Preparation method and application of high-entropy layered double hydroxide oxygen evolution catalyst

Abstract

The invention discloses a preparation method and application of a high-entropy layered double hydroxide oxygen evolution catalyst, and relates to the field of oxygen evolution reaction catalysis, and the preparation method comprises the following steps: S1, washing foamed nickel in absolute ethyl alcohol and deionized water, and then carrying out ultrasonic treatment in a hydrochloric acid solution to obtain pretreated foamed nickel; s2, adding ferric salt, cobalt salt, nickel salt, manganese salt, zinc salt and a proper amount of urea into deionized water, then adding ammonium fluoride, and uniformly stirring to obtain a mixed solution; and S3, transferring the mixed solution and the pretreated foamed nickel into a reaction kettle, carrying out a hydrothermal reaction, and washing and drying the obtained product to obtain the high-entropy layered double hydroxide oxygen evolution catalyst. According to the method, the key regulation and control effect of NH4F on the structure, chemical and electro-catalytic properties of HELDHs in the synthesis process of the HELDHs is analyzed, and the performance enhancement is attributed to NH4F-induced morphology and crystal engineering and catalytic active cation vacancies generated in situ through selective leaching of Zn < 2 + > and adsorption of sulfate under the alkaline condition.

Description

Technical Field

[0001] This invention relates to the field of oxygen evolution reaction catalysis, and more particularly to a method for preparing a high-entropy layered double hydroxide oxygen evolution catalyst and its application. Background Technology

[0002] The oxygen evolution reaction (OER) is a key process in sustainable energy conversion technologies such as water electrolysis, metal-air batteries, and regenerative fuel cells. However, its inherently slow kinetics in alkaline environments severely limit the overall efficiency of these systems. This challenge has driven extensive research into efficient, stable, and globally abundant OER electrocatalysts.

[0003] High entropy materials (HEMs), consisting of single-phase structures composed of five or more metallic elements, have become a highly promising research platform in the field of electrocatalysis in recent years. Their unique lattice distortion, elemental synergistic effects, and high configurational entropy allow for the regulation of electronic structure and catalytic performance that breaks through the limitations of traditional binary or ternary systems. Among them, high entropy layered double hydroxides (HELDHs), with their intrinsically active layered structure, abundant catalytic sites, and compositional flexibility, are particularly suitable for alkaline OERs and have therefore attracted widespread attention.

[0004] Besides composition, the OER activity of HELDHs is also greatly influenced by their structure and defect characteristics. Specific surface area, porosity, structural anisotropy, oxygen vacancies, and dopant elements collectively determine mass / charge transport, accessibility of active sites, electrolyte diffusion, and electronic energy levels. Although morphology and defect engineering are effective strategies for optimizing performance, achieving precise and large-scale control of these characteristics in high-entropy systems remains a significant challenge.

[0005] In hydrothermal synthesis, anions in solution play a crucial role as structure-directing agents, significantly influencing nucleation kinetics, growth pathways, and final morphology. They also regulate defect chemistry, including the formation of oxygen vacancies and surface termination states. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a method for preparing a high-entropy layered double hydroxide oxygen evolution catalyst and its application. Utilizing ammonium fluoride (NH4F) as a bifunctional modifier for hydrothermal synthesis, this method not only achieves a controllable morphological evolution of the catalyst from two-dimensional nanosheets to three-dimensional nanoflowers, but also utilizes the etching effect of fluoride ions to induce zinc ion (Zn) ion (NH4F) formation. 2+ Selective leaching of fluorine-containing compounds (fluorine) in situ created abundant cation vacancy defects in the crystal lattice, enabling fluorine doping. Through morphology control and vacancy defect engineering, the electronic structure was significantly optimized, lowering the reaction energy barrier. The resulting high-entropy layered double hydroxide oxygen evolution catalyst exhibited excellent OER performance in alkaline water electrolysis, reaching a maximum efficiency of 1.0 A cm⁻¹. -2It exhibits low overpotential and excellent long-term stability under industrial-grade high current density.

[0007] To achieve the above objectives, the present invention provides a method for preparing a high-entropy layered double hydroxide oxygen evolution catalyst, comprising the following steps:

[0008] S1. Wash the nickel foam in anhydrous ethanol and deionized water, and then sonicate it in hydrochloric acid solution to obtain pretreated nickel foam.

