Substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm, preparation method and application thereof
By constructing antiferromagnetic manganese-iridium intermetallic compound nanofilms at low temperature on a metal oxide single-crystal substrate, the problems of insufficient activity and stability of existing catalysts and high energy consumption in the preparation process have been solved, realizing efficient and environmentally friendly catalyst preparation and clean energy application.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIHANG UNIV
- Filing Date
- 2026-04-24
- Publication Date
- 2026-06-05
Smart Images
Figure CN122147438A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of catalysts for oxygen evolution reaction, and in particular to a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm, its preparation method, and its application. Background Technology
[0002] The oxygen evolution reaction (OER), a core half-reaction in clean energy conversion and storage technologies such as water splitting, metal-air batteries, and renewable fuel cells, suffers from slow kinetics and high overpotential, severely limiting the overall system's energy efficiency. Therefore, developing efficient, stable, and cost-effective OER electrocatalysts is a key challenge in promoting the development of a green hydrogen economy.
[0003] Currently, commercial OER catalysts heavily rely on noble metal-based materials, especially oxides of iridium (Ir) and ruthenium (Ru) (such as IrO2 and RuO2). While these materials exhibit excellent activity, their low stability and high price severely hinder large-scale industrial applications. In recent years, research has shifted to two alternative strategies: one is to develop catalysts with transition metal content, such as oxides, hydroxyl oxides, and phosphides of transition metals (Fe, Co, Ni, Mn); the other is to maximize the utilization efficiency and stability of noble metal atoms by constructing alloys, core-shell structures, or utilizing support effects. Among transition metal systems, manganese (Mn)-based oxides have attracted attention due to their abundant reserves, variable valence states, and environmental friendliness; however, their poor intrinsic conductivity and low active site density limit their performance. Combining noble metals (such as Ir) with transition metals (such as Mn) to form composite metal or alloy systems is considered an effective approach to achieving both high activity and stability.
[0004] Currently, the iridium-manganese-based electrocatalytic materials and their preparation methods have certain limitations in terms of technical routes, material structures, and preparation methods. One method, employing an impregnation-high-temperature reduction approach, loads iridium-manganese precursors onto a carbon support and then performs prolonged heat treatment at 900–1100 °C in a reducing atmosphere to form an ordered intermetallic compound structure, resulting in a bifunctional electrocatalytic material of carbon-supported iridium-manganese intermetallic compounds. However, its oxygen evolution reaction (OER) activity remains insufficient, especially with a large overpotential at higher current densities, indicating room for improvement in catalytic efficiency and stability. Furthermore, the synthesis process requires prolonged heat treatment at high temperatures, resulting in significant energy consumption and demanding equipment requirements, which is detrimental to large-scale preparation and cost control. In contrast, an Ir-Mn-based composite catalyst based on polyhexabenzanthracene network material (PBN) uses atomic layer deposition to disperse manganese and iridium atoms on a PBN substrate. This material exhibits high activity and good durability in both OER and HER, but its preparation involves various organic solvents (such as N,N-dimethylformamide, dichloromethane, methanol, tetrahydrofuran, etc.) and highly corrosive reagents (concentrated hydrochloric acid, nitric acid, ferric chloride, etc.), making the synthesis steps cumbersome. Furthermore, the polymeric precursors and organic solutions used can easily cause environmental pollution and wastewater treatment problems. In addition, the synthesis of PBN itself requires multiple reaction steps and strict atmosphere control, resulting in a complex and time-consuming process, which is not conducive to industrial scale-up and green production. In summary, existing technologies still have significant shortcomings in terms of catalyst activity (especially in OER), synthesis energy consumption, environmental friendliness, and process simplification, providing a clear direction for the improvement and innovation of this invention.
[0005] In view of this, the present invention is hereby proposed. Summary of the Invention
[0006] The purpose of this invention is to provide a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm, its preparation method, and its applications. This invention utilizes magnetron sputtering to construct antiferromagnetic manganese-iridium intermetallic compound nanofilms at low temperature and in situ on a metal oxide single-crystal substrate. This solves key technical problems such as the difficulty in synergistically improving the activity and stability of existing oxygen evolution reaction catalysts, low utilization of the precious metal iridium, high energy consumption, heavy pollution, poor process repeatability, and easy corrosion and deactivation of the support in high-temperature thermal reduction or wet chemical preparation processes. Simultaneously, it overcomes the defects of uneven dispersion of active components, poor interfacial contact, and insufficient structural controllability in traditional supported catalysts.
