Preparation of ternary metal sulfide film electrode and application of electrolysis of water to produce hydrogen

Abstract

The application belongs to the field of hydrogen production by water electrolysis, and discloses a preparation of a ternary metal sulfide membrane electrode and application of the ternary metal sulfide membrane electrode in hydrogen production by water electrolysis, and the preparation method comprises the following steps: (1) preparing a nickel mesh; (2) placing the nickel mesh into a mixed solvent in which metal salt and sulfur source are dissolved, and then stirring and performing a hydrothermal reaction; (3) collecting the hydrothermal product to obtain a ternary metal sulfide electrode; and (4) placing the ternary metal sulfide electrode as a cathode catalytic layer and an anode catalytic layer at the two sides of a solid electrolyte membrane to assemble a membrane electrode. The preparation method of the electrode is improved, the nickel mesh is used as a substrate, the ternary metal sulfide is in-situ grown on the nickel mesh substrate by a one-step hydrothermal method to form a ternary metal sulfide electrode, and the corresponding membrane electrode can be directly used in an alkaline electrolytic cell for hydrogen production. The electrolytic cell has excellent catalytic activity and stability under an amperometric current density, and is expected to be applied to industrial water electrolysis for hydrogen production.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen production by water electrolysis, and more specifically, relates to the preparation of a ternary metal sulfide membrane electrode and its application in hydrogen production by water electrolysis. Background Technology

[0002] Electrolysis of water is one of the effective methods for obtaining renewable and clean hydrogen energy. Alkaline water electrolysis (AWE) technology, as a clean and environmentally friendly hydrogen production technology, offers advantages over traditional alkaline water electrolysis technology. The membrane electrolyzer in AWE technology has a smaller volume (e.g., 9 cm³). 2 High current density (e.g., 400 mA cm⁻¹) can be achieved at this level. -2 Then, it efficiently produces high-purity hydrogen. Therefore, the membrane electrolyzer provides a reliable and clean hydrogen production route, truly achieving zero-carbon emission hydrogen production.

[0003] Membrane electrode assembly (MEA) is a key component in membrane electrolyzers. Currently, improvements in water electrolysis efficiency are limited by the slow kinetics of the oxygen evolution reaction (OER). The development of noble metal-based electrode materials (IrO2 or RuO2) is constrained by their low availability and cost-effectiveness. Therefore, there is an urgent need to develop high-performance non-noble metal electrodes. Existing technologies know that transition metal-based electrode materials (transition metal sulfides, nitrides, etc.) have advantages such as abundant reserves and high electrochemical performance. Among them, multi-metal-based electrode materials, due to the synergistic effect between multiple metal atoms and the tunable electronic structure, can effectively reduce the reaction energy barrier and achieve high current density output at low overpotentials. However, existing materials often exhibit current densities in the milliampere range (e.g., 10–100 mA cm⁻¹). -2 The activity and stability at the specified current density did not reach the ampere level (ampere level current density, i.e., current density ≥ 1 A cm⁻¹). -2 If an ampere-level current density can be obtained (i.e., current density ≥ 1 Acm), -2 Electrodes with high activity and high stability will undoubtedly be more beneficial for industrial applications. Summary of the Invention

[0004] To address the aforementioned deficiencies or improvement needs of existing technologies, the present invention aims to provide a method for preparing a ternary metal sulfide membrane electrode and its application in water electrolysis for hydrogen production. This method improves the electrode preparation method by using a nickel mesh as a substrate. A ternary metal sulfide electrode is formed by in-situ growth of ternary metal sulfides onto the nickel mesh substrate using a one-step hydrothermal method. The ternary metal sulfide electrode is then assembled with a solid electrolyte membrane, simultaneously serving as both the anode and cathode catalytic layers, to form a membrane electrode. The resulting membrane electrode can be directly used in an alkaline electrolyzer for hydrogen production. This electrolyzer operates at ampere-level current densities (i.e., current density ≥ 1 A cm⁻¹). -2This membrane electrode exhibits excellent catalytic activity and stability, and is expected to be applied to industrial water electrolysis for hydrogen production; furthermore, it is particularly suitable for alkaline electrolyzers using strong alkaline electrolytes. In addition, the preparation method of this invention has the advantages of simple operation and high cost-effectiveness.