[0009] S2. Add iron salt, cobalt salt, nickel salt, manganese salt, zinc salt and appropriate amount of urea to deionized water, then add ammonium fluoride, stir well to obtain a mixed solution;

[0010] S3. The mixed solution and the pretreated nickel foam are transferred to a reactor for hydrothermal reaction. The resulting product is washed and dried to obtain the high-entropy layered double hydroxide oxygen evolution catalyst.

[0011] Furthermore, in step S1, the nickel foam is ultrasonically treated in a 1-5M hydrochloric acid solution for 5-30 minutes.

[0012] Furthermore, in step S2, the metal salt is any one of nitrate, chloride, acetate, or sulfate.

[0013] Furthermore, in step S2, the molar ratio of metal salt, urea, and ammonium fluoride is 1:5~15:2~8.

[0014] Furthermore, in step S3, the hydrothermal temperature is 100~140℃, and the hydrothermal time is 2~12h.

[0015] Furthermore, in step S3, the obtained nickel foam is washed with deionized water 1 to 3 times and dried at 40 to 80°C.

[0016] The present invention also provides the application of the high-entropy layered double hydroxide oxygen evolution catalyst as an oxygen evolution reaction catalyst.

[0017] This invention analyzes the effect of ammonium fluoride (NH4F) as a regulator on the performance of basic electrocatalysts (OERs) during the synthesis of high-entropy layered double hydroxides (HELDHs). By varying the NH4F concentration during hydrothermal synthesis, a series of HELDHs with different morphologies and defect densities were successfully prepared. Their electrochemical performance was comprehensively evaluated and correlated with structural characteristics. The results show that even slight changes in NH4F content can lead to significant differences in OER activity and stability. This invention provides fundamental insights into the structure-activity relationship of high-entropy electrocatalysts and offers a rational synthetic strategy for the design of advanced OER materials.

[0018] The present invention has the following beneficial effects:

[0019] (1) This invention analyzes the key regulatory role of NH4F in the synthesis of high-entropy layered double hydroxides (HELDHs) on their structure, chemistry, and electrocatalytic performance. The HELDHs catalyst prepared in Example 1 exhibits excellent OER performance at 100 mA·cm⁻¹. -2 The overpotential is as low as 285 mV, and the Tafel slope is 30.26 mV·dec. -1 This performance enhancement is attributed to NH4F-induced morphology and crystal engineering, as well as the effect of Zn under alkaline conditions. 2+ The selective leaching and adsorption of catalytically active cation vacancies generated in situ by sulfate.

[0020] (2) When the high-entropy layered double hydroxide HELDH-2 prepared in this invention is integrated into AEMWE as an anode, the electrolyzer achieves a high performance of 2.05V at the relevant current density and exhibits significant stability during operation for more than 300 hours.

[0021] (3) This invention not only provides fundamental insights into anion-directed catalyst design and defect engineering, but also establishes the potential application value of HELDHs as next-generation sustainable hydrogen production OER electrocatalysts. Attached Figure Description

[0022] Figure 1 The image shows a scanning electron microscope (SEM) image of HELDH-0 in Comparative Example 1.

[0023] Figure 2 This is a scanning electron microscope (SEM) image of HELDH-2 in Example 1.

[0024] Figure 3 This is a scanning electron microscope (SEM) image of HELDH-4 in Example 2.

[0025] Figure 4 This is a scanning electron microscope (SEM) image of HELDH-8 in Example 3.

[0026] Figure 5 The X-ray diffraction (XRD) patterns of the products obtained in Comparative Example 1 and Examples 1-3 are shown.

[0027] Figure 6 This is a transmission electron microscope (TEM) image of HELDH-2 in Example 1.

[0028] Figure 7The electrocatalytic OER performance of the catalyst obtained in this invention is shown in the following figures: (ab) LSV curve; (c) Tafel plot; (d) capacitance current density; (e) EIS Nyquist plot of the prepared sample; (f) initial LSV curve of HELDH-2 and LSV curves after 5000 and 10000 cycles.

[0029] Figure 8 Applications of the high-entropy layered double hydroxide oxygen evolution catalyst obtained in this invention: (a) Schematic diagram of AEMWE; (b) Performance of IrO2||Pt / C and HELDH-2||Pt / C electrolyzers at 40°C; (c) Polarization curves of the HELDH-2||Pt / C electrolyzer at different temperatures; (d) Performance of the HELDH-2||Pt / C electrolyzer at 40°C and 1000 mA·cm⁻¹. -2 Durability tests were conducted. Detailed Implementation

[0030] The specific embodiments of the present invention will now be clearly and completely described in conjunction with the accompanying drawings.