[0007] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted: In a first aspect, the present invention provides a substrate-loaded antiferromagnetic manganese-iridium intermetallic compound nanofilm, comprising: a substrate, and an antiferromagnetic manganese-iridium intermetallic compound nanofilm formed by magnetron sputtering loaded on the surface of the substrate. The substrate includes any one of magnesium oxide substrate, strontium titanate substrate, and niobium-doped strontium titanate substrate.
[0008] Furthermore, the substrate is a (100) oriented single-crystal magnesium oxide substrate.
[0009] Furthermore, the length of the substrate is 3-10 mm, the width of the substrate is 3-10 mm, and the thickness of the substrate is 0.3-0.7 mm.
[0010] Furthermore, the antiferromagnetic manganese-iridium intermetallic compound nanofilm has a polycrystalline structure.
[0011] Furthermore, the thickness of the antiferromagnetic manganese-iridium intermetallic compound nanofilm is 10~100 nm.
[0012] Furthermore, the molar ratio of manganese to iridium in the antiferromagnetic manganese-iridium intermetallic compound nanofilm is (45~50):(50~55).
[0013] Furthermore, the grain size of the antiferromagnetic manganese-iridium intermetallic compound nanofilm is 3~8nm; the interplanar spacing includes a family of crystal planes with d1 of 0.18~0.23nm and d2 of 0.10~0.15nm.
[0014] In a second aspect, the present invention provides a method for preparing a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm as described in the first aspect, the method comprising: An antiferromagnetic manganese-iridium intermetallic compound nanofilm was deposited on the surface of the substrate by magnetron sputtering, using a manganese-iridium intermetallic compound as the target material, to obtain an antiferromagnetic manganese-iridium intermetallic compound nanofilm loaded on the substrate.
[0015] Furthermore, the parameters for the magnetron sputtering deposition include: temperature of 195~205 °C; argon flow rate of 20~30 mL / min; chamber pressure of 0.3~0.5 Pa; sputtering power of 55~65 W; and sputtering time of 5~40 min.
[0016] Furthermore, the deposition process includes pre-sputtering of the target material; wherein the pre-sputtering parameters include: temperature of 195~205 °C; argon flow rate of 20~30 mL / min; cavity pressure of 0.3~0.5 Pa; sputtering power of 55~65 W; and sputtering time of 10~20 min.
[0017] Furthermore, the deposition process includes a heat preservation treatment; wherein the temperature of the heat preservation treatment is 195~205 °C; and the heat preservation treatment time is 30~40 min.
[0018] Thirdly, the present invention provides the application of substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilms as described in the first aspect, or substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilms prepared by the preparation method described in the second aspect, in the preparation of electrocatalytic materials for oxygen evolution reaction.
[0019] Fourthly, the present invention provides an oxygen evolution reaction electrocatalyst material, wherein the oxygen evolution reaction electrocatalyst comprises a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm as described in the first aspect, or a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm prepared by the preparation method described in the second aspect.
[0020] Compared with the prior art, the present invention has the following beneficial effects: (1) The electrocatalytic material of the present invention uses magnesium oxide substrate, strontium titanate substrate, and niobium-doped strontium titanate substrate as substrates to support antiferromagnetic manganese-iridium intermetallic compound nanofilms prepared by magnetron sputtering. The substrate has a highly regular single crystal structure, which provides an ideal crystal template for the epitaxial growth of the film and ensures the high activity of the catalytic structure. The substrate also has ultra-high chemical and thermal stability, and the structure remains intact during preparation and use, without adverse reactions with the active metal components, thus improving the purity and stability of the catalyst. At the same time, the elements in the manganese-iridium intermetallic compound film are uniformly distributed and the crystal phase structure is reasonable, which effectively optimizes the electronic structure of the noble metal, takes into account both high catalytic activity and structural stability, and also reduces the amount of noble metal used, thus achieving a balance between performance and cost.