[0005] To achieve the above objectives, according to one aspect of the present invention, a method for preparing a ternary metal sulfide film electrode is provided, characterized by comprising the following steps:

[0006] (1) Prepare a nickel mesh and pre-treat the nickel mesh to remove surface impurities;

[0007] (2) The nickel mesh is placed in a mixed solvent containing a metal salt and a sulfur source, stirred, and then transferred to a reaction vessel for hydrothermal reaction to obtain a hydrothermal product; wherein the metal salt is a mixture of nickel salt, iron salt and molybdenum salt; the mixed solvent is a mixture of ethylene glycol and deionized water; the hydrothermal product is a ternary metal sulfide grown in situ on the nickel mesh, and the ternary metal elements in the ternary metal sulfide are nickel, iron and molybdenum.

[0008] (3) Collect the hydrothermal products, and after cleaning and drying, a ternary metal sulfide electrode can be obtained;

[0009] (4) The ternary metal sulfide electrode is placed on both sides of the solid electrolyte membrane as both the cathode catalytic layer and the anode catalytic layer to assemble the membrane electrode.

[0010] As a further preferred embodiment of the present invention, in step (2), the sulfur source is thiourea; the molar ratio of the nickel salt, iron salt and molybdenum salt in the metal salt is 1:1:1:-4:3:20; the concentration of the metal salt in the mixed solvent is 0.03-0.3 mol / L; and the molar ratio of the sulfur source to the molybdenum salt is 1:4-5:2.

[0011] Preferably, the nickel salt is nickel nitrate or nickel chloride; the iron salt is ferric nitrate or ferric chloride; and the molybdenum salt is ammonium molybdate.

[0012] As a further preferred embodiment of the present invention, in step (2), the hydrothermal temperature of the hydrothermal reaction is 140-180℃, and the heat preservation time is 8-12 h;

[0013] The preferred mixed solvent is a mixture of ethylene glycol and deionized water in a volume ratio of 2:1 to 5:1.

[0014] As a further preferred embodiment of the present invention, in step (1), the wire diameter of the nickel mesh is in the range of 0.15-0.35 mm, and the mesh size of the nickel mesh is in the range of 0.1-0.48 mm;

[0015] The pretreatment specifically involves immersing the nickel mesh sequentially in hydrochloric acid solution, anhydrous ethanol, and deionized water for ultrasonic cleaning, followed by drying.

[0016] As a further preferred embodiment of the present invention, in step (4), the solid electrolyte membrane is selected from anion exchange membranes and proton exchange membranes.

[0017] As a further preferred embodiment of the present invention, in step (3), the cleaning specifically involves immersing the hydrothermal product in anhydrous ethanol and deionized water in sequence for ultrasonic cleaning.

[0018] According to another aspect of the present invention, the present invention provides a ternary metal sulfide film electrode prepared by the above-described preparation method.

[0019] According to another aspect of the present invention, the present invention provides the application of the above-mentioned ternary metal sulfide membrane electrode as a catalytic electrode in hydrogen production in an alkaline electrolyzer.

[0020] As a further preferred embodiment of the present invention, the electrolyte used in the alkaline electrolytic cell for hydrogen production is a strong alkaline electrolyte, preferably a KOH solution with a concentration of 1-7.6 mol / L, and more preferably a KOH solution with a concentration of 7.6 mol / L;

[0021] The alkaline electrolytic cell operates at a current density ≥ 1 A cm⁻¹ -2 .

[0022] According to another aspect of the present invention, the present invention provides an alkaline electrolytic cell, characterized in that the above-mentioned ternary metal sulfide membrane electrode is used as a catalytic electrode.

[0023] Compared with the prior art, the present invention uses a nickel mesh as a substrate to prepare a ternary metal sulfide electrode via a one-step hydrothermal method, and uses it simultaneously as both a cathode and anode catalyst, assembling it with a solid electrolyte membrane to obtain a membrane electrode. Similar to transition metal-based electrode materials in the prior art, the membrane electrode obtained by the present invention has a high active specific surface area and a multi-metal structure. More importantly, the membrane electrode obtained by the present invention exhibits high performance at ampere-level current densities (i.e., current density ≥ 1 A cm⁻¹). -2 It exhibits high activity and stability under strong alkaline electrolyte conditions, and is particularly suitable for alkaline electrolyzers with strong alkaline electrolytes, such as electrocatalytic oxygen evolution under industrial alkaline water electrolysis conditions (e.g., 7.6 M KOH). The resulting alkaline electrolyzer can effectively solve the technical problems of poor electrode activity and stability at ampere-level current densities in the current field of hydrogen production by water electrolysis.

