High-entropy alloy electrode material and preparation method and application thereof

Abstract

The application provides a high-entropy alloy electrode material and a preparation method and application thereof, wherein the preparation method comprises the following steps: S1, taking nickel salt, copper salt, iron salt, molybdenum salt and tungsten salt as raw materials, mixing the raw materials with an aqueous solution of ammonium sulfate, sodium dodecyl sulfonate and sodium citrate to obtain an electroplating solution; S2, performing electrodeposition treatment on a pretreated nickel substrate in the electroplating solution, and then performing water washing and drying treatment in sequence to obtain the high-entropy alloy electrode material. The high-entropy alloy electrode material has relatively high catalytic activity, can improve the reaction efficiency and reduce energy consumption when applied to the water electrolysis process, and the preparation method is simple, low in cost, high in safety, suitable for large-scale production and wide in industrial application prospect.

Description

Technical Field

[0001] This application relates to the field of water electrolysis for hydrogen production technology, and in particular to a high-entropy alloy electrode material, its preparation method, and its application. Background Technology

[0002] Today, facing the dual challenges of the global energy crisis and environmental pollution, developing efficient and low-cost water electrolysis hydrogen production technology is particularly important. Traditional water electrolysis technology is limited by its high energy consumption and low efficiency, with high overpotentials leading to increased energy consumption. To overcome this challenge, researchers have been exploring novel electrode materials to improve the reaction efficiency of water electrolysis and reduce costs.

[0003] Electrodeposition is a technique for preparing high-entropy alloys in aqueous solutions using electrochemical methods. It has attracted attention due to its advantages such as simple operation, high cost-effectiveness, and high safety. In the field of alkaline water electrolysis for hydrogen production, high-entropy alloy electrodes prepared by electrodeposition exhibit excellent electrocatalytic activity and stability, thus facilitating large-scale production and industrial applications. However, existing high-entropy alloy materials suffer from cumbersome preparation methods, or their electrochemical performance during application needs further improvement.

[0004] Therefore, given the technical problems of cumbersome preparation methods and poor electrochemical performance of existing high-entropy alloy materials, there is an urgent need to provide a high-entropy alloy electrode material and its preparation method to improve these problems. Summary of the Invention

[0005] The main objective of this invention is to provide a high-entropy alloy electrode material, its preparation method, and its application, in order to solve the technical problems of cumbersome preparation methods or poor electrochemical performance of existing high-entropy alloy materials during application.

[0006] To achieve the above objectives, according to one aspect of the present invention, a method for preparing a high-entropy alloy electrode material is provided, comprising: step S1, taking nickel salt, copper salt, iron salt, molybdenum salt and tungsten salt as raw materials, mixing them with an aqueous solution of ammonium sulfate, sodium dodecyl sulfonate and sodium citrate to obtain an electroplating solution; step S2, subjecting a pretreated nickel substrate to electrodeposition treatment in the electroplating solution, followed by sequential water washing and drying treatment to obtain a high-entropy alloy electrode material.

[0007] Further, in step S1, the nickel salt is selected from one or more of nickel sulfate hexahydrate, nickel chloride hexahydrate, or nickel nitrate hexahydrate; preferably, the copper salt is selected from one or more of copper sulfate hexahydrate, copper chloride dihydrate, or copper nitrate trihydrate; preferably, the iron salt is selected from one or more of ferric sulfate heptahydrate, ferric nitrate nonahydrate, or ferric chloride hexahydrate; preferably, the molybdenum salt is selected from one or more of sodium molybdate dihydrate, ammonium molybdate tetrahydrate, or ammonium heptamolybdate tetrahydrate; preferably, the tungsten salt is selected from one or more of sodium tungstate dihydrate, ammonium tungstate decahydrate, or ammonium paratungstate.

[0008] Furthermore, in step S2, the electrodeposition treatment temperature is 25–50°C, the time is 10–30 min, and the current density is 0.05–0.2 A / cm². 2 .

[0009] Furthermore, the molar ratio of nickel salt, copper salt, iron salt, molybdenum salt and tungsten salt is (8-12):(3.1-5):(0.8-2.5):(0.6-3):1.

[0010] Further, in step S1, the weight ratio of ammonium sulfate, sodium dodecyl sulfonate and sodium citrate is (0.0001~0.002):(0.0001~0.003):1.

[0011] Further, in step S2, the pretreated nickel substrate includes: taking nickel mesh and / or foamed nickel and performing chemical degreasing and pickling treatments in sequence to obtain the pretreated nickel substrate.

[0012] Further, step S1 includes: taking nickel salt, copper salt, iron salt, molybdenum salt and tungsten salt as raw materials, mixing them with an aqueous solution of ammonium sulfate, sodium dodecyl sulfonate and sodium citrate, and then adjusting the pH value to 3.5-6.0 with sulfuric acid to obtain an electroplating solution.

