and ultrasonically clean it in dilute hydrochloric acid, anhydrous ethanol and deionized water in sequence to remove organic pollutants and oxides on the surface. After drying, clean foamed nickel is obtained. (2) Using a three-electrode system, clean foamed nickel is placed into the electroplating solution, and nickel-iron alloy is electrodeposited using the constant current IT method. After completion, the foamed nickel is removed, rinsed with anhydrous ethanol and deionized water, and dried. (3) After the dried nickel foam is soaked in ruthenium salt solution for a period of time, it is taken out, rinsed with anhydrous ethanol and deionized water, and dried to obtain nickel-iron alloy thin film loaded noble metal electrode.

2. The preparation method according to claim 1, characterized in that, In step (1), the molar concentration of the dilute hydrochloric acid is 1 to 6 M.

3. The preparation method according to claim 1, characterized in that, In step (2), the electroplating solution is obtained by uniformly mixing deionized water, nickel salt, iron salt and sodium citrate; wherein the nickel salt is nickel chloride, nickel sulfate or nickel nitrate, with a molar concentration of 0.05-0.5M; the iron salt is ferric chloride, ferric sulfate or ferric nitrate, with a molar concentration of 5-100mM; and the molar concentration of sodium citrate is 0.05-0.5M.

4. The preparation method according to claim 1, characterized in that, In step (2), the three-electrode system uses clean nickel foam as the working electrode, a graphite rod as the counter electrode, and a saturated calomel electrode as the reference electrode, with a current density of -60 to -140 mA / cm². -2 The electrodeposition time is 180–600 s.

5. The preparation method according to claim 1, characterized in that, In step (3), the ruthenium salt is ruthenium chloride, ruthenium nitrate, or ruthenium acetate, wherein the solution concentration is 0.5–5 mg / mL. -1 The soaking time is 1 to 5 hours.

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