[0024] Many existing technologies also use nickel foam as a substrate to form transition metal-based electrode materials, which achieve current densities in the milliampere range (e.g., 10–100 mA cm⁻¹). -2 While exhibiting good activity and stability at ampere-level current densities, its stability is not clear at ampere-level current densities. This invention utilizes a nickel mesh (with wire diameters particularly in the range of 0.15-0.35 mm and mesh openings particularly in the range of 0.1-0.48 mm; for example, the nickel mesh with an opening diameter of 0.1 mm and a wire diameter of 0.15 mm used in the later embodiments) as a substrate to prepare a ternary metal sulfide electrode using a one-step hydrothermal method. This electrode exhibits high activity and high stability at ampere-level current densities. The resulting alkaline electrolyzer is particularly suitable for industrial alkaline water electrolysis conditions (e.g., 7.6 M KOH) for hydrogen production.

[0025] Specifically, the present invention can achieve the following beneficial effects:

[0026] (1) This invention uses nickel mesh and metal salts as raw materials to prepare a ternary metal sulfide electrode via a one-step hydrothermal method. This results in a heterogeneous interface between crystalline and amorphous phases, unlike ordinary self-supporting electrodes, thus exhibiting a unique synergistic effect. This approach increases the specific surface area of ​​the self-supporting electrode and promotes the exposure of active sites. When used as an electrocatalytic oxygen evolution electrode under industrial alkaline water electrolysis conditions (7.6 M KOH), the ternary metal sulfide electrode demonstrates excellent oxygen evolution activity and high current stability (1 A cm⁻¹). -2 It can work stably for 120 hours.

[0027] (2) The self-supporting electrode based on in-situ growth of nickel mesh in this invention can be directly assembled with a solid electrolyte membrane and used as a membrane electrode in an alkaline electrolyzer. This improvement not only avoids the use of binders but also greatly enhances the electrochemical activity and stability of the catalyst. Taking powdered catalysts in the prior art as an example, powdered catalysts often need to be mixed with binders such as Nafion, ultrasonically coated, and then sprayed onto a conductive substrate. Such powdered catalysts are used at high current densities (e.g., 400 mA cm⁻¹). -2 It is prone to powder shedding and has poor stability, especially at ampere-level current densities (such as 1 A cm⁻¹). -2 Furthermore, the method of this invention yields a self-supporting catalyst grown in situ on a conductive substrate, which can be directly used in electrochemical reactions without the need for a binder. Attached Figure Description

[0028] Figure 1 The image in the middle is the XRD pattern of the ultrasonic powder of the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1.

[0029] Figure 2(a) and (b) are scanning electron microscope (SEM) images of the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 at different magnifications.

[0030] Figure 3 This is a transmission electron microscope (TEM) image of the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1.

[0031] Figure 4 Linear voltammetric curves of the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 and two different electrodes in Comparative Example 1 at 1 M KOH.

[0032] Figure 5 The chronocurrent curve of the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 at 1 M KOH.

[0033] Figure 6 Linear voltammetric curves of the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 and two different electrodes in Comparative Example 1 at 7.6 M KOH.

[0034] Figure 7 Chronocurrent curves of the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 at 7.6 M KOH.

[0035] Figure 8 This is a simplified diagram of a membrane electrode used in alkaline electrolyzers for hydrogen production.

[0036] Figure 9 The diagram shows the electrolysis performance of the membrane electrode (NiFeMoS / NM || NiFeMoS / NM) prepared in Example 1 and two different membrane electrodes in Comparative Example 1 at 7.6 M KOH.