[0013] To achieve the above objectives, according to one aspect of the present invention, a high-entropy alloy electrode material is provided, which is obtained by the preparation method of the above-mentioned high-entropy alloy electrode material, and the high-entropy alloy electrode material is a Ni-Cu-Fe-Mo-W high-entropy alloy.

[0014] According to another aspect of the present invention, an application of a high-entropy alloy electrode material is provided, which is used in the field of water electrolysis for hydrogen production.

[0015] Furthermore, high-entropy alloy electrode materials are used as catalysts for oxygen evolution cathodes and / or hydrogen evolution anodes in water electrolysis.

[0016] The high-entropy alloy electrode material prepared using the technical solution of this invention can not only improve reaction efficiency and reduce energy consumption, but also provides strong support for the commercialization and popularization of water electrolysis hydrogen production technology due to its low cost and high safety in the preparation process. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. In the drawings:

[0018] Figure 1 The image shows a SEM image (magnification 1000x) of the high-entropy alloy electrode material prepared according to Example 1 of the present invention; and

[0019] Figure 2 An elemental distribution diagram of the high-entropy alloy electrode material prepared according to Example 1 of the present invention is shown. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] As described in the background section of this invention, existing high-entropy alloy materials suffer from cumbersome preparation methods or poor electrochemical performance during application. Therefore, this invention provides a method for preparing a high-entropy alloy electrode material, comprising: step S1, using nickel salt, copper salt, iron salt, molybdenum salt, and tungsten salt as raw materials, mixing them with an aqueous solution of ammonium sulfate, sodium dodecyl sulfonate, and sodium citrate to obtain an electroplating solution; step S2, subjecting a pretreated nickel substrate to electrodeposition in the electroplating solution, followed by sequential water washing and drying to obtain the high-entropy alloy electrode material.

[0022] This invention utilizes high-entropy alloys, which are alloys composed of five or more elements in near-equiatomic ratios. The mixing of these elements can bring about a high-entropy effect. Due to the high-entropy effect and multi-element synergistic effect of high-entropy alloys, the adsorption energy of intermediates can be optimized, increasing the active sites and catalytic activity of the material, thereby improving the efficiency of water electrolysis (applications mentioned later). This invention provides a method for preparing high-entropy alloy electrode materials by electrochemical deposition, specifically including first preparing an electroplating solution, and then placing a nickel substrate in the electroplating solution for electrodeposition treatment to obtain the high-entropy alloy electrode material. This high-entropy alloy electrode material not only improves reaction efficiency and reduces energy consumption, but its low cost and high safety in preparation also provide strong support for the commercialization and popularization of water electrolysis hydrogen production technology.

[0023] In a preferred embodiment, in step S1, the nickel salt is selected from one or more of nickel sulfate hexahydrate, nickel chloride hexahydrate, or nickel nitrate hexahydrate; the copper salt is preferably selected from one or more of copper sulfate hexahydrate, copper chloride dihydrate, or copper nitrate trihydrate; the iron salt is preferably selected from one or more of ferric sulfate heptahydrate, ferric nitrate nonahydrate, or ferric chloride hexahydrate; the molybdenum salt is preferably selected from one or more of sodium molybdate dihydrate, ammonium molybdate tetrahydrate, or ammonium heptamolybdate tetrahydrate; and the tungsten salt is preferably selected from one or more of sodium tungstate dihydrate, ammonium tungstate decahydrate, or ammonium paratungstate. Thus, an electroplating solution containing the above five metal salt raw materials is prepared to prepare a high-entropy alloy electrode material with superior performance.

[0024] To further stabilize and complete the electrodeposition process, thereby enhancing the high-entropy effect and multi-element synergistic effect of the high-entropy alloy, optimizing the adsorption energy of the intermediate, increasing the active sites and catalytic activity of the material, and thus improving the efficiency of the water electrolysis reaction, the preferred electrodeposition temperature is 25–50 °C, the time is 10–30 min, and the current density is 0.05–0.2 A / cm². 2 The current density can be 0.05, 0.07, 0.09, 0.11, 0.13, 0.15, 0.17, 0.19, and 0.20 A / cm. 2 More preferably, the molar ratio of nickel salt, copper salt, iron salt, molybdenum salt and tungsten salt is (8-12):(3.1-5):(0.8-2.5):(0.6-3):1.

