Bimetallic sulfide integral electrode with modified stainless steel surface on a square meter scale, preparation method and application

Abstract

This invention belongs to the field of water electrolysis for hydrogen production technology. It discloses a square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode, its preparation method, and its application. The preparation method includes the following steps: (1) ultrasonically cleaning a stainless steel substrate sequentially with deionized water, acetone, and ethanol, immersing it in a dilute hydrochloric acid solution under heat, and finally rinsing it with deionized water and drying it to obtain a clean stainless steel substrate; (2) dissolving two transition metal cation salts and a sulfur source in an aqueous solution and stirring at room temperature to mix them evenly; (3) placing the clean stainless steel substrate obtained in step (1) into the solution in step (2) and heating it to react. After the reaction is completed, the resulting sample is washed with water and dried. The advantages of this invention are low cost, simple process, excellent catalytic activity and stability of the prepared integrated electrode, and the ability to prepare it on a square meter scale, making it suitable for large-scale industrial alkaline water electrolysis for hydrogen production.

Description

Technical Field

[0001] This invention belongs to the field of water electrolysis for hydrogen production technology, specifically relating to a square meter-scale stainless steel surface-modified integrated electrode formed by transition metal sulfidation and its application in water electrolysis. It provides a simple and low-cost method for preparing an electrode suitable for industrial-scale water electrolysis for hydrogen production. Background Technology

[0002] As my country's economy shifts from a high-speed growth model to a high-quality development model, the construction of a clean, low-carbon, safe, and efficient energy system has become increasingly urgent. Hydrogen energy possesses extremely high energy density (283 kJ / mol). -1 Hydrogen production via water electrolysis is an ideal, efficient, and clean renewable energy source, with water as the only combustion product. This technology stores electricity generated from renewable clean energy sources such as solar, wind, and tidal power as hydrogen energy, thus achieving a cleaner and lower-carbon hydrogen energy industry throughout its entire lifecycle. This plays a crucial role in the overall cleanliness and decarbonization of the hydrogen energy industry. The entire water electrolysis process is divided into the hydrogen evolution reaction (HER) at the cathode and the oxygen evolution reaction (OER) at the anode. Both HER and OER electrochemical processes occur at the gas-solid-liquid three-phase interface, involving reactant diffusion, adsorption, activation, formation and conversion of reaction intermediates, product desorption, and charge transfer. These steps have slow reaction kinetics and high reaction barriers, severely limiting the efficiency and lifespan of hydrogen production from water electrolysis. Currently, the most ideal catalysts for HER and OER are noble metal Pt-based and RuO2 / IrO2-based materials, respectively. However, the scarcity, high cost, and poor long-term stability of noble metal electrocatalysts greatly hinder their large-scale application. Therefore, there is an urgent need to develop inexpensive, efficient, and long-lasting non-precious metal-based electrocatalysts to reduce reaction energy barriers and accelerate interfacial reaction kinetics. This is crucial for improving the efficiency of hydrogen production through water electrolysis and reducing hydrogen production costs, and is also one of the key scientific problems that urgently need to be solved.

[0003] Among the numerous non-precious metal-based catalytic materials for water electrolysis, transition metal sulfides are considered one of the most promising noble metal alternative catalysts in the field of water electrolysis due to their abundant reserves, low price, tunable morphology and composition, diverse crystal structures, and good stability. Furthermore, since the electrochemical hydrogen evolution process involves a liquid-solid-gas three-phase interface, the catalytic electrode itself not only needs to possess good catalytic activity but also requires good conductivity and a three-dimensional porous structure to improve the mass transfer of reactants and products, as well as gas diffusion. This characteristic is particularly important under high current conditions, necessitating optimization and treatment of the overall structure and surface of the catalytic electrode. Finally, current water electrolysis for hydrogen production mainly takes place in alkaline electrolytes, but strong alkaline solutions cause significant corrosion to the electrolyzer and catalyst, and powdered catalysts often undergo dissolution and shedding during the reaction, leading to activity degradation. Therefore, there is an urgent need for a low-cost, high-efficiency, simple-process, and square-scale integrated electrode to meet the needs of large-scale industrial water electrolysis for hydrogen production. Summary of the Invention

[0004] To address the problems existing in the aforementioned technologies, this invention provides a method for preparing a square meter-scale stainless steel surface-modified bimetallic integral electrode for hydrogen production via water electrolysis. The advantages of this invention are low cost, simple process, excellent catalytic activity and stability of the prepared integral electrode, and the ability to achieve square meter-scale preparation, making it suitable for large-scale industrial alkaline water electrolysis for hydrogen production.