[0037] Figure 10 The chronovoltage curve of the membrane electrode (NiFeMoS / NM || NiFeMoS / NM) prepared in Example 1 at 7.6 M KOH; the voltage waveform shown in the figure corresponds to a current density of 2 A cm⁻¹ at the peak voltage. -2 The current density corresponding to the trough voltage is 1 A cm⁻¹ -2 . Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0039] Example 1

[0040] This embodiment provides a method for preparing a ternary metal sulfide film electrode, the method comprising:

[0041] (1) Cut nickel mesh to a certain size (3*3 cm) 2 The material used is a 100-mesh thickened nickel mesh from Hebei Chaochuang Metal Mesh Co., Ltd. (the mesh aperture is 0.1 mm and the wire diameter is 0.15 mm). The mesh is then subjected to ultrasonic treatment in hydrochloric acid (0.1 M), anhydrous ethanol, and deionized water to remove impurities (such as oxides on the surface). Each ultrasonic treatment lasts for 20 minutes. The mesh is then dried in a vacuum oven at 60 ℃ for 12 hours.

[0042] (2) Weigh 0.365 g nickel nitrate, 0.243 g ferric chloride, 1.976 g ammonium molybdate and 0.2 g thiourea and dissolve them in a mixture of 40 mL ethylene glycol and 10 mL deionized water and stir to form solution A.

[0043] (3) Immerse the nickel mesh from step (1) into solution A obtained in step (2), stir at room temperature, and then transfer it to a reaction vessel. Place the reaction vessel in a high-temperature oven and react at 140 °C for 10 h, then allow it to cool naturally to room temperature. Collect the hydrothermal product, clean it, and dry it in a vacuum oven to obtain the ternary metal sulfide electrode (NiFeMoS / NM).

[0044] (4) Using NiFeMoS / NM electrodes as both the cathode and anode catalyst layers, and assembling them on both sides of the anion exchange membrane, a membrane electrode is obtained (e.g., Figure 8 As shown, the membrane electrodes from left to right are: a nickel mesh and a ternary metal sulfide grown in situ on the nickel mesh, a solid electrolyte membrane, and a nickel mesh and a ternary metal sulfide grown in situ on the nickel mesh.

[0045] (5) Assemble the membrane electrode from step (4) with other components to form an alkaline electrolyzer (refer to the existing technology related to alkaline electrolyzers, and assemble the end plate, sealing gasket, electrode plate and other components with the membrane electrode to obtain an alkaline electrolyzer). Apply voltage to the electrolyzer at room temperature to 80°C and perform single cell testing.

[0046] Example 2

[0047] This embodiment provides a method for preparing a ternary metal sulfide film electrode, the method comprising:

[0048] (1) Cut nickel mesh to a certain size (3*3 cm) 2 The material used was a 100-mesh thickened nickel mesh from Hebei Chaochuang Metal Mesh Co., Ltd. It was then subjected to ultrasonic cleaning in hydrochloric acid (0.1 M), anhydrous ethanol, and deionized water, with each ultrasonic cleaning lasting 20 minutes. Finally, it was dried in a vacuum oven at 60 ℃ for 12 hours.

[0049] (2) Weigh 0.365 g nickel nitrate, 0.243 g ferric chloride, 1.976 g ammonium molybdate and 0.2 g thiourea and dissolve them in a mixture of 60 mL ethylene glycol and 10 mL deionized water and stir to form solution A.

[0050] (3) Immerse the nickel mesh from step (1) into solution A obtained in step (2), stir at room temperature, and then transfer it to a reaction vessel. Place the reaction vessel in a high-temperature oven and react at 140 °C for 10 h, then allow it to cool naturally to room temperature. Collect the hydrothermal product, clean it, and dry it in a vacuum oven to obtain the ternary metal sulfide electrode (NiFeMoS / NM).

[0051] (4) Using NiFeMoS / NM electrodes as both cathode and anode catalyst layers, and assembling them on both sides of the anion exchange membrane, a membrane electrode is obtained.

[0052] (5) Assemble the membrane electrode from step (4) with other components into an alkaline electrolytic cell, apply voltage to the electrolytic cell at room temperature to 80°C, and perform single cell testing.

[0053] Example 3

[0054] This embodiment provides a method for preparing a ternary metal sulfide film electrode, the method comprising:

[0055] (1) Cut nickel mesh to a certain size (3*3 cm) 2 The material used was a 100-mesh thickened nickel mesh from Hebei Chaochuang Metal Mesh Co., Ltd. It was then subjected to ultrasonic cleaning in hydrochloric acid (0.1 M), anhydrous ethanol, and deionized water, with each ultrasonic cleaning lasting 20 minutes. Finally, it was dried in a vacuum oven at 60 ℃ for 12 hours.