[0021] (2) The preparation method of the present invention uses magnetron sputtering technology to prepare catalytic materials. No organic solvents or corrosive reagents are used in the whole process, and no harmful waste liquid is generated. The process is clean and environmentally friendly, which is in line with the concept of green production. At the same time, the technology can achieve low temperature deposition, which greatly reduces the energy consumption of the preparation process, and can precisely control the composition and structure of the film to ensure the uniformity and density of the product. In addition, the process is highly controllable and repeatable, and the equipment is mature. It does not require complex multi-step reactions and strict atmosphere control, which simplifies the preparation process and is more conducive to industrial scale-up production.
[0022] (3) The electrocatalytic material described in this invention exhibits excellent catalytic activity and stability in the oxygen evolution reaction, and can be widely used in clean energy conversion and storage fields such as water splitting, metal-air batteries, and renewable fuel cells. It can effectively solve the problems of slow catalyst kinetics and high overpotential in existing technologies, and improve the overall energy efficiency of clean energy systems. This material breaks through the bottlenecks of traditional electrocatalytic materials in terms of activity, stability, and cost, and provides an innovative and feasible material solution for the large-scale implementation of clean energy technologies, contributing to the development of a green hydrogen economy, and has good industrial application prospects and market value. Attached Figure Description
[0023] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.
[0024] Figure 1 Characterization diagram of the substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm provided in Embodiment 1 of the present invention; wherein, Figure 1 a is a transmission electron microscope image of the antiferromagnetic manganese-iridium intermetallic compound nanofilm; Figure 1 b is a scanning transmission electron microscopy-energy dispersive spectroscopy (STEM-EDS) elemental distribution diagram of Ir element in antiferromagnetic manganese-iridium intermetallic compound nanofilms; Figure 1 c is the scanning transmission electron microscopy-energy dispersive spectroscopy elemental distribution diagram of Mn element in antiferromagnetic manganese-iridium intermetallic compound nanofilm; Figure 1 d is a high-resolution transmission electron microscope image of the interface region between the antiferromagnetic manganese-iridium intermetallic compound nanofilm and MgO. Figure 1 e is Figure 1 Magnified high-resolution transmission electron microscope image of the selected region in b; Figure 1 f is an atomic-resolution image showing the lattice spacing of an antiferromagnetic manganese-iridium intermetallic compound nanofilm.
[0025] Figure 2 Linear scanning voltammetry curves of the antiferromagnetic manganese-iridium intermetallic compound nanofilm supported on the substrate are provided for Example 1 and for the RuO2 film provided in Comparative Example 1.
[0026] Figure 3 A comparison of chronopotential curves of the substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm for Example 1 and the RuO2 film provided in Comparative Example 1 are shown.
[0027] Figure 4 Linear scanning voltammetric curves of the antiferromagnetic manganese-iridium intermetallic compound nanofilms supported on the substrate are provided for comparison of Examples 2-4.
[0028] Figure 5 Linear scanning voltammetric curves of the antiferromagnetic manganese-iridium intermetallic compound nanofilms supported on the substrate are provided for comparison in Examples 5-6. Detailed Implementation
[0029] Unless otherwise defined herein, the scientific and technical terms used in conjunction with this invention shall have the meanings commonly understood by one of ordinary skill in the art. The meaning and scope of terms shall be clear; however, in any case of potential ambiguity, the definitions provided herein shall prevail over any dictionary or foreign definitions. In this application, unless otherwise stated, the use of "or" means "and / or". Furthermore, the use of the term "comprising" and other forms is non-limiting.
[0030] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0031] In a first aspect, the present invention provides a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm, comprising: a substrate, and a manganese (Mn)-iridium (Ir) intermetallic compound nanofilm formed by magnetron sputtering and supported on the surface of the substrate; The substrate includes any one of magnesium oxide substrate, strontium titanate substrate, and niobium-doped strontium titanate substrate.