[0005] The specific technical solution of the present invention is as follows:

[0006] A bimetallic sulfide integrated electrode with a square meter-scale stainless steel surface modification has an ultrathin nanosheet-encapsulated microsphere structure. The ultrathin nanosheet is nickel-iron sulfide, and the microsphere is elemental sulfur. The ultrathin nickel-iron sulfide nanosheet-encapsulated sulfur microsphere material is uniformly distributed on the stainless steel surface.

[0007] Furthermore, the thickness of the ultrathin nanosheets is 5–50 nm; the diameter of the microspheres is 5–50 μm.

[0008] Furthermore, a one-step hydrothermal method was used for preparation.

[0009] A method for preparing a square meter-scale stainless steel surface-modified bimetallic sulfide integral electrode includes the following steps:

[0010] (1) The stainless steel substrate was ultrasonically cleaned with deionized water, acetone and ethanol in sequence, then heated and soaked in dilute hydrochloric acid solution, and finally rinsed with deionized water and dried to obtain a clean stainless steel substrate.

[0011] (2) Dissolve the two transition metal cation salts and the sulfur source in an aqueous solution and stir at room temperature to make them evenly mixed;

[0012] (3) Place the clean stainless steel substrate obtained in step (1) into the solution in step (2) and heat it to react. After the reaction is completed, wash the obtained sample with water and dry it to obtain the square meter-scale stainless steel surface modified bimetallic sulfide integrated electrode.

[0013] Furthermore, in step (1), the ultrasonic cleaning time is 5-20 min; the concentration of dilute hydrochloric acid is 1-5 mol / L. -1 The acid leaching temperature is 50~80 ℃, and the acid leaching time is 1~8 h.

[0014] Furthermore, in step (2), the transition metal cation salt is at least one of the transition metal cations, nitrates, sulfates, chlorides, carbonates, or acetates; the metal cation is at least two of titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, or molybdenum; the sulfur source is at least one of thiourea, thioacetamide, sodium sulfide, thiophenol, thiol, or thioether; in the solution, the molar ratio of sulfur anion to transition metal cation is 1:5 to 5:1; wherein the molar ratio of the two transition metal cations is 1:4 to 4:1.

[0015] Furthermore, in step (2), the stirring time at room temperature is 30~120 min.

[0016] Furthermore, in step (3), the reaction temperature is 60~100 °C; the reaction time is 12~24 h; the drying temperature is 30~100 °C; and the drying time is 1~6 h.

[0017] The application of a square meter-scale stainless steel surface-modified bimetallic sulfide integral electrode as an integral electrode material in electrocatalytic reactions.

[0018] Furthermore, the electrocatalytic reaction is a water electrolysis reaction to produce hydrogen.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. The square meter-scale stainless steel surface-modified bimetallic sulfidation integrated electrode provided by the present invention directly sulfidates the stainless steel surface with transition metal and sulfur source, and the resulting integrated electrode has good electrochemical activity and stability. The sulfides on the stainless steel surface are not easy to fall off and have a long service life.

[0021] 2. The square meter-scale stainless steel surface-modified bimetallic sulfidation integrated electrode prepared by this invention has a flexible adjustable ratio of metal cations and sulfur anions, and the types and ratios of the two metal cations can also be adjusted. It has a wide range of applications, the conditions are easy to control, and it is easy to operate.

[0022] 3. The preparation method provided by this invention uses stainless steel as a substrate, which is low in cost, simple in process, easy to control reaction conditions, and can achieve preparation on a square meter scale. It is suitable for large-scale industrial electrolysis of water to produce hydrogen.

[0023] 4. The square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode material prepared by this invention exhibits superior catalytic performance in the electrocatalytic water splitting oxygen evolution system. These advantages make this electrode a promising candidate for industrialization of water electrolysis for hydrogen production. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the 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 based on these drawings without creative effort.

[0025] Figure 1 The images show scanning electron microscope (SEM) images of different scales of the square meter-scale stainless steel integrated electrode in Example 1.

[0026] Figure 2 This is a transmission electron microscope (TEM) image of the square meter-scale stainless steel integrated electrode in Example 1 and its elemental distribution diagram.

[0027] Figure 3 This is a high-resolution transmission electron microscope (HRTEM) image of the square meter-scale stainless steel integrated electrode in Example 1.