[0056] (2) Weigh 0.1827 g nickel nitrate, 0.162 g ferric chloride, 0.1976 g ammonium molybdate and 0.1 g thiourea and dissolve them in a mixture of 40 mL ethylene glycol and 10 mL deionized water and stir to form solution A.

[0057] (3) Immerse the nickel mesh from step (1) into solution A obtained in step (2), stir at room temperature, and then transfer it to a reaction vessel. Place the reaction vessel in a high-temperature oven and react at 160 °C for 10 h, then allow it to cool naturally to room temperature. Collect the hydrothermal product, clean it, and dry it in a vacuum oven to obtain the ternary metal sulfide electrode (NiFeMoS / NM).

[0058] (4) Using NiFeMoS / NM electrodes as both cathode and anode catalyst layers, and assembling them on both sides of the anion exchange membrane, a membrane electrode is obtained.

[0059] (5) Assemble the membrane electrode from step (4) with other components into an alkaline electrolytic cell, apply voltage to the electrolytic cell at room temperature to 80°C, and perform single cell testing.

[0060] Comparative Example 1

[0061] First, cut a nickel mesh to a certain size (3*3 cm). 2 The nickel mesh used was a 100-mesh thickened nickel mesh from Hebei Chaochuang Metal Mesh Co., Ltd., which was then subjected to ultrasonic treatment in hydrochloric acid (0.1 M), anhydrous ethanol and deionized water in sequence. Each ultrasonic treatment lasted for 20 min. Afterwards, it was dried in a vacuum oven at 60 ℃ for 12 h to obtain the nickel mesh (NW) as a control sample.

[0062] Application Example 1

[0063] The ternary metal sulfide electrode (NiFeMoS / NM) obtained in step (3) of Example 1 and the nickel mesh (NW) obtained in Comparative Example 1 were used as industrial oxygen evolution (OER) electrodes, and the activity of the electrodes was evaluated.

[0064] Electrochemical performance was tested using a three-electrode system at room temperature. The specific steps are as follows: A ternary metal sulfide electrode (NiFeMoS / NM 1*1 cm) obtained in Example 1 was cut. 2 Using this as the working electrode, a carbon rod as the counter electrode, and a self-made reversible hydrogen electrode as the reference electrode, the electrode was first scanned 50 times in an oxygen-saturated 1 M KOH solution from an initial potential of 1 V to 2 V (relative to the reversible hydrogen electrode) at a scan rate of 50 mV / s to activate the catalyst. Subsequently, in an oxygen-saturated 1 M KOH solution, the linear sweep voltammetry curve of the self-supported electrode (NiFeMoS / NM) was obtained by scanning from 1 to 1.9 V at a rate of 10 mV / s. The linear sweep voltammetry curve of the electrode obtained in Example 1 corresponds to... Figure 4 The middle dashed line.

[0065] Application Example 2

[0066] The ternary metal sulfide electrode (NiFeMoS / NM) obtained in step (3) of Example 1 and the nickel mesh (NW) obtained in Comparative Example 1 were used as industrial oxygen evolution (OER) electrodes for water electrolysis, and the activity of the catalysts was evaluated.

[0067] Electrochemical performance was tested using a three-electrode system at room temperature. The specific steps are as follows: A ternary metal sulfide electrode (NiFeMoS / NM 1*1 cm) obtained in Example 1 was cut. 2 Using this as the working electrode, a carbon rod as the counter electrode, and a self-made reversible hydrogen electrode as the reference electrode, the electrode was first scanned 50 times in an oxygen-saturated 7.6 M KOH solution from an initial potential of 1 V to 2 V (relative to the reversible hydrogen electrode) at a scan rate of 50 mV / s to activate the catalyst. Subsequently, in an oxygen-saturated 7.6 M KOH solution, the linear sweep voltammetry curve of the self-supported electrode (NiFeMoS / NM) was obtained by scanning from 1 to 1.9 V at a rate of 10 mV / s. The linear sweep voltammetry curve of the electrode obtained in Example 1 corresponds to... Figure 6 The middle dashed line.