[0032] It should be noted that the antiferromagnetic manganese-iridium intermetallic compound nanofilm supported on the substrate described in this invention exhibits excellent electrocatalytic performance in the oxygen evolution reaction (OER), which can be attributed to the following aspects: First, the electronic structure modulation between Mn and Ir can alter the electron cloud distribution and energy level structure of iridium and manganese on the film surface, thereby affecting their adsorption behavior for key oxygen-containing reaction intermediates (such as *OH, *O, and *OOH). This modulation helps optimize the adsorption and desorption processes of these intermediates, making them more kinetic to the oxygen evolution reaction, thus reducing the reaction overpotential and enhancing catalytic activity.
[0033] Secondly, the intermetallic compound structure formed by Mn and Ir exhibits strong interatomic interactions, which helps improve the structural stability of the system. During electrocatalysis, the manganese in this thin film structure can, to a certain extent, replace and inhibit the deactivation behaviors of Ir, such as dissolution and aggregation, thereby enhancing the durability of the catalyst and enabling it to maintain high catalytic activity during long-term oxygen evolution reactions, achieving a synergistic improvement in activity and stability.
[0034] Furthermore, magnesium oxide (MgO), strontium titanate (SrTiO3), and niobium-doped strontium titanate were selected as substrates, providing excellent growth and support conditions for antiferromagnetic manganese-iridium intermetallic compound nanofilms. These substrates typically possess a (100) oriented single-crystal structure with regular atomic arrangement and a smooth surface, which is beneficial for the epitaxial growth of the film, thus forming a catalytic interface with a uniform structure and a reasonable distribution of active sites. Simultaneously, these substrates exhibit excellent chemical and thermal stability, and are less prone to side reactions with the active components during the reaction process, helping to maintain the structural integrity of the catalyst and the effectiveness of the active sites. Experimental results show that this system has low sensitivity to substrate type, and different substrates can all support the film to achieve stable and efficient oxygen evolution catalytic performance.
[0035] As an optional implementation, the substrate is a metal oxide single crystal substrate, and the substrate has a cubic (100) crystal plane.
[0036] It should be noted that compared with the carbon powder loading and polymer substrate loading methods used in existing technologies, using a series of metal oxide single-crystal substrates as substrates for loading intermetallic compound nanofilms has unique comprehensive advantages. First, their cubic (100) crystal planes have highly ordered atomic arrangements and excellent surface flatness, providing ideal crystal templates for the epitaxial growth of highly ordered metal or alloy films, which helps to form highly active catalytic structures. Second, MgO, SrTiO3, etc., have extremely high chemical and thermal stability (for example, the melting point of MgO is as high as 2852 °C), and can maintain structural integrity during magnetron sputtering deposition and subsequent high-temperature heat treatment, without adversely reacting with active metal components, thus ensuring the purity and stability of the catalyst. These characteristics make them ideal substrate materials for studying high-performance model catalysts and preparing functional films with well-defined structures.
[0037] In a preferred embodiment, the substrate is a (100) oriented single-crystal magnesium oxide substrate.
[0038] It should be noted that the present invention preferably uses (100) oriented single-crystal magnesium oxide (MgO) as the substrate. Compared with strontium titanate (SrTiO3) and niobium-doped strontium titanate substrates, magnesium oxide generally exhibits more prominent comprehensive advantages in terms of crystal structure matching, physicochemical stability and process adaptability.
[0039] First, the magnesium oxide (100) crystal plane has a regular cubic lattice structure, with ordered atomic arrangement and high surface flatness, which is conducive to the epitaxial growth process of antiferromagnetic manganese-iridium intermetallic compound nanofilms. This makes it easier to form a catalytic layer with high crystal quality and uniform structure, and promotes the uniform distribution of active sites, which helps to exert the intrinsic catalytic activity of the material.
[0040] Secondly, magnesium oxide has better chemical and thermal stability. During magnetron sputtering deposition and subsequent oxygen evolution reaction, it is less likely to undergo significant interfacial reactions with manganese and iridium active components. At the same time, it can suppress adverse phenomena such as interfacial diffusion, lattice distortion and component migration to a certain extent, thereby helping to maintain the stability of the substrate and film structure and ensuring the long-term stability of catalytic performance.