[0028] Figure 4 X-ray diffraction (XRD) characterization of the square meter-scale stainless steel monolithic electrode in Example 1.

[0029] Figure 5 This is a large-area fabrication diagram of the square meter-scale stainless steel integrated electrode in Example 1.

[0030] Figure 6 The graphs show the performance of Examples 1, 2, and 3 in the electrocatalytic water splitting and oxygen evolution reaction.

[0031] Figure 7 The graphs show the performance of Examples 1, 4, and 5 in the electrocatalytic water splitting and oxygen evolution reaction.

[0032] Figure 8 This is a stability constant current diagram of Example 1 in the electrocatalytic water splitting and oxygen evolution reaction. Detailed Implementation

[0033] The preparation process of this application will be described in detail below through examples, but the scope of protection claimed by this application is not limited to the following examples.

[0034] The bimetallic sulfide integrated electrode for modifying stainless steel surface on a square meter scale of the present invention has an ultrathin nanosheet-encapsulated microsphere structure, wherein the ultrathin nanosheet is nickel-iron sulfide, the microsphere is elemental sulfur, and the ultrathin nickel-iron sulfide nanosheet-encapsulated sulfur microsphere material is uniformly distributed on the stainless steel surface.

[0035] The nanosheets have a thickness of 5–50 nm and are composed of nickel iron sulfide.

[0036] The microspheres have a diameter of 5–50 μm and are composed of elemental sulfur.

[0037] The square meter-scale stainless steel surface-modified bimetallic sulfide integral electrode material is prepared by a simple one-step hydrothermal method.

[0038] The method for preparing the square meter-scale stainless steel surface-modified bimetallic sulfide integral electrode of the present invention includes the following specific preparation steps:

[0039] The stainless steel substrate was ultrasonically cleaned sequentially with deionized water, acetone, and ethanol for 5-20 minutes each.

[0040] The stainless steel substrate that has been ultrasonically cleaned in step (1) is then immersed in a dilute hydrochloric acid solution with a concentration of 1-5 mol / L. -1 The acid leaching time is 1~8 h, and the acid leaching temperature is 50~80 ℃; preferably, the acid leaching time is 2~6 h.

[0041] After acid leaching in step (2), the stainless steel substrate is rinsed with deionized water and dried to obtain a clean stainless steel substrate.

[0042] Two transition metal cation salts and a sulfur source are dissolved in an aqueous solution; preferably, the transition metal cation salts are nitrates of transition metal cations; preferably, the metal cations are iron and nickel; preferably, the sulfur source is thiourea.

[0043] In the solution, the molar ratio of sulfide anions to transition metal cations is 1:5 to 5:1; wherein the molar ratio of the two transition metal cations is 1:4 to 4:1.

[0044] Place the solution prepared in step (4) at room temperature and stir for 30 to 120 minutes to mix it evenly; preferably, the stirring time is 50 to 100 minutes.

[0045] Then, the clean stainless steel substrate obtained in step (3) is placed into the solution stirred in step (5) and heated to react; the reaction temperature is 60 ~ 100 °C and the reaction time is 12 ~ 24 h.

[0046] After the reaction in step (6) is completed, the sample is washed with water and dried at 30 ~ 100 ℃ for 1 ~ 6 h to obtain the square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode.

[0047] The products of Examples 1-4 of this invention were tested using the following instruments and methods:

[0048] The morphology of the product of Example 1 was characterized using scanning electron microscopy (SEM);

[0049] The morphology and elemental distribution of the product of Example 1 were characterized by transmission electron microscopy (TEM);

[0050] Structural information of Example 1 was analyzed by X-ray diffraction (XRD);

[0051] The oxygen production performance of water splitting in Examples 1-5 was determined in the electrocatalytic water electrolysis oxygen evolution system.

[0052] Examples 1, 2, and 3 show the molar ratio of two metal cations in the modified solution; Examples 1, 3, and 4 show the molar ratio of sulfide anions and metal cations in the modified solution.

[0053] Example 1

[0054] 1. Clean the stainless steel substrate sequentially with deionized water, acetone, and ethanol using ultrasonic cleaning for 10 minutes each.

[0055] 2. After ultrasonic cleaning in step 1, the stainless steel substrate is immersed in a 3 mol / L dilute hydrochloric acid solution under heat. -1 The acid leaching time was 4 hours and the acid leaching temperature was 60 ℃.

[0056] 3. After the acid leaching in step 2 is completed, the stainless steel substrate is rinsed with deionized water and dried to obtain a clean stainless steel substrate.

