Electrolysis water oxygen evolution reaction membrane catalyst and preparation method thereof

Abstract

The application discloses an electrolytic water oxygen evolution reaction film catalyst and a preparation method thereof, relates to the technical field of electrolytic water catalyst materials, and has the technical scheme as follows: metal plates of Fe, Co, Ni, Cu and Zn are cut to obtain fan-shaped metal sheets of Fe, Co, Ni, Cu and Zn; the fan-shaped metal sheets of Fe, Co, Ni, Cu and Zn are spliced into a cylindrical target to obtain a multi-metal composite target; and the base is subjected to radio frequency magnetron sputtering under vacuum conditions with the multi-metal composite target as the target to obtain the electrolytic water oxygen evolution reaction film catalyst. The film surface forms a nano array structure, the film contains five kinds of cations of Fe, Co, Ni, Cu and Zn, and presents a dual-phase high-entropy oxide structure; the film catalyst has high activity and good stability. The synthesis method has the advantages of simple and efficient and safe preparation process, low cost, strong controllability, wide applicability and suitability for industrial production.

Description

Technical Field

[0001] This invention relates to the field of water electrolysis catalyst materials technology, and more specifically, to a thin-film catalyst for the oxygen evolution reaction of water electrolysis and its preparation method. Background Technology

[0002] In recent years, the massive consumption of fossil fuels has not only triggered an energy crisis, but the large amounts of byproducts emitted from their combustion have also exacerbated increasingly severe global warming and air pollution. To alleviate the energy crisis and environmental pollution, there is an urgent need to find greener and more environmentally friendly energy alternatives. Against this backdrop, hydrogen, as a zero-carbon energy carrier, has attracted widespread attention due to its high energy density, green nature, and sustainability. However, currently, over 95% of the world's hydrogen production comes from fossil fuel reforming, a process that emits large amounts of CO2, undoubtedly contradicting the original intention of carbon reduction. In contrast, approximately 3%-5% of hydrogen is produced through water electrolysis, a process with zero CO2 emissions. More importantly, hydrogen production through water electrolysis can convert intermittent and geographically limited renewable energy sources such as wind and solar power into zero-carbon chemical energy storage.

[0003] Currently, the main reason why large-scale hydrogen production via water electrolysis is difficult to achieve is the excessive power consumption. In particular, the oxygen evolution reaction (OER) at the anodic end of water electrolysis involves a complex four-electron transfer process. Its slow kinetics require a high voltage input, which severely limits the development of hydrogen production via water electrolysis.

[0004] In recent years, noble metal oxides such as RuO2 and IrO2 have been commercially used as anolyte oxygen evolution catalysts, but their high cost and scarcity have greatly limited their widespread industrial application. High-entropy oxides are a new type of oxide material formed by the reaction of five or more cations with oxygen ions in equimolar or near-equimolar ratios. Since Rost, Maria, and Curtarolo first reported rock-salt-type high-entropy oxides in 2015, they have attracted great attention from researchers as an emerging material, promoting the development of high-entropy ceramic materials (carbides, sulfides, fluorides, etc.) and their applications in dielectrics, magnetism, hydrogen storage, and energy conversion. Among them, high-entropy oxides, due to their abundant active sites, tunable specific surface area, stable crystal structure, unique geometric compatibility, and electronic structure, show broad application prospects in the field of electrocatalysis. Existing literature (Tang, Lina, et al. High Configuration Entropy Activated Lattice Oxygen for O2 Formation on Perovskite Electrocatalyst. Advanced Functional Materials (2022): 2112157.) reports the preparation of high-entropy perovskite (ABO3) cobaltate catalysts via the sol-gel method. These catalysts contain five cations: Mg, Mn, Fe, Co, and Ni. The catalysts exhibit optimal OER activity at a cobalt content of 20 mol%, displaying an overpotential of 320 mV and a low Tafel slope of 45 mV·dec⁻¹ at a current density of 10 mA·cm⁻², achieving performance nearly at the level of noble metal oxides. This suggests a bright future for the application of high-entropy oxides in OER catalyst materials.