[0031] The reagents used in the examples include:

[0032] Cobalt nitrate hexahydrate (Co(NO3)2・6H2O, ≥98%), nickel nitrate hexahydrate (Ni(NO3)2・6H2O, ≥98%), zinc nitrate hexahydrate (Zn(NO3)2・6H2O, ≥99%), manganese nitrate tetrahydrate (Mn(NO3)2・4H2O, ≥99%), ferric nitrate nonahydrate (Fe(NO3)3・9H2O, ≥99%), ammonium fluoride (NH4F, ≥98.0%), urea (CO(NH2)2, ≥95%), and potassium hydroxide (KOH, 85%) were purchased from Adamas Reagents Ltd.; 5 wt% perfluorosulfonic acid resin solution (Nafion, a mixture soluble in low-fatty alcohols and water) was purchased from Aladdin Reagents Ltd.; reference platinum catalyst (20% Pt supported on activated carbon) was purchased from AlphaEsa Reagents Ltd.; ethanol was analytical grade and purchased from multiple suppliers; deionized water (DIW) was supplied by Elga Prepared using the Purelabflex system; all chemical reagents were used directly without further purification.

[0033] The present invention will be further described below with reference to specific embodiments and accompanying drawings:

[0034] Comparative Example 1

[0035] A piece of nickel foam (NF, 2×3 cm) was washed in anhydrous ethanol and deionized water, and then sonicated in 3M hydrochloric acid solution for 15 minutes to clean the surface. Subsequently, 0.2 mmol ferric nitrate nonahydrate, 0.2 mmol cobalt nitrate hexahydrate, 0.2 mmol nickel nitrate hexahydrate, 0.2 mmol manganese nitrate tetrahydrate, 0.2 mmol zinc nitrate hexahydrate, and 10 mmol urea were added to 60 mL of deionized water. The mixture and the pretreated nickel foam were then transferred to a 100 mL PTFE-lined stainless steel autoclave and maintained at 120°C for 6 hours. The resulting nickel foam was washed with deionized water and dried at 60°C to obtain a high-entropy layered double hydroxide oxygen evolution catalyst without ammonium fluoride doping, named HELDH-0.

[0036] Example 1

[0037] A piece of nickel foam (NF, 2×3 cm) was washed in anhydrous ethanol and deionized water, and then sonicated in 3M hydrochloric acid solution for 15 minutes to clean the surface. Subsequently, 0.2 mmol ferric nitrate nonahydrate, 0.2 mmol cobalt nitrate hexahydrate, 0.2 mmol nickel nitrate hexahydrate, 0.2 mmol manganese nitrate tetrahydrate, 0.2 mmol zinc nitrate hexahydrate, and 10 mmol urea were added to 60 mL of deionized water. 2.0 mmol ammonium fluoride was added, and the mixture was stirred for 10 minutes. The mixture and the pretreated nickel foam were then transferred to a 100 mL PTFE-lined stainless steel autoclave and maintained at 120°C for 6 hours. The resulting nickel foam was washed with deionized water and dried at 60°C to obtain the high-entropy layered double hydroxide oxygen evolution catalyst, named HELDH-2.

[0038] Example 2

[0039] A piece of nickel foam (NF, 2×3 cm) was washed in anhydrous ethanol and deionized water, and then sonicated in 3M hydrochloric acid solution for 15 minutes to clean the surface. Subsequently, 0.2 mmol ferric nitrate nonahydrate, 0.2 mmol cobalt nitrate hexahydrate, 0.2 mmol nickel nitrate hexahydrate, 0.2 mmol manganese nitrate tetrahydrate, 0.2 mmol zinc nitrate hexahydrate, and 10 mmol urea were added to 60 mL of deionized water. 4.0 mmol ammonium fluoride was added, and the mixture was stirred for 10 minutes. The mixture and the pretreated nickel foam were then transferred to a 100 mL PTFE-lined stainless steel autoclave and maintained at 120°C for 6 hours. The resulting nickel foam was washed with deionized water and dried at 60°C to obtain the high-entropy layered double hydroxide oxygen evolution catalyst, named HELDH-4.