[0041] Furthermore, a relatively stable interfacial bond can usually be formed between the magnesium oxide substrate and the antiferromagnetic manganese-iridium intermetallic compound nanofilm, which is beneficial to improving the adhesion of the film and thus reducing the risk of detachment during bubble impact and long-term electrocatalysis. Meanwhile, magnesium oxide is widely available, inexpensive, and has a relatively mature preparation process, making it more conducive to large-scale preparation. In summary, using (100) oriented single-crystal magnesium oxide as the substrate helps to improve the process adaptability and application potential of the material system while ensuring catalytic activity and structural stability.
[0042] As an optional implementation, the length of the substrate is 3 to 10 mm, for example, it can be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc.
[0043] As an optional implementation, the width of the substrate is 3 to 10 mm, for example, it can be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, etc.
[0044] As an optional implementation, the thickness of the substrate is 0.3~0.7 mm, for example, it can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, etc.
[0045] As an optional implementation, the antiferromagnetic manganese-iridium intermetallic compound nanofilm has a polycrystalline structure.
[0046] It should be noted that the polycrystalline antiferromagnetic manganese-iridium intermetallic compound nanofilm formed by magnetron sputtering deposition in this invention is an important structural basis for achieving its excellent oxygen evolution reaction performance. Compared with single-crystal or low-defect structures, polycrystalline films contain a large number of grain boundaries, crystal planes, and structural discontinuities, which can significantly increase the number of surface active sites, thereby increasing the density of catalytic reaction sites per unit area and thus improving the overall reaction rate.
[0047] Meanwhile, the synergistic effect between different crystal planes in the polycrystalline structure enables the material surface to provide diverse adsorption environments, which is beneficial for matching different oxygen-containing intermediates (such as oxygen evolution intermediates) during the oxygen evolution reaction. * OH、 * O、 *The adsorption and conversion requirements of OOH can optimize the reaction pathway to a certain extent, promote the reaction kinetic process and reduce the overpotential.
[0048] Furthermore, polycrystalline thin films prepared by magnetron sputtering typically exhibit high density and good elemental uniformity, with tight grain boundary bonding and interface stability. During electrochemical reactions, they effectively suppress the dissolution, migration, and aggregation of active components, thereby mitigating structural degradation. This structural characteristic allows the film to maintain a stable active site structure even during prolonged oxygen evolution reactions, achieving a synergistic improvement in both catalytic activity and structural stability. In summary, the polycrystalline antiferromagnetic manganese-iridium intermetallic compound nanofilm constructed in this invention, through the combined effects of high-density active sites, synergistic effects of polycrystalline faces, and a stable and dense structure, enhances the catalytic efficiency of the oxygen evolution reaction while maintaining long-term operational stability, demonstrating significant comprehensive performance advantages.
[0049] As an optional implementation, the thickness of the antiferromagnetic manganese-iridium intermetallic compound nanofilm is 10~100 nm, for example, it can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, etc.
[0050] As an optional implementation, the molar ratio of manganese to iridium in the antiferromagnetic manganese-iridium intermetallic compound nanofilm is (45~50):(50~55); Among them, "45~50" can be, for example, 45, 46, 47, 48, 49, 50, etc.; Among them, "50~55" can be, for example, 50, 51, 52, 53, 54, 55, etc.
[0051] As an optional implementation, the antiferromagnetic manganese-iridium intermetallic compound nanofilm has a grain size of 3~8 nm; the interplanar spacing includes a family of crystal planes with d1 of 0.18~0.23 nm and d2 of 0.10~0.15 nm.
[0052] In a second aspect, the present invention provides a method for preparing a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm as described in the first aspect, the method comprising: An antiferromagnetic manganese-iridium intermetallic compound nanofilm was deposited on the surface of the substrate by magnetron sputtering, using a manganese-iridium intermetallic compound as the target material, to obtain an antiferromagnetic manganese-iridium intermetallic compound nanofilm loaded on the substrate.