[0068] Application Example 3

[0069] The ternary metal sulfide electrode (NiFeMoS / NM) obtained in step (3) of Example 1 and the nickel mesh (NW) obtained in Comparative Example 1 were used simultaneously as an anode / cathode and an anion exchange membrane to assemble a membrane electrode (see schematic diagram of the membrane electrode structure). Figure 8 (As shown), it was used in an alkaline electrolyzer, and the activity of the catalyst was evaluated.

[0070] The battery was tested using a two-electrode system at room temperature (RT) and 80°C, respectively. The specific implementation steps are as follows: The ternary metal sulfide electrode (NiFeMoS / NM 3*3 cm) obtained in Example 1 was used. 2 Simultaneously serving as both the anode and cathode catalytic layers, the solid electrolyte water electrolysis membrane electrode structure is formed by stacking the anode substrate, anode catalytic layer, anion exchange membrane, cathode catalytic layer, and cathode substrate layer in sequence. Adding an external metal plate yields a single cell.

[0071] The fabricated single cells were tested using a FETS-100 cell testing system at room temperature and 80°C, without external pressure. A voltage was applied to the cells for single-cell testing.

[0072] Results Analysis

[0073] The ternary metal sulfide electrodes prepared in the above embodiments were characterized in terms of morphology and electrochemical performance by scanning electron microscopy, electrochemical testing in a three-electrode system, and battery performance in an alkaline electrolyzer.

[0074] from Figure 2 As can be seen from (a) and (b), the morphology of the active metal material on the ternary metal sulfide electrode prepared in Example 1 of the present invention is mainly granular, and the granular active material (NiFeMoS) grows uniformly on the surface of the nickel mesh (NM).

[0075] from Figure 3 It can be seen that NiFeMoS nanoparticles have abundant heterogeneous interfaces between crystalline and amorphous phases. The synergistic effect of the crystalline and amorphous phases can regulate the electronic structure of the catalytic material and expose more active sites.

[0076] from Figure 4 It can be seen that in an alkaline electrolyte (1 M KOH), the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 of this invention can reach 500 mA / cm at a relatively low potential. 2 This indicates that the prepared ternary metal sulfide electrode has high electrochemical oxygen evolution activity in industrial water electrolysis systems.

[0077] from Figure 5 It can be seen that in an alkaline electrolyte (1 M KOH), the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 of this invention exhibits a performance of 1 A / cm². 2 It can operate stably for 120 hours and has high electrochemical stability under high current density.

[0078] from Figure 6 It can be seen that in an industrial alkaline electrolyte (7.6 M KOH), the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 of this invention exhibits a performance of 100 mA / cm². 2 When the reversible hydrogen electrode potential is less than that of Comparative Example 1, it indicates that the prepared ternary metal sulfide electrode has high electrochemical oxygen evolution activity in the industrial water electrolysis system.

[0079] from Figure 7 It can be seen that in an industrial alkaline electrolyte (7.6 M KOH), the ternary metal sulfide electrode (NiFeMoS / NM) prepared in Example 1 of this invention exhibits a performance of 1 A / cm². 2 It can operate stably for 120 hours and has high electrochemical stability under high current density.

[0080] from Figure 8 As can be seen, the alkaline electrolyzer prepared by the present invention is composed of membrane electrodes and other components.

[0081] from Figure 9It can be seen that in an industrial alkaline electrolyte (7.6 M KOH), the NiFeMoS / NM || NiFeMoS / NM alkaline electrolytic cell prepared in Example 1 of this invention can achieve 1 A cm⁻¹ electrolysis at 80°C with only 1.86 V. -2 The current density indicates that the prepared ternary metal sulfide electrode has high electrochemical activity in industrial water electrolysis systems.

[0082] from Figure 10 It can be seen that in an industrial alkaline electrolyte (7.6 M KOH), the NiFeMoS / NM || NiFeMoS / NM alkaline electrolytic cell prepared in Example 1 of this invention performs well at 2 A cm⁻¹. -2 It can still operate at 1 A cm after working at current density -2 Stable operation at current density indicates that NiFeMoS / NM has high electrochemical stability at ampere-level current densities.