[0005] However, current methods for preparing catalysts for the oxygen evolution reaction in water electrolysis often employ sol-gel methods and ball milling, which have drawbacks such as relatively complex process control, small production volumes, and long production cycles, and are still some distance from large-scale industrial production. Zhao et al. from Wuhan University (Zhao S, et al. Preparation and electrocatalytic properties of (FeCrCoNiAl0.1)Ox high-entropy oxide and NiCo-(FeCrCoNiAl0.1)Oheterojunction films. Journal of Alloys and Compounds, 2021:159108.) prepared (FeCrCoNiAl) catalysts using the widely used industrial magnetron sputtering method. 0.1 )O xHigh-entropy oxide thin films, used as catalysts for the oxygen evolution reaction (OER) in water electrolysis, provide a reference for the industrial preparation of OER catalysts. However, the overpotential of this catalyst is too high at 381 mV, failing to fully utilize the excellent catalytic activity of high-entropy materials. Although subsequent annealing at 700 °C for 5 hours can reduce the overpotential of the OER catalyst to 327 mV, it significantly increases energy and time consumption, hindering industrial-scale promotion.

[0006] Therefore, developing more advanced magnetron sputtering processes to prepare higher-performance thin-film catalysts for the oxygen evolution reaction (OER) in water electrolysis is a crucial pathway to industrializing hydrogen production through water electrolysis. Numerous studies have shown that surface nanostructures can effectively increase the catalyst surface area, thereby enhancing the number of active sites and charge conductivity; and biphase heterojunction structures can alter the electronic structure of the catalyst, improving its activity. These two points represent important directions for the design of high-performance OER catalysts for water electrolysis. Summary of the Invention

[0007] To ensure the excellent performance of the oxygen evolution reaction (OER) catalyst in water electrolysis while reducing catalyst costs and enabling large-scale production, this invention provides a thin-film catalyst for OER and its preparation method. In this method, relatively inexpensive Fe, Co, Ni, Cu, and Zn metal plates are used as raw materials. Industrial-grade magnetron sputtering is employed as the preparation method, and a (FeCoNiCuZn)O high-entropy oxide thin film is obtained through tilting sputtering. This film can serve as a thin-film catalyst for OER in water electrolysis. The catalyst possesses a surface nanoarray and a dual-phase heterojunction structure (salt rock + spinel structure). It exhibits excellent catalytic performance for the OER reaction at 10 mA cm⁻¹. -2 The overpotential is 300mV; in the 50-hour stability test, the voltage change is only 0.19%. The electrochemical activity and stability reach the level of noble metal RuO2 catalysts; the cost is lower, it can be used with industrial equipment, the process is simple, and it has the potential for large-scale industrial preparation.

[0008] The above-mentioned technical objective of the present invention is achieved through the following technical solution: a method for preparing a thin-film catalyst for the oxygen evolution reaction in water electrolysis, specifically comprising the following steps:

[0009] S1: Cut Fe metal sheet, Co metal sheet, Ni metal sheet, Cu metal sheet and Zn metal sheet respectively to obtain Fe sector metal sheet, Co sector metal sheet, Ni sector metal sheet, Cu sector metal sheet and Zn sector metal sheet;

[0010] S2: Assemble the Fe sector-shaped metal sheet, Co sector-shaped metal sheet, Ni sector-shaped metal sheet, Cu sector-shaped metal sheet and Zn sector-shaped metal sheet into a cylindrical target material to obtain a multi-metal composite target;

[0011] S3: Under vacuum conditions, the substrate is subjected to radio frequency magnetron sputtering using the multi-metal composite target as the target material to obtain the thin film catalyst for the oxygen evolution reaction of water electrolysis.

[0012] Furthermore, the diameters of the Fe, Co, Ni, Cu, and Zn sector-shaped metal sheets are independently 60-120 mm, and their thicknesses are independently 2-6 mm.