[0040] Example 3

[0041] A piece of nickel foam (NF, 2×3 cm) was washed in anhydrous ethanol and deionized water, and then sonicated in 3M hydrochloric acid solution for 15 minutes to clean the surface. Subsequently, 0.2 mmol ferric nitrate nonahydrate, 0.2 mmol cobalt nitrate hexahydrate, 0.2 mmol nickel nitrate hexahydrate, 0.2 mmol manganese nitrate tetrahydrate, 0.2 mmol zinc nitrate hexahydrate, and 10 mmol urea were added to 60 mL of deionized water. 8.0 mmol ammonium fluoride was added, and the mixture was stirred for 10 minutes. The mixture and the pretreated nickel foam were then transferred to a 100 mL PTFE-lined stainless steel autoclave and maintained at 120°C for 6 hours. The resulting nickel foam was washed with deionized water and dried at 60°C to obtain the high-entropy layered double hydroxide oxygen evolution catalyst, named HELDH-8.

[0042] Example 4

[0043] A piece of nickel foam (NF, 2×3 cm) was washed in anhydrous ethanol and deionized water, and then sonicated in 1M hydrochloric acid solution for 30 minutes to clean the surface. Subsequently, 0.2 mmol ferric nitrate nonahydrate, 0.2 mmol cobalt nitrate hexahydrate, 0.2 mmol nickel nitrate hexahydrate, 0.2 mmol manganese nitrate tetrahydrate, 0.2 mmol zinc nitrate hexahydrate, and 5 mmol urea were added to 60 mL of deionized water. 2.0 mmol ammonium fluoride was added, and the mixture was stirred for 10 minutes. The mixture and the pretreated nickel foam were then transferred to a 100 mL PTFE-lined stainless steel autoclave and maintained at 140°C for 4 hours. The resulting nickel foam was washed with deionized water and dried at 60°C to obtain the high-entropy layered double hydroxide oxygen evolution catalyst.

[0044] Example 5

[0045] A piece of nickel foam (NF, 2×3 cm) was washed in anhydrous ethanol and deionized water, and then sonicated in 5M hydrochloric acid solution for 5 minutes to clean the surface. Subsequently, 0.2 mmol ferric nitrate nonahydrate, 0.2 mmol cobalt nitrate hexahydrate, 0.2 mmol nickel nitrate hexahydrate, 0.2 mmol manganese nitrate tetrahydrate, 0.2 mmol zinc nitrate hexahydrate, and 15 mmol urea were added to 60 mL of deionized water. 2.0 mmol ammonium fluoride was added, and the mixture was stirred for 10 minutes. The mixture and the pretreated nickel foam were then transferred to a 100 mL PTFE-lined stainless steel autoclave and maintained at 100°C for 12 hours. The resulting nickel foam was washed with deionized water and dried at 60°C to obtain the high-entropy layered double hydroxide oxygen evolution catalyst.

[0046] Figure 1The image shows a SEM image of HELDH-0 in Comparative Example 1. As can be seen from the image, HELDH-0 synthesized without the addition of NH4F forms a flat nanosheet array.

[0047] Figures 2-4 The images show SEM images of HELDH-2, HELDH-4, and HELDH-8 from Examples 1-3. As can be seen from the images, after the introduction of NH4F (HELDH-2), the morphology evolved into interconnected flower-like nanosheets. Figure 2 Further increasing the NH4F content (HELDH-4) leads to thicker and larger nanosheets. Figure 3 Ultimately, HELDH-8 exhibits a densely packed, blocky microstructure.

[0048] Figure 5 The X-ray diffraction (XRD) patterns of the products obtained in Comparative Example 1 and Examples 1-3 show the crystallinity trend: HELDH-0 is mainly amorphous, while the crystallinity gradually increases with the increase of NH4F content. HELDH-8 shows obvious diffraction peaks in the range of 10°-40°, highlighting the key role of NH4F in regulating the structural order.

[0049] Figure 6 The transmission electron microscope (TEM) image of HELDH-2 in Example 1 confirms its ultrathin wrinkled nanosheet structure. This structure provides a high density of exposed surface sites by promoting charge transfer and mass transport, which is beneficial to electrochemical activity. All constituent metals (Fe, Co, Ni, Mn, Zn) and oxygen are uniformly spatially distributed in the nanosheet, confirming the formation of a homogeneous high-entropy phase.