[0025] In a preferred embodiment, in step S1, the weight ratio of ammonium sulfate, sodium dodecyl sulfate, and sodium citrate is (0.0001–0.002):(0.0001–0.003):1, thereby further enabling nickel ions to exist in ionic form in the electrolyte solution and be reduced and deposited on the pretreated nickel substrate surface. Maintaining electrolyte balance: and further maintaining the acid-base balance of the electrolyte. A further preferred embodiment of step S1 includes: taking nickel salt, copper salt, iron salt, molybdenum salt, and tungsten salt as raw materials, mixing them with an aqueous solution of ammonium sulfate, sodium dodecyl sulfate, and sodium citrate, and adjusting the pH value to 3.5–6.0 using sulfuric acid to obtain an electroplating solution. This pH value can be 3.5, 3.7, 3.9, 4.1, 4.3, 4.6, 4.9, 5.2, 5.5, 5.8, and 6.0.

[0026] To further remove residual impurities from the nickel substrate surface, step S2 preferably involves pretreating the nickel substrate by sequentially chemically degreasing and acid-washing nickel mesh and / or nickel foam to obtain the pretreated nickel substrate. This further increases the active sites and catalytic activity of the alloy material, thereby further improving its electrochemical performance.

[0027] In another aspect, this invention provides a high-entropy alloy electrode material, obtained by the aforementioned preparation method. The high-entropy alloy electrode material is a Ni-Cu-Fe-Mo-W high-entropy alloy. This high-entropy alloy electrode not only improves reaction efficiency and reduces energy consumption, but its low-cost and high-safety preparation process also provides strong support for the commercialization and popularization of water electrolysis for hydrogen production. With continued research, high-entropy alloy electrodes are expected to play an even more important role in the future field of alkaline water electrolysis for hydrogen production.

[0028] In another aspect, this invention provides the application of a high-entropy alloy electrode material in the field of water electrolysis for hydrogen production, preferably as a catalyst for the oxygen evolution cathode and / or hydrogen evolution anode in water electrolysis. During the water electrolysis process, the high-entropy alloy can serve as a catalyst for both the cathode and anode, improving the efficiency of water splitting. Particularly under alkaline conditions, the high-entropy alloy electrode exhibits excellent performance in both hydrogen evolution and oxygen evolution reactions simultaneously.

[0029] The present application will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed in the present application.

[0030] Example 1

[0031] The substrate for the high-entropy alloy electrode is a nickel mesh, cut to 30mm × 30mm, which undergoes chemical degreasing and pickling to obtain a pretreated nickel substrate. Then, an electroplating solution is prepared for electrochemical deposition to prepare the high-entropy alloy electrode.

[0032] Specifically, the electroplating solution was prepared by using 6 mmol of NiSO4·6H2O, 2 mmol of CuSO4·6H2O, 1 mmol of FeSO4·7H2O, 0.6 mmol of Na2MoO4·2H2O, and 0.6 mmol of Na2WO4·2H2O as raw materials. Then, 0.5 mg of ammonium sulfate, 0.5 mg of sodium dodecyl sulfate, and 2 g of sodium citrate were dissolved in 100 mL of water. After mixing the raw materials, the pH was adjusted to 4 with sulfuric acid. A nickel mesh was placed in the electroplating solution as the working electrode (cathode), ensuring it was positioned opposite the carbon plate (reference electrode). The temperature of the electroplating solution was adjusted to 30°C. The electroplating time was 20 minutes, and the current density was 0.05 A / cm². 2 After electrodeposition, the electrode is rinsed with distilled water to remove undeposited metal ions and impurities, and then dried to obtain the Ni-Cu-Fe-Mo-W high-entropy alloy electrode material. The SEM image of this electrode material is shown below. Figure 1 As shown.

[0033] Example 2

[0034] The only difference from Example 1 is that after mixing the raw materials with it, the pH is adjusted to 5 with sulfuric acid.

[0035] Example 3

[0036] The only difference from Example 1 is that the current density is 0.2 A / cm². 2 .

[0037] Comparative Example 1

[0038] The only difference from Example 1 is that no electrodeposition treatment was performed, and the electrode material was a pretreated nickel substrate.

[0039] Performance testing

[0040] The electrode materials prepared in the above examples and comparative examples were used as cathodes and anodes in water electrolysis for hydrogen production, respectively. A 30% KOH solution was used as the electrolyte, and the electrolyte was set at 80°C and 500 mA / cm². 2 The cell voltage of the above electrodes in water electrolysis for hydrogen production was measured at the specified current density. The test results are shown in Table 1.

[0041] Table 1

[0042] Experiment No. Cathode material Anode material Cell voltage (V) Test 1 Example 1 electrode material Example 1 electrode material 1.85 Test 2 Comparative Example 1 electrode material Example 2 electrode material 1.95 Test 3 Example 3 electrode material Comparative Example 1 electrode material 2.05 Test 4 Comparative Example 1 electrode material Comparative Example 1 electrode material 2.25

[0043] As can be seen from the above description, the embodiments of the present invention achieve the following technical effects:

[0044] As shown in Table 1, the high-entropy alloy electrode material prepared by the technical solution of the present invention has significant advantages over the traditional nickel mesh electrode. Due to the high-entropy effect and multi-element synergistic effect of the high-entropy alloy, the adsorption energy of the intermediate can be optimized, the active sites and catalytic activity of the material can be increased, thereby improving the efficiency of water electrolysis reaction and effectively reducing cell voltage and energy consumption. Figure 2 The elemental distribution map of the high-entropy alloy electrode material prepared in Example 1 is shown below. Figure 2 It can be seen that Ni, Cu, Fe, Mo, and W elements are uniformly distributed on the surface of the electrode material, proving the successful preparation of the high-entropy alloy electrode.