[0053] It should be noted that this invention utilizes magnetron sputtering to deposit antiferromagnetic manganese-iridium intermetallic compound nanofilms on the surface of a specific substrate. This method is a material preparation technique that uses plasma generated by magnetron discharge for thin film deposition. Its working principle involves ionizing argon gas within a vacuum chamber using an electric field and orthogonal magnetic field to form plasma. High-energy ions in the plasma bombard the target material (manganese-iridium intermetallic compound), causing target atoms to be sputtered and deposited on the substrate surface to form a dense and uniform thin film. The main function of magnetron sputtering equipment is to prepare high-quality, highly adhesive functional thin film materials. Its core advantages are: low-temperature deposition, avoiding damage to the substrate material from high temperatures; uniform and dense thin films with good compositional controllability and easy atomic-level mixing; and a clean and environmentally friendly process, as the entire physical vapor deposition process does not require the use of organic solvents or generate harmful chemical waste. Furthermore, the process has good repeatability and is easy to scale up. These characteristics make it an ideal technology for preparing high-performance catalyst thin films.
[0054] As an optional implementation, the parameters for the magnetron sputtering deposition include: a temperature of 195–205 °C (e.g., 195 °C, 196 °C, 197 °C, 198 °C, 199 °C, 200 °C, 201 °C, 202 °C, 203 °C, 204 °C, 205 °C, etc.); an argon flow rate of 20–30 mL / min (e.g., 20 mL / min, 21 mL / min, 22 mL / min, 23 mL / min, 24 mL / min, 25 mL / min, 26 mL / min, 27 mL / min, 28 mL / min, 29 mL / min, 30 mL / min, etc.); and a chamber pressure of 0.3–0.5 Pa (e.g., 0.3 Pa, 0.32 Pa, 0.34 Pa, 0.36 Pa, 0.38 Pa, 0.4 Pa, 0.42 Pa, 0.44 Pa, 0.46 Pa). Pa, 0.48 Pa, 0.5 Pa, etc.; sputtering power is 55~65 W (e.g., 55 W, 56 W, 57 W, 58 W, 59 W, 60 W, 61 W, 62 W, 64 W, 65 W, etc.); sputtering time is 5~40 min (e.g., 5 min, 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, 22 min, 24 min, 26 min, 28 min, 30 min, 32 min, 34 min, 36 min, 38 min, 40 min, etc.).
[0055] It should be noted that this invention precisely limits the magnetron sputtering deposition parameters to a specific range. This parameter combination provides a stable and efficient process environment for the deposition of antiferromagnetic manganese-iridium intermetallic compound nanofilms, balancing film performance and process operability. Specifically, the temperature range avoids substrate lattice distortion and adverse interfacial reactions caused by high temperatures, while providing suitable surface diffusion energy for the deposited atoms, which is beneficial for improving the film's density and crystallinity. Excessively high temperatures can lead to a decrease in the proportion of manganese, affecting the film's catalytic performance and stability.
[0056] Specifically, the sputtering power is set to 55~65 W (particularly preferred to be 60 W), which effectively suppresses excessive bombardment of the film by high-energy particles while ensuring the deposition rate, reduces defect generation, and helps maintain the synergistic sputtering of Mn and Ir elements and compositional uniformity.
[0057] Meanwhile, the coordinated regulation of argon flow rate and cavity pressure makes the plasma discharge process more stable, the plasma distribution more uniform, and the ion bombardment energy more moderate, thereby ensuring that the sputtered particles have appropriate migration ability and deposition kinetic energy, so that Mn and Ir atoms can reach the substrate surface uniformly and form a dense and continuous thin film structure.
[0058] In addition, by controlling the sputtering time within the range of 5 to 40 minutes, the thickness and microstructure of the film can be adjusted. This ensures continuous film coverage and facilitates the formation of highly active polycrystalline manganese-iridium intermetallic compound structures.
[0059] In summary, the magnetron sputtering parameter range defined in this invention achieves controllable adjustment of the thin film growth process through the synergistic effect of multiple factors. This not only yields manganese-iridium nanofilms with uniform elemental distribution, dense structure, and excellent crystal quality, but also exhibits good process repeatability and equipment adaptability. It can operate stably without complex debugging, making it suitable for industrial-scale preparation. Furthermore, the resulting film maintains excellent catalytic activity and structural stability during the oxygen evolution reaction.