[0013] Furthermore, in the multi-metal composite target, the area percentage of the Fe sector metal sheet is 15%, the area percentage of the Co sector metal sheet is 20%, the area percentage of the Ni sector metal sheet is 25%, the area percentage of the Zn sector metal sheet is 20%, and the area percentage of the Cu sector metal sheet is 20%.

[0014] Furthermore, the radio frequency magnetron sputtering employs a tilting deposition process, which includes sequential pre-sputtering and re-sputtering.

[0015] Furthermore, in the tilted deposition process, the distance between the substrate and the target is set to 15-20cm during sputtering, and the angle between the substrate base and the target plane is 75-85 degrees.

[0016] Furthermore, the pre-sputtering time is 15-25 min, the sputtering power is 80-120 W, and argon and oxygen are introduced during the pre-sputtering process. The pressure of the argon is 0.5-1 Pa, and the pressure of the oxygen is 0-0.05 Pa.

[0017] Furthermore, during the resputtering process, 0.4-0.8 Pa of argon and 0.3-0.5 Pa of oxygen are introduced, and the sputtering power of the resputtering is 80-120 W, with a duration of 1.5-3 h.

[0018] The present invention also provides a thin film catalyst for the oxygen evolution reaction of water electrolysis prepared by the above preparation method, wherein the thin film catalyst for the oxygen evolution reaction of water electrolysis forms a surface nanoarray structure with nanorods having a diameter of about 50 nm.

[0019] Furthermore, the thin-film catalyst has a two-phase structure composed of a salt rock phase and a spinel phase.

[0020] Furthermore, it includes the following elements in atomic percentages: 50.5% O, 9.0% Fe, 9.7% Co, 10.6% Ni, 10.8% Cu, and 9.4% Zn.

[0021] Furthermore, the thickness of the thin film catalyst for the oxygen evolution reaction in water electrolysis is 0.8 nm-1.2 μm, and the diameter of the thin film grains is 5-20 nm.

[0022] In summary, the present invention has the following beneficial effects:

[0023] 1. This invention uses spliced ​​multi-metal composite targets and employs radio frequency magnetron sputtering tilted deposition to obtain a thin film catalyst for the oxygen evolution reaction in water electrolysis. It has the advantages of simple operation process, low cost, high yield, short production cycle, and no pollution.

[0024] 2. The thin-film catalyst for oxygen evolution reaction (OER) prepared by this invention has a surface nanoarray structure. The film contains five cations: Fe, Co, Ni, Cu, and Zn, and has a biphase heterojunction structure inside, exhibiting excellent OER catalytic activity and performance stability. This is attributed to the fact that the surface nanoarray structure of the film increases the number of active sites and charge conduction performance on the catalyst surface; the heterojunction structure improves the electronic structure in the catalyst and enhances the intrinsic activity of the catalyst.

[0025] 3. This invention uses common transition metals as raw materials and does not contain rare precious metal elements; the thin film catalyst for the oxygen evolution reaction of water electrolysis is prepared by magnetron sputtering. This thin film catalyst is easy to attach to the substrate of different devices and has no harsh requirements on the rough surface of the substrate, showing excellent adaptability to the service environment and flexibility of use. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the magnetron sputtering process used in Example 1;

[0027] Figure 2 The images are scanning electron microscope (SEM) images of the surface and cross-section of the (FeCoNiCuZn)O thin film obtained in Example 1, where (a) is a surface morphology image and (b) is a cross-sectional morphology image.

[0028] Figure 3 This is a grazing X-ray diffraction pattern of the (FeCoNiCuZn)O thin film obtained in Example 1;

[0029] Figure 4 These are the transmission electron microscope morphology, electron diffraction, and elemental distribution diagrams of the (FeCoNiCuZn)O thin film obtained in Example 1;

[0030] Figure 5 This is a comparison chart of the LSV curves of the (FeCoNiCuZn)O thin film obtained in Example 1 and other oxide thin films;

[0031] Figure 6 This is a comparison chart of the Tafel slope curves of the (FeCoNiCuZn)O thin film obtained in Example 1 and other oxide thin films;

[0032] Figure 7 This is the 50-hour chronopotential curve of the (FeCoNiCuZn)O thin film obtained in Example 1. Detailed Implementation

[0033] The following is in conjunction with the appendix Figure 1-7 The present invention will be described in further detail below.