[0057] 4. Dissolve 1.5224 g thiourea, 1.4540 g nickel nitrate hexahydrate and 2.0200 g ferric nitrate nonahydrate in 20 ml of deionized water and mix well.

[0058] 5. Place the solution prepared in step 4 at room temperature and stir for 80 minutes to ensure it is thoroughly mixed.

[0059] 6. Then, the clean stainless steel substrate obtained in step 3 is placed into the solution stirred in step 5 and heated to react; the reaction temperature is 90 °C and the reaction time is 24 h.

[0060] 7. After the reaction in step 6 is completed, the sample is washed with water and dried at 60 °C for 2 h to obtain the square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode.

[0061] like Figure 1 and Figure 2 As shown, both scanning electron microscopy and transmission electron microscopy indicate that the synthesized square meter-scale stainless steel surface-modified bimetallic sulfide integral electrode possesses an ultrathin nanosheet-encapsulated microsphere structure, and the ultrathin nanosheet-encapsulated microspheres are uniformly distributed on the stainless steel surface. Figure 3 and Figure 4 As shown, high-resolution transmission electron microscopy combined with X-ray diffraction spectroscopy indicates that the ultrathin nanosheets are nickel-iron sulfide, and the microspheres are elemental sulfur. Figure 5 As shown, large-area fabrication of bimetallic sulfide monolithic electrodes with modified stainless steel surfaces on a square meter scale can be achieved. Figure 8 As shown, the bimetallic sulfide integrated electrode with stainless steel surface modification on a square meter scale can achieve high stability in the electrocatalytic water splitting and oxygen evolution reaction.

[0062] Example 2

[0063] 1. Clean the stainless steel substrate sequentially with deionized water, acetone, and ethanol using ultrasonic cleaning for 10 minutes each.

[0064] 2. After ultrasonic cleaning in step 1, the stainless steel substrate is immersed in a 3 mol / L dilute hydrochloric acid solution under heat. -1 The acid leaching time was 4 hours and the acid leaching temperature was 60 ℃.

[0065] 3. After the acid leaching in step 2 is completed, the stainless steel substrate is rinsed with deionized water and dried to obtain a clean stainless steel substrate.

[0066] 4. Dissolve 1.5224 g thiourea, 0.7270 g nickel nitrate hexahydrate and 3.0299 g ferric nitrate nonahydrate in 20 ml of deionized water and mix well.

[0067] 5. Place the solution prepared in step 4 at room temperature and stir for 80 minutes to ensure it is thoroughly mixed.

[0068] 6. Then, the clean stainless steel substrate obtained in step 3 is placed into the solution stirred in step 5 and heated to react; the reaction temperature is 90 °C and the reaction time is 24 h.

[0069] 7. After the reaction in step 6 is completed, the sample is washed with water and dried at 60 °C for 2 h to obtain the square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode.

[0070] Example 3

[0071] 1. Clean the stainless steel substrate sequentially with deionized water, acetone, and ethanol using ultrasonic cleaning for 10 minutes each.

[0072] 2. After ultrasonic cleaning in step 1, the stainless steel substrate is immersed in a 3 mol / L dilute hydrochloric acid solution under heat. -1 The acid leaching time was 4 hours and the acid leaching temperature was 60 ℃.

[0073] 3. After the acid leaching in step 2 is completed, the stainless steel substrate is rinsed with deionized water and dried to obtain a clean stainless steel substrate.

[0074] 4. Dissolve 1.5224 g thiourea, 2.1809 g nickel nitrate hexahydrate and 1.0099 g ferric nitrate nonahydrate in 20 ml of deionized water and mix well.

[0075] 5. Place the solution prepared in step 4 at room temperature and stir for 80 minutes to ensure it is thoroughly mixed.

[0076] 6. Then, the clean stainless steel substrate obtained in step 3 is placed into the solution stirred in step 5 and heated to react; the reaction temperature is 90 °C and the reaction time is 24 h.

[0077] 7. After the reaction in step 6 is completed, the sample is washed with water and dried at 60 °C for 2 h to obtain the square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode.

[0078] Results and Discussion: Under the same conditions (ratio of thiourea to metal cations, amount of water, and reaction in a 90°C oven for 24 h), Examples 1-3 showed that the ratio of the two metal cations in the solution was adjusted by changing the amount of metal salt added.

[0079] Example 4

[0080] 1. Clean the stainless steel substrate sequentially with deionized water, acetone, and ethanol using ultrasonic cleaning for 10 minutes each.