[0083] In addition to the above, Figure 9 Except for the temperature, all other figures were obtained at room temperature.

[0084] The above embodiments are merely examples; in addition to the above embodiments, using different nickel meshes, that is, using other nickel meshes from Hebei Chaochuang Metal Mesh Co., Ltd. with a mesh size of 30 to 100 (correspondingly, the wire diameter of the nickel mesh is in the range of 0.15-0.35 mm, and the mesh size of the nickel mesh is in the range of 0.1-0.48 mm), can also achieve similar results (of course, Embodiment 1 has the best effect).

[0085] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a ternary metal sulfide film electrode with high activity and high stability at ampere-level current densities, characterized in that, Includes the following steps: (1) Prepare a nickel mesh and pre-treat the nickel mesh to remove surface impurities; the wire diameter of the nickel mesh is in the range of 0.15-0.35 mm and the mesh size is in the range of 0.1-0.48 mm. (2) The nickel mesh is placed in a mixed solvent containing a metal salt and a sulfur source, stirred, and then transferred to a reaction vessel for hydrothermal reaction to obtain a hydrothermal product; wherein the metal salt is a mixture of nickel salt, iron salt and molybdenum salt; the mixed solvent is a mixture of ethylene glycol and deionized water; the hydrothermal product is a ternary metal sulfide grown in situ on the nickel mesh, and the ternary metal elements in the ternary metal sulfide are nickel, iron and molybdenum. (3) Collect the hydrothermal products, and after cleaning and drying, a ternary metal sulfide electrode can be obtained; (4) The ternary metal sulfide electrode is placed on both sides of the solid electrolyte membrane as both the cathode catalytic layer and the anode catalytic layer to assemble a membrane electrode; the membrane electrode has high activity and high stability at an ampere-level current density, wherein the ampere-level current density is ≥1 A cm⁻¹. -2 .

2. The preparation method according to claim 1, characterized in that, In step (2), the sulfur source is thiourea; the molar ratio of the nickel salt, iron salt and molybdenum salt in the metal salt is 1:1:1:-4:3:20; the concentration of the metal salt in the mixed solvent is 0.03-0.3 mol / L; and the molar ratio of the sulfur source to the molybdenum salt is 1:4-5:

2.

3. The preparation method according to claim 2, characterized in that, In step (2), the nickel salt is nickel nitrate or nickel chloride; the iron salt is ferric nitrate or ferric chloride; and the molybdenum salt is ammonium molybdate.

4. The preparation method according to claim 1, characterized in that, In step (2), the hydrothermal temperature of the hydrothermal reaction is 140-180℃, and the heat preservation time is 8-12 h.

5. The preparation method according to claim 4, characterized in that, In step (2), the mixed solvent is a mixture of ethylene glycol and deionized water in a volume ratio of 2:1 to 5:

1.

6. The preparation method according to claim 1, characterized in that, In step (1), the pretreatment specifically involves immersing the nickel mesh sequentially in hydrochloric acid solution, anhydrous ethanol, and deionized water for ultrasonic cleaning, followed by drying.

7. The preparation method according to claim 1, characterized in that, In step (4), the solid electrolyte membrane is selected from anion exchange membranes and proton exchange membranes.

8. The preparation method according to claim 1, characterized in that, In step (3), the cleaning specifically involves immersing the hydrothermal product in anhydrous ethanol and deionized water for ultrasonic cleaning.

9. A ternary metal sulfide film electrode prepared by the preparation method according to any one of claims 1-8.

10. The application of the ternary metal sulfide membrane electrode as described in claim 9 as a catalytic electrode in hydrogen production in an alkaline electrolyzer.

11. The application as described in claim 10, characterized in that, The electrolyte used in the alkaline electrolyzer for hydrogen production is a strong alkaline electrolyte. The alkaline electrolytic cell operates at a current density ≥ 1 A cm⁻¹ -2 .

12. The application as described in claim 11, characterized in that, The strong alkaline electrolyte is a KOH solution with a concentration of 1-7.6 mol / L.

13. The application as described in claim 11, characterized in that, The strong base electrolyte is a KOH solution with a concentration of 7.6 mol / L.

14. An alkaline electrolytic cell, characterized in that, The ternary metal sulfide membrane electrode as described in claim 9 is used as the catalytic electrode.

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