[0050] The working electrode is a prepared electrocatalyst supported on NF, with an area of ​​1.0 cm². 2 .

[0051] Electrode system:

[0052] Electrochemical performance tests were performed in a standard three-electrode electrolytic cell system, controlled by a CHI760E electrochemical workstation. In this system, the prepared electrode had an area of ​​1.0 cm². 2 The load was NF as the working electrode, the mercury oxide electrode (Hg / HgO, filled with 1.0M KOH solution) as the reference electrode, and the high-purity graphite rod as the counter electrode. The electrolyte was 1.0M KOH aqueous solution.

[0053] Electrocatalytic performance measurement:

[0054] Electrochemical measurements were performed using a standard three-electrode system (1.0M KOH electrolyte) on an electrochemical workstation (CHI 760E, CH Instruments).

[0055] Before conducting electrochemical tests, oxygen was continuously bubbled into the electrolyte for approximately 30 minutes to ensure oxygen saturation, and this atmosphere was maintained during the tests. First, in an oxygen-saturated 1.0M KOH solution, oxygen was bubbled at 5 mV s⁻¹. -1 Linear sweep voltammetry (LSV) was performed at the scan rate to obtain polarization curves and evaluate the oxygen evolution activity of the catalyst. Secondly, the activity was measured at 20 to 100 mV s. -1 Cyclic voltammetry (CV) tests were performed at different scan rates to evaluate the electrochemically active surface area of ​​the catalyst by calculating the double-layer capacitance. Simultaneously, electrochemical impedance spectroscopy (EIS) was conducted in the frequency range of 100 kHz to 0.01 Hz under AC voltage amplitude of 5 mV to analyze electrode reaction kinetics.

[0056] Figure 7 The electrocatalytic OER performance of the catalyst obtained in this invention is as follows: Figure 7 As shown in ab, the HELDH-2 catalyst exhibits optimal performance, reaching 100 mA·cm⁻¹. -2 The lowest overpotential required for current density (285mV) is achieved, outperforming HELDH-0 (306mV), HELDH-4 (358mV), HELDH-8 (403mV), and FeCo LDH (397mV), FeCoNi LDH (361mV), and FeCoNiMn LDH (321mV). Furthermore, as... Figure 7 As shown in c, HELDH-2 exhibits the best reaction kinetics, with a Tafel slope (30.26 mV·dec). -1 () Less than HELDH-0 (41.92mV・dec) -1 ), HELDH-4 (61.58mV·dec) -1 ) and HELDH-8 (84.97mV·dec -1 This confirms that the OER reaction pathway on the HELDH-2 surface is simpler. For example... Figure 7 As shown in Figure d, to investigate the source of enhanced catalytic activity, the electrochemical active surface area (ECSA) was estimated by calculating the electrochemical double-layer capacitance (Cdl). The results show that the order of Cdl values ​​is: HELDH-2 (2.32 mF·cm). -2 HELDH-0 (1.69 mF·cm) > HELDH-0 -2 HELDH-4 (1.10 mF·cm) > HELDH-4 -2 HELDH-8 (0.81 mF·cm) -2 This indicates that HELDH-2 has the largest electrochemical active surface area, providing more reactive sites; such as Figure 7 As shown in Figure e, the electrochemical impedance spectroscopy (EIS) results further reveal that HELDH-2 exhibits the lowest charge transfer resistance (Rct) among this series of samples. This indicates that the material possesses enhanced charge transfer capability and electronic conductivity, thereby accelerating reaction kinetics. This result is also consistent with its minimum Tafel slope. These results collectively highlight the crucial influence of NH4F content on catalytic performance, which plays a role by regulating the number and exposure of active sites. Figure 7 f shows the initial LSV curve of HELDH-2 and the curves after 5000 and 10000 CV cycles. Although between 5000 and 10000 cycles, 100 mA·cm⁻¹ -2 The overpotential remained almost unchanged, but the overpotential after two cycles was significantly lower than the initial measurement, indicating that an activation process exists during electrochemical aging.

[0057] The preparation processes for FeCo LDH, FeCoNi LDH, and FeCoNiMn LDH are described in applications CN202411062577.5 and CN 202211291729.X, which are existing technologies.

[0058] Example 6: Anion Exchange Membrane Water Electrolyzer

[0059] The catalyst was used as the anode to evaluate its practical application potential in water splitting (Figure 8a). Commercial platinum-carbon (Pt / C) was sprayed onto an anion exchange membrane (AEM) and used as both the cathode and separator. For comparison, commercial Pt / C (cathode) and IrO2 (anode) electrolyzers were tested under the same conditions.