[0060] As an optional implementation, the deposition process further includes pre-sputtering of the target material; wherein the pre-sputtering parameters include: a temperature of 195~205 °C (e.g., 195 °C, 196 °C, 197 °C, 198 °C, 199 °C, 200 °C, 201 °C, 202 °C, 203 °C, 204 °C, 205 °C, etc.); an argon flow rate of 20~30 mL / min (e.g., 20 mL / min, 21 mL / min, 22 mL / min, 23 mL / min, 24 mL / min, 25 mL / min, 26 mL / min, 27 mL / min, 28 mL / min, 29 mL / min, 30 mL / min, etc.); and a cavity pressure of 0.3~0.5 Pa (e.g., 0.3 Pa, 0.32 Pa, 0.34 Pa, 0.36 Pa, 0.38 Pa, 0.4 Pa, 0.42 Pa, etc.). Pa, 0.44 Pa, 0.46 Pa, 0.48 Pa, 0.5 Pa, etc.; sputtering power is 55~65 W (e.g., 55 W, 56 W, 57 W, 58 W, 59 W, 60 W, 62 W, 64 W, 65 W, etc.); pre-sputtering time is 10~20 min (e.g., 10 min, 12 min, 14 min, 16 min, 18 min, 20 min, etc.).
[0061] It should be noted that this invention incorporates a pre-sputtering step before formal deposition, with the pre-sputtering process parameters being essentially consistent with subsequent deposition parameters. The pre-sputtering time is controlled within the range of 10–20 minutes. This process design plays a crucial role in improving the stability of the deposition process and the quality of the thin film. The pre-sputtering process under this parameter system allows the plasma state, gas flow field, and energy distribution within the vacuum chamber to reach a stable equilibrium in advance, thereby avoiding problems such as thin film composition deviations and structural inhomogeneities caused by unstable discharge or environmental fluctuations in the early stages of formal deposition, effectively improving process consistency and repeatability.
[0062] Meanwhile, pre-sputtering under the above conditions can thoroughly clean the surface of the manganese-iridium intermetallic compound target, effectively removing the oxide layer, adsorbed impurities and contaminants on its surface, exposing a fresh and stable metal interface on the target surface, reducing the possibility of impurities being introduced into the thin film from the source, and helping to ensure the compositional uniformity of the deposited thin film and the stable formation of the intermetallic compound phase.
[0063] Furthermore, controlling the pre-sputtering time within the range of 10-20 minutes ensures that the target material enters a stable sputtering state, making the sputtering rate and particle energy distribution tend to be constant. It also avoids unnecessary target material consumption and increased energy consumption due to excessively long pre-sputtering times. Based on this, formal deposition can proceed, resulting in antiferromagnetic manganese-iridium intermetallic compound nanofilms with uniform thickness, dense structure, and excellent interface quality, thereby further enhancing their catalytic activity and long-term operational stability in the oxygen evolution reaction. Therefore, this invention, by introducing a pre-sputtering step matched to the deposition parameters and reasonably limiting the pre-sputtering time, achieves multiple synergistic effects of pre-stabilization of the deposition environment, target surface purification, and sputtering state regulation, providing a strong guarantee for the controllable preparation of high-quality thin films.
[0064] As an optional implementation, the deposition process further includes a heat preservation treatment; wherein the temperature of the heat preservation treatment is 195~205 °C (e.g., 195 °C, 196 °C, 197 °C, 198 °C, 199 °C, 200 °C, 201 °C, 202 °C, 203 °C, 204 °C, 205 °C, etc.); and the heat preservation treatment time is 30~40 min (e.g., 30 min, 32 min, 34 min, 35 min, 36 min, 38 min, 40 min, etc.).