[0034] Example: A method for preparing a thin-film catalyst for the oxygen evolution reaction in water electrolysis, specifically including the following steps:

[0035] S1: Cut Fe metal sheet, Co metal sheet, Ni metal sheet, Cu metal sheet and Zn metal sheet respectively to obtain Fe sector metal sheet, Co sector metal sheet, Ni sector metal sheet, Cu sector metal sheet and Zn sector metal sheet;

[0036] S2: Assemble the Fe sector-shaped metal sheet, Co sector-shaped metal sheet, Ni sector-shaped metal sheet, Cu sector-shaped metal sheet and Zn sector-shaped metal sheet into a cylindrical target material to obtain a multi-metal composite target;

[0037] S3: Under vacuum conditions, the substrate is subjected to radio frequency magnetron sputtering using the multi-metal composite target as the target material to obtain the thin film catalyst for the oxygen evolution reaction of water electrolysis.

[0038] Unless otherwise specified, all raw materials used in this invention are commercially available products in the field.

[0039] This invention involves cutting Fe metal plates, Co metal plates, Ni metal plates, Cu metal plates, and Zn metal plates to obtain Fe fan-shaped metal sheets, Co fan-shaped metal sheets, Ni fan-shaped metal sheets, Cu fan-shaped metal sheets, and Zn fan-shaped metal sheets, respectively.

[0040] In this invention, the purity of the Fe metal plate, Co metal plate, Ni metal plate, Cu metal plate and Zn metal plate is all higher than 99.90%.

[0041] In this invention, the diameter of the Fe fan-shaped metal sheet, Co fan-shaped metal sheet, Ni fan-shaped metal sheet, Cu fan-shaped metal sheet and Zn fan-shaped metal sheet is preferably 60-120 mm, and the thickness is preferably 2-6 mm.

[0042] The Fe, Co, Ni, Cu, and Zn sector-shaped metal sheets are assembled into a cylindrical target to obtain a multi-metal composite target.

[0043] In this invention, the area percentage of the Fe sector metal sheet in the multi-metal composite target is preferably 15%, the area percentage of the Co sector metal sheet is preferably 20%, the area percentage of the Ni sector metal sheet is preferably 25%, the area percentage of the Zn sector metal sheet is preferably 20%, and the area percentage of the Cu sector metal sheet is preferably 20%.

[0044] In this invention, the Fe sector metal sheet, Co sector metal sheet, Ni sector metal sheet, Cu sector metal sheet and Zn sector metal sheet are ultrasonically cleaned sequentially with alcohol, acetone and deionized water before use.

[0045] The present invention preferably uses a clamp to fix the multi-metal hybrid target to the target base.

[0046] After obtaining the multi-metal composite target, the present invention performs radio frequency magnetron sputtering on the substrate under vacuum conditions using the multi-metal composite target as the target material to obtain the thin film catalyst for the water electrolysis oxygen evolution reaction.

[0047] In this invention, the vacuum degree of the vacuum condition is preferably 1.5 × 10⁻⁶. -4 -2.5×10 -4 Pa, more preferably 2.0 × 10 Pa -4 Pa.

[0048] In this invention, the substrate is a metal or carbon fiber substrate, preferably a nickel substrate.

[0049] In this invention, the radio frequency magnetron sputtering preferably includes pre-sputtering and re-sputtering performed sequentially: the pre-sputtering is to remove oxides and surface-adsorbed micro-impurities from the target surface before the formal film deposition, bombarding the impurities on the target surface and converting them into gas for removal; simultaneously, the pre-sputtering can form a metal-oxide transition layer on the metal substrate surface. The re-sputtering is the formal sputtering film deposition, where the sputtered target atoms react with the reactive gas and slowly deposit onto the substrate to obtain a thin film.