[0081] 2. After ultrasonic cleaning in step 1, the stainless steel substrate is immersed in a 3 mol / L dilute hydrochloric acid solution under heat. -1 The acid leaching time was 4 hours and the acid leaching temperature was 60 ℃.

[0082] 3. After the acid leaching in step 2 is completed, the stainless steel substrate is rinsed with deionized water and dried to obtain a clean stainless steel substrate.

[0083] 4. Dissolve 3.0448 g thiourea, 5.8158 g nickel nitrate hexahydrate and 8.0799 g ferric nitrate nonahydrate in 20 ml of deionized water and mix well.

[0084] 5. Place the solution prepared in step 4 at room temperature and stir for 80 minutes to ensure it is thoroughly mixed.

[0085] 6. Then, the clean stainless steel substrate obtained in step 3 is placed into the solution stirred in step 5 and heated to react; the reaction temperature is 90 °C and the reaction time is 24 h.

[0086] 7. After the reaction in step 6 is completed, the sample is washed with water and dried at 60 °C for 2 h to obtain the square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode.

[0087] Example 5

[0088] 1. Clean the stainless steel substrate sequentially with deionized water, acetone, and ethanol using ultrasonic cleaning for 10 minutes each.

[0089] 2. After ultrasonic cleaning in step 1, the stainless steel substrate is immersed in a 3 mol / L dilute hydrochloric acid solution under heat. -1 The acid leaching time was 4 hours and the acid leaching temperature was 60 ℃.

[0090] 3. After the acid leaching in step 2 is completed, the stainless steel substrate is rinsed with deionized water and dried to obtain a clean stainless steel substrate.

[0091] 4. Dissolve 3.0448 g thiourea, 5.8158 g nickel nitrate hexahydrate and 2.6933 g ferric nitrate nonahydrate in 20 ml of deionized water and mix well.

[0092] 5. Place the solution prepared in step 4 at room temperature and stir for 80 minutes to ensure it is thoroughly mixed.

[0093] 6. Then, the clean stainless steel substrate obtained in step 3 is placed into the solution stirred in step 5 and heated to react; the reaction temperature is 90 °C and the reaction time is 24 h.

[0094] 7. After the reaction in step 6 is completed, the sample is washed with water and dried at 60 °C for 2 h to obtain the square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode.

[0095] Results and Discussion: In Examples 1, 4, and 5, under the same conditions (ratio of two metal cations, amount of water, and reaction in a 90 °C oven for 24 h), the ratio of sulfur to metal cations in the solution was adjusted by changing the amount of sulfur and metal salt added.

[0096] Application Example 1

[0097] The square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode obtained in Examples 1-3 was used as the integrated electrode for the oxidation reaction of the electrocatalytic water splitting oxygen production system. The effect of gradually changing the ratio of the two metal cations in the solution on the catalytic performance of the square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrode was investigated.

[0098] 1. Test system setup: The test device is a three-electrode system. The reference electrode is Hg / HgO (1M KOH solution), the counter electrode is a C rod, the working electrode is a 1*1 cm stainless steel surface-modified bimetallic sulfide integrated electrode, and the electrolyte is 1M KOH solution.

[0099] 2. Catalytic performance evaluation method: The electrolytic cell temperature was maintained at 25 ℃. The ability of the catalyst to oxidize hydroxide anions (-OH) in the solution was tested by polarization curve, and the potential required by the catalyst to reach a certain oxidation current density was compared.

[0100] 3. The catalytic performance of the integrated electrode changes when the ratio of the two transition metal cations in the solution is gradually altered. For example... Figure 6 As shown, the stainless steel surface-modified metal sulfide integrated electrode (S-1) in Example 1 exhibits the best catalytic performance compared to Examples 2 (S-2) and 3 (S-3). At the same current density (100 mA cm⁻¹), -2 The overpotential of Example 1 (S-1) was 414 mV, that of Example 2 (S-2) was 444 mV, and that of Example 3 (S-3) was 508 mV. Therefore, by adjusting the ratio of the two metal cations in the solution, the catalytic activity of the catalyst in the electrocatalytic water splitting and oxygen evolution reaction can be adjusted, thereby finding the optimal ratio.

[0101] Application Example 2

[0102] The square meter-scale stainless steel surface-modified bimetallic sulfide integrated electrodes obtained in Examples 1, 4 and 5 were used as integrated electrodes for the oxidation reaction of the electrocatalytic water splitting oxygen production system. The effect of gradually changing the ratio of sulfur and metal cations in the solution on the catalytic performance of the stainless steel surface-modified bimetallic sulfide integrated electrodes was investigated.