[0065] It should be noted that after deposition, the present invention performs a heat treatment for a certain period of time at the same temperature conditions (195~205 °C) as the deposition process. This process step plays an important role in further optimizing the structure and properties of the antiferromagnetic manganese-iridium intermetallic compound nanofilm. Maintaining the same heat treatment temperature as the deposition temperature effectively avoids the accumulation of thermal stress caused by sudden temperature changes, thereby reducing the generation of internal defects in the film and preventing crystal phase distortion or a decrease in the bonding force between the film and the substrate, ensuring the integrity and stability of the overall film structure. Simultaneously, the appropriate duration of heat treatment at 195~205 °C facilitates further diffusion and local rearrangement of Mn and Ir atoms within the film, gradually transforming the non-equilibrium deposition state into a relatively stable structure. This optimizes the crystal phase distribution and grain boundary state in the polycrystalline structure, improves the film's density and elemental distribution uniformity, and enhances the bonding strength within the intermetallic compound.
[0066] Furthermore, a suitable holding time can fully leverage atomic diffusion and structural optimization while avoiding abnormal grain growth or interface degradation caused by excessive time. Under the synergistic effect of the above process conditions, the obtained antiferromagnetic manganese-iridium intermetallic compound nanofilms can form a more stable and uniform microstructure, which is conducive to constructing a reasonably distributed catalytic active site and maintaining structural stability during the electrochemical reaction, thus exhibiting superior catalytic activity and long-term durability in the oxygen evolution reaction. This approach achieves further optimization and stabilization of the film structure, providing an important process guarantee for obtaining high-performance antiferromagnetic manganese-iridium intermetallic compound nanofilms.
[0067] As an optional implementation, the method for preparing the substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm specifically includes the following steps: (1) The substrate is fixed on the sample stage of the magnetron sputtering equipment using silver paste; (2) Place the sample stage with the substrate attached on the heating stage and heat and dry the silver paste; (3) Open the vacuum chamber of the magnetron sputtering equipment, replace the target material of the magnetron sputtering equipment with a manganese-iridium intermetallic compound target material, and then close and seal the vacuum chamber; (4) Turn on the cooling water circulation system; (5) Turn on the main power switch of the magnetron sputtering equipment to start the magnetron sputtering equipment; (6) Turn on the mechanical pump switch of the magnetron sputtering equipment to extract the air from the vacuum chamber of the magnetron sputtering and make the air pressure in the vacuum chamber reach below 10 Pa. (7) Turn on the molecular pump switch of the magnetron sputtering equipment, open the solenoid valve of the magnetron sputtering equipment, and extract the air from the vacuum chamber of the magnetron sputtering equipment to make the air pressure in the vacuum chamber reach 1×10 -5 Below Pa; (8) Place the sample stage with the substrate attached, with the substrate side facing down, in the transition chamber of the magnetron sputtering equipment; (9) Close the solenoid valve of the magnetron sputtering equipment, open the connection switch between the mechanical pump and the transition chamber, and use the mechanical pump to extract the air from the transition chamber; (10) Close the connection switch between the mechanical pump and the transition chamber, open the connection switch between the transition chamber and the vacuum chamber, and place the sample stage into the vacuum chamber; (11) Close the connection switch between the transition chamber and the vacuum chamber, and open the solenoid valve to bring the air pressure in the vacuum chamber back to 1×10⁻⁶. -5 Below Pa; (12) Turn on the heating equipment switch, set the heating program, raise the temperature of the vacuum chamber to the temperature required for magnetron sputtering, and maintain it at that temperature; (13) Turn on the argon gas switch and the argon gas flow controller to control the argon gas flow rate and introduce argon gas; (14) Adjust the gas pressure in the vacuum chamber to maintain the pressure required for magnetron sputtering; (15) Turn on the target sputtering power supply and adjust the sputtering power to the power required for magnetron sputtering; (16) Close the sample stage baffle to block the sample stage, open the target baffle switch, open the target baffle, and start pre-sputtering; (17) After the pre-sputtering is completed, open the sample stage baffle and start sputtering; (18) After sputtering is completed, first close the sample stage baffle, then close the target baffle; (19) Adjust the power of the target sputtering power supply to 0 W, and then turn off the target sputtering power supply; (20) Adjust the argon flow controller to bring the flow rate to 0 mL / min, and then turn off the argon switch; (21) Adjust the air pressure in the vacuum chamber back to 1×10 -5 Below Pa; (22) Set up a heat preservation and cooling program to keep the temperature of the vacuum chamber at the temperature of magnetron