[0050] In this invention, the pre-sputtering time is 15-25 min, more preferably 20 min, and the sputtering power is 80-120 W, more preferably 100 W. Argon and oxygen are introduced during the pre-sputtering, the pressure of the argon is 0.5-1 Pa, and the pressure of the oxygen is 0-0.05 Pa.

[0051] In this invention, during the resputtering process, 0.4-0.8 Pa of argon and 0.3-0.5 Pa of oxygen are introduced, more preferably 0.6 Pa of argon and 0.4 Pa of oxygen are introduced, the sputtering power of the resputtering is 80-120 W, more preferably 100 W, and the time is 1.5-3 h, more preferably 2 h.

[0052] In this invention, the pre-sputtering and re-sputtering processes employ an inclined deposition process, with the distance between the substrate and the target material more preferably being 15-20 cm, and the angle between the substrate base and the target material plane more preferably being 75-85 degrees.

[0053] After the radio frequency magnetron sputtering is completed, the sample deposited after sputtering is taken out after the vacuum chamber temperature has cooled naturally to room temperature. A (FeCoNiCuZn)O high-entropy oxide film is obtained on the surface, which can be used as a thin film catalyst for the oxygen evolution reaction of water electrolysis.

[0054] The present invention also provides a thin-film catalyst for oxygen evolution reaction in water electrolysis prepared by the preparation method described above, wherein the thin-film catalyst for oxygen evolution reaction in water electrolysis has a biphase structure composed of a salt rock phase and a spinel phase.

[0055] In this invention, the thin-film catalyst for the oxygen evolution reaction of water electrolysis preferably comprises the following atomic percentages of elements: 51.5% O, 12.7% Fe, 11.6% Co, 12.8% Ni, 12.8% Cu, and 11.4% Zn, wherein each element is uniformly distributed and has the characteristics of a high-entropy oxide.

[0056] Preferably, the surface of the water electrolysis oxygen evolution reaction thin film catalyst forms a nanoarray of about 50 nm with a thickness of 0.8 μm-1.2 μm and a film grain diameter of 5-20 nm, more preferably 5-15 nm.

[0057] In this invention, the thin-film catalyst for the oxygen evolution reaction in water electrolysis operates at 10 mA·cm⁻¹. -2 The oxygen evolution reaction overpotential can reach 300mV, and the Tafel slope can be as low as 64.51mV / dec.

[0058] Example 1:

[0059] S1: First, take metal plates (Fe, Co, Ni, Cu, Zn) with a purity higher than 99.90%, and cut them into fan-shaped pieces with a diameter of 60mm, a thickness of 5mm, and different arc sizes using a wire cutting machine. The area percentage of the fan-shaped pieces is as follows: 15% Fe fan-shaped metal sheet, 20% Zn fan-shaped metal sheet, 20% Cu fan-shaped metal sheet, 20% Co fan-shaped metal sheet, and 25% Ni fan-shaped metal sheet.

[0060] S2: Clean each sector-shaped metal sheet sequentially with alcohol, acetone, and deionized water using ultrasonic cleaning for 5 minutes; assemble the sector-shaped metal sheets into a cylindrical target and fix it to the target base with a clamp to obtain a multi-metal hybrid target;

[0061] S3: Clean the single-crystal silicon (100) substrate material sequentially with alcohol, acetone and deionized water using ultrasonic cleaning for 5 minutes;

[0062] S4: Load the cleaned single-crystal silicon (100) substrate material into the RF magnetron sputtering vacuum chamber, close the chamber door, and evacuate to 2.0 × 10⁻⁶. -4 Pa;

[0063] S5: Pre-sputter a mixed metal target for 20 minutes, sputtering power 100W, argon gas is introduced during sputtering, and the argon gas pressure is 0.8Pa;

[0064] S6: End pre-sputtering, and sputter the mixed metal target again. During sputtering, 0.6 Pa argon gas and 0.4 Pa oxygen gas are introduced, the sputtering power is 100 W, and the sputtering time is 2 h.