[0045] While this specification contains numerous specific implementation details, these should not be construed as limiting the scope of any invention or the scope of the claims, but rather are primarily intended to describe features of specific embodiments of a particular invention. Certain features described in the various embodiments herein may also be implemented in combination in a single embodiment. Conversely, various features described in a single embodiment may also be implemented separately in various embodiments or in any suitable sub-combination. Furthermore, while features may function in certain combinations as described above and even initially claimed in this way, one or more features from a claimed combination may be removed from that combination in some cases, and a claimed combination may refer to a sub-combination or a variation thereof.

[0046] Similarly, although the operations are depicted in a specific order in the accompanying drawings, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or requiring all illustrated operations to be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system modules and components in the above embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0047] Thus, specific embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. In some cases, the actions recited in the claims may be performed in a different order and still achieve the desired result. Furthermore, the processes depicted in the drawings are not necessarily shown in a specific order or sequence to achieve the desired result. In some implementations, multitasking and parallel processing may be advantageous.

[0048] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0049] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a high-entropy alloy electrode material, characterized in that, The preparation method includes: Step S1: Take nickel salt, copper salt, iron salt, molybdenum salt and tungsten salt as raw materials, and mix them with an aqueous solution of ammonium sulfate, sodium dodecyl sulfonate and sodium citrate to obtain an electroplating solution; Step S2: The pretreated nickel substrate is electrodeposited in the electroplating solution, and then washed and dried in sequence to obtain the high-entropy alloy electrode material.

2. The preparation method according to claim 1, characterized in that, In step S1, the nickel salt is selected from one or more of nickel sulfate hexahydrate, nickel chloride hexahydrate, or nickel nitrate hexahydrate; and / or The copper salt is selected from one or more of copper sulfate hexahydrate, copper chloride dihydrate, or copper nitrate trihydrate; and / or The iron salt is selected from one or more of ferric sulfate heptahydrate, ferric nitrate nonahydrate, or ferric chloride hexahydrate; and / or The molybdenum salt is selected from one or more of sodium molybdate dihydrate, ammonium molybdate tetrahydrate, or ammonium heptamolybdate tetrahydrate; and / or The tungsten salt is selected from one or more of sodium tungstate dihydrate, ammonium tungstate decahydrate, or ammonium paratungstate.

3. The preparation method according to claim 1 or 2, characterized in that, In step S2, the electrodeposition treatment is carried out at a temperature of 25–50°C for 10–30 minutes, and with a current density of 0.05–0.2 A / cm². 2 .

4. The preparation method according to any one of claims 1 to 3, characterized in that, The molar ratio of the nickel salt, the copper salt, the iron salt, the molybdenum salt, and the tungsten salt is (8-12):(3.1-5):(0.8-2.5):(0.6-3):

1.

5. The preparation method according to any one of claims 1 to 4, characterized in that, In step S1, the weight ratio of ammonium sulfate, sodium dodecyl sulfonate and sodium citrate is (0.0001~0.002):(0.0001~0.003):

1.

6. The preparation method according to any one of claims 1 to 5, characterized in that, In step S2, the pretreated nickel substrate includes: taking nickel mesh and / or foamed nickel and performing chemical degreasing and pickling treatments in sequence to obtain the pretreated nickel substrate.

7. The preparation method according to any one of claims 1 to 6, characterized in that, Step S1 includes: taking nickel salt, copper salt, iron salt, molybdenum salt and tungsten salt as raw materials, mixing them with an aqueous solution of ammonium sulfate, sodium dodecyl sulfonate and sodium citrate, and then adjusting the pH value to 3.5-6.0 with sulfuric acid to obtain the electroplating solution.

8. A high-entropy alloy electrode material, characterized in that, The high-entropy alloy electrode material is obtained by the preparation method of the high-entropy alloy electrode material according to any one of claims 1 to 7, and the high-entropy alloy electrode material is a Ni-Cu-Fe-Mo-W high-entropy alloy.

9. An application of the high-entropy alloy electrode material as described in claim 8, characterized in that, The high-entropy alloy electrode material is used in the field of water electrolysis for hydrogen production.

10. The application according to claim 9, characterized in that, The high-entropy alloy electrode material serves as the catalyst for the oxygen evolution cathode and / or hydrogen evolution anode in water electrolysis.

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