[0103] 1. Test system setup: The test device is a three-electrode system. The reference electrode is Hg / HgO (1M KOH solution), the counter electrode is a C rod, the working electrode is a 1*1 cm stainless steel surface-modified bimetallic sulfide integrated electrode, and the electrolyte is 1 M KOH solution.

[0104] 2. Catalytic performance evaluation method: The electrolytic cell temperature was maintained at 25℃, and the concentration of hydroxide ions (OH-) in the catalyst oxidation solution was tested using polarization curves. - The ability of the catalyst to achieve a certain oxidation current density is compared to the potential required by the catalyst.

[0105] 3. The catalytic performance of the integrated electrode changes by gradually altering the ratio of sulfur to transition metal cations in the solution. For example... Figure 7As shown, the stainless steel surface-modified metal sulfide integrated electrode (S-1) in Example 1 exhibits the best catalytic performance compared to Examples 4 (S-4) and 5 (S-5). At the same current density (100 mA / cm²), -2 The overpotential of Example 1 (S-1) was 414 mV, that of Example 4 (S-4) was 593 mV, and that of Example 5 (S-5) was 441 mV. Therefore, by adjusting the ratio of sulfur to metal cations in the solution, the catalytic activity of the catalyst in the electrocatalytic water splitting and oxygen evolution reaction can be adjusted, thereby finding the optimal ratio.

[0106] 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A square meter level stainless steel surface modified bi-metallic sulphidic monolithic electrode characterized by: The application relates to a microsphere structure wrapped by super-thin nanosheets, wherein the super-thin nanosheets are nickel-iron sulfide, the microspheres are sulfur elemental substance, and the super-thin nanosheet-wrapped sulfur elemental microsphere material is uniformly distributed on a stainless steel surface. The thickness of the super-thin nanosheets is 5-50 nm, and the diameter of the microspheres is 5-50 mu m.

2. The square meter level stainless steel surface modified bi-metallic vulcanized monolithic electrode according to claim 1, characterized in that: The preparation is implemented by using a one-step hydrothermal method.

3. A method for preparing a square meter level stainless steel surface modified bi-metallic sulfidic monolithic electrode according to any one of claims 1-2, characterized by The application relates to a method for preparing a square-meter-level stainless steel surface modified bimetallic sulfide integrated electrode. (1) a stainless steel substrate is sequentially cleaned by ultrasonic cleaning with deionized water, acetone and ethanol, heated and soaked in a dilute hydrochloric acid solution, and finally cleaned by rinsing with deionized water and dried to obtain a clean stainless steel substrate; (2) two kinds of transition metal cation salts and a sulfur source are dissolved in an aqueous solution, and the mixture is stirred at room temperature until it is uniformly mixed; (3) the clean stainless steel substrate obtained in step (1) is placed in the solution in step (2) for heating reaction, and after the reaction is completed, the obtained sample is washed with water and dried to obtain the square-meter-level stainless steel surface modified bimetallic sulfide integrated electrode.

4. The method of claim 3, wherein: The ultrasonic cleaning time in the step (1) is 5-20 min; the dilute hydrochloric acid concentration is 1-5 mol L -1 ; the acid dipping temperature is 50-80 ℃, and the acid dipping time is 1-8 h.

5. The method of claim 3, wherein: In step (2), the transition metal cation salt is at least one of a nitrate salt, a sulfate salt or a chloride salt of a transition metal cation; the metal cation is nickel and iron; the sulfur source is at least one of thiourea, thioacetamide, sodium sulfide and mercaptan; in the solution after the transition metal cation salt and the sulfur source are dissolved, the molar ratio of sulfur anions to transition metal cations is 1:5-5:1; and the molar ratio of the two kinds of transition metal cations is 1:4-4:

1.

6. The method of claim 3, wherein: In step (2), the stirring time at room temperature is 30-120 min.

7. The preparation method according to claim 3, characterized in that, In step (3), the reaction temperature is 60-100 DEG C, the reaction time is 12-24 h, the drying temperature is 30-100 DEG C, and the drying time is 1-6 h.

8. Application of the square-meter-level stainless steel surface modified bimetallic sulfide integrated electrode according to any one of claims 1-2 as an integrated electrode material in an electrocatalytic reaction.

9. Use according to claim 8, characterized in that: The electrocatalytic reaction is a hydrogen evolution reaction of electrolytic water.

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