[0065] S7: After the magnetron sputtering vacuum chamber has cooled to room temperature, the sputtered sample is taken out, and an electrolytic oxygen evolution reaction film is obtained on its surface. The thickness of the electrolytic oxygen evolution reaction film is 1.0 μm, and the grain size is 5-15 nm.

[0066] Figure 1 This is a schematic diagram of the magnetron sputtering process used in Example 1 of the present invention. This sputtering process employs a FeCoNiCuZn mixed target and tilted sputtering technology to obtain a (FeCoNiCuZn)O thin-film catalyst for the oxygen evolution reaction in water electrolysis through two sputtering processes.

[0067] Figure 2 The images shown are scanning electron microscope images of the surface and cross-section of the (FeCoNiCuZn)O water electrolysis oxygen evolution reaction film catalyst obtained in Example 1 of this invention. (a) is a surface morphology image and (b) is a cross-sectional morphology image, indicating that the (FeCoNiCuZn)O water electrolysis oxygen evolution reaction film is a typical nanoarray film structure.

[0068] Figure 3 The grazing X-ray diffraction (GIXRD) pattern of the (FeCoNiCuZn)O water electrolysis oxygen evolution reaction (OER) film shows that the prepared (FeCoNiCuZn)O water electrolysis OER catalyst has a two-phase structure composed of a rocksalt structure and a spinel structure. This two-phase structure can form a heterojunction, thereby improving the catalytic performance of the film in the OER reaction.

[0069] Figure 4 The images show the transmission electron microscope (TEM) morphology, selected area electron diffraction (SED) pattern, and elemental distribution of the thin film micro-region. It is evident that the elements are uniformly distributed without significant agglomeration, consistent with the characteristics of a high-entropy oxide. The electron diffraction rings confirm that the film consists of two phases: salt rock and spinel. The atomic percentages of O, Fe, Co, Ni, Cu, and Zn in the thin film are shown in Table 1.

[0070] Table 1. Atomic percentage of each element in the oxygen evolution reaction membrane of water electrolysis.

[0071] element O Fe Co Ni Cu Zn Content (at%) 50.5 9.0 9.7 10.6 10.8 9.4

[0072] Figure 5The LSV curves of the (FeCoNiCuZn)O thin-film catalyst for the oxygen evolution reaction in water electrolysis are compared with those of other oxide thin-film catalysts. It can be seen that the (FeCoNiCuZn)O thin-film catalyst exhibits better performance at 10 mA·cm⁻¹. -2 The oxygen evolution reaction overpotential is about 300mV, which is better than other oxide film catalysts and even reaches the level of noble metal oxide catalysts.

[0073] Figure 6 The Tafel slope curves of the (FeCoNiCuZn)O thin-film catalyst for the oxygen evolution reaction (OER) in water electrolysis are compared with those of other oxide thin-film catalysts. It is evident that the Tafel slope of the (FeCoNiCuZn)O thin-film catalyst during the OER is significantly lower than that of other thin-film catalysts (only 64.51 mV / dec), indicating that the OER process is mainly controlled by the Tafel step, demonstrating superior chemical reaction kinetics.

[0074] Figure 7 The 50-hour chronopotential curves for the thin-film catalyst of (FeCoNiCuZn)O in the water electrolysis oxygen evolution reaction are shown. It can be seen that at a stable current density of 10 mA·cm⁻¹... -2 Under these conditions, the voltage change was only 0.19% over 50 hours, indicating that the thin-film catalyst has excellent service stability.

[0075] Example 2: Same as Example 1, except that the composite target used is any one of MgCoNiCuZn, CoNiCuZn, or CrCoNiCuZn. The different elemental composition of the prepared thin film leads to a higher overpotential and Tafel slope (e.g., ...). Figure 5 , 6 In other words, the catalytic performance of oxygen evolution reaction is not as good as that of (FeCoNiCuZn)O thin film catalyst.