[0060] HELDH-2||Pt / C electrolytic cell at 40°C, 1.0 A・cm -2 The cell exhibits an extremely low voltage (2.05 V) at the current density (Figure 8b). When the temperature is increased to 80°C, the increased OH⁻ ion mobility in the AEM further reduces the cell voltage to 1.86 V at the same current density. This value is significantly better than that of the IrO₂||Pt / C electrolyzer, which operates at 1 A·cm⁻¹ at 40°C. -2 The required voltage is 2.24V, indicating that HELDH-2 has excellent catalytic activity in alkaline water splitting (Figure 8c).

[0061] In terms of durability, the HELDH-2||Pt / C electrolyzer exhibits excellent stability: at 1A·cm -2After 200 hours of continuous operation at a stepped current density, no significant voltage decay was observed (Figure 8d). These findings highlight the excellent performance of HELDH-2 as an AEMWE anode catalyst and confirm its practical application potential in efficient and robust alkaline water splitting.

[0062] This invention analyzes the key regulatory role of NH4F in the synthesis of HELDHs, including their structure, chemical properties, and electrocatalytic performance. The HELDH-2 catalyst prepared with the optimal amount of NH4F exhibits excellent OER performance at 100 mA·cm⁻¹. -2 The overpotential is as low as 285 mV, and the Tafel slope is 30.26 mV·dec. -1 This performance enhancement is attributed to NH4F-induced morphology and crystal engineering, as well as the effect of Zn under alkaline conditions. 2+ The selective leaching and in-situ adsorption of sulfate-generated catalytically active cation vacancies facilitate the selective leaching and adsorption of HELDH-2. Furthermore, when HELDH-2 is integrated as the anode into an AEMWE, the cell achieves high performance of 2.05 V at a relevant current density and exhibits significant stability over more than 300 hours of operation. This invention not only provides fundamental insights into anion-directed catalyst design and defect engineering but also establishes the potential application value of HELDHs as next-generation sustainable hydrogen production OER electrocatalysts.

[0063] The above are merely preferred embodiments of the present invention, and only describe the implementation of the present invention. They are not intended to limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the technical 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 a high-entropy layered double hydroxide oxygen evolution catalyst, characterized by, Includes the following steps: S1. Wash the nickel foam in anhydrous ethanol and deionized water, and then sonicate it in hydrochloric acid solution to obtain pretreated nickel foam. S2. Add iron salt, cobalt salt, nickel salt, manganese salt, zinc salt and appropriate amount of urea to deionized water, then add ammonium fluoride, stir well to obtain a mixed solution; S3. The mixed solution and the pretreated nickel foam are transferred to a reactor for hydrothermal reaction. The resulting product is washed and dried to obtain the high-entropy layered double hydroxide oxygen evolution catalyst.

2. The method for preparing a high-entropy layered double hydroxide oxygen evolution catalyst according to claim 1, characterized in that, In step S1, the nickel foam is ultrasonically treated in a 1-5M hydrochloric acid solution for 5-30 minutes.

3. The method for preparing a high-entropy layered double hydroxide oxygen evolution catalyst according to claim 1, characterized in that, In step S2, the metal salt can be any one of nitrate, chloride, acetate, or sulfate.

4. The method for preparing a high-entropy layered double hydroxide oxygen evolution catalyst according to claim 3, characterized in that, In step S2, the molar ratio of metal salt, urea, and ammonium fluoride is 1:5~15:2~8.

5. The method for preparing a high-entropy layered double hydroxide oxygen evolution catalyst according to claim 1, characterized in that, In step S3, the hydrothermal temperature is 100~140℃ and the hydrothermal time is 2~12h.

6. The method for preparing a high-entropy layered double hydroxide oxygen evolution catalyst according to claim 1, characterized in that, In step S3, the obtained nickel foam is washed with deionized water 1 to 3 times and dried at 40 to 80°C.

7. A high-entropy layered double hydroxide oxygen evolution catalyst, characterized in that, It is prepared by the method described in any one of claims 1 to 6.

8. The application of the high-entropy layered double hydroxide oxygen evolution catalyst according to claim 7, characterized in that, It was used as a catalyst for the oxygen evolution reaction.

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