[0076] Example 3: Same as Example 1, except that the sputtering time was 4 hours. The thickness of the resulting water electrolysis oxygen evolution reaction film was about 2 μm. Microcracks appeared on the surface of the film, which led to a decrease in the service stability of the film catalyst.

[0077] Example 4:

[0078] Similar to Example 1, the only difference is that the resputtering time is 1 hour, and the thickness of the resulting water electrolysis oxygen evolution reaction film is about 0.6 μm. The film surface coverage is insufficient, which leads to a decrease in the catalytic performance of the oxygen evolution reaction.

[0079] This specific embodiment is merely an explanation of the present invention and is not intended to limit the invention. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they are within the scope of the claims of the present invention.

Claims

1. A method for preparing a thin-film catalyst for the oxygen evolution reaction in water electrolysis, characterized in that: Specifically, the following steps are included: S1: Cut the Fe metal plate, Co metal plate, Ni metal plate, Cu metal plate and Zn metal plate respectively to obtain Fe fan-shaped metal sheets, Co fan-shaped metal sheets, Ni fan-shaped metal sheets, Cu fan-shaped metal sheets and Zn fan-shaped metal sheets; S2: Assemble the Fe sector-shaped metal sheet, Co sector-shaped metal sheet, Ni sector-shaped metal sheet, Cu sector-shaped metal sheet and Zn sector-shaped metal sheet into a cylindrical target material to obtain a multi-metal composite target; S3: Under vacuum conditions, using the multi-metal composite target as the target material, the substrate is subjected to radio frequency magnetron sputtering to obtain the thin film catalyst for the oxygen evolution reaction of water electrolysis. The radio frequency magnetron sputtering adopts a tilted deposition process, which includes pre-sputtering and re-sputtering performed sequentially. The tilted deposition process is set to a distance of 15-20 cm between the substrate and the target during sputtering, and an angle of 75-85 degrees between the substrate base and the target plane. The pre-sputtering time is 15-25 min, the sputtering power is 80-120 W, and argon and oxygen are introduced during the pre-sputtering process. The pressure of the argon is 0.5-1 Pa, and the pressure of the oxygen is 0-0.05 Pa. The thin film catalyst for the oxygen evolution reaction of water electrolysis forms a surface nanoarray structure with nanorods having a diameter of 50 nm. The thin-film catalyst has a two-phase structure consisting of a salt rock phase and a spinel phase.

2. The method for preparing a thin-film catalyst for the oxygen evolution reaction in water electrolysis according to claim 1, characterized in that: The diameters of the Fe, Co, Ni, Cu, and Zn sector-shaped metal sheets are independently 60–120 mm, and their thicknesses are independently 2–6 mm.

3. A method for preparing a thin-film catalyst for the oxygen evolution reaction in water electrolysis according to claim 1 or 2, characterized in that: The area percentage of the Fe sector metal sheet in the multi-metal composite target is 15%, the area percentage of the Co sector metal sheet is 20%, the area percentage of the Ni sector metal sheet is 25%, the area percentage of the Zn sector metal sheet is 20%, and the area percentage of the Cu sector metal sheet is 20%.

4. The method for preparing a thin-film catalyst for the oxygen evolution reaction in water electrolysis according to claim 1, characterized in that: During the resputtering process, argon gas at 0.4–0.8 Pa and oxygen gas at 0.3–0.5 Pa are introduced. The resputtering power is 80–120 W, and the time is 1.5–3 h.

5. A thin-film catalyst for oxygen evolution reaction in water electrolysis prepared by any one of claims 1 to 4, characterized in that: Elements including the following atomic percentages: 50.5% O, 9.0% Fe, 9.7% Co, 10.6% Ni, 10.8% Cu and 9.4% Zn.

6. The thin-film catalyst for the oxygen evolution reaction in water electrolysis according to claim 5, characterized in that: The thickness of the thin-film catalyst for the oxygen evolution reaction in water electrolysis is 0.8 nm to 1.2 μm, and the diameter of the thin-film grains is 5 to 20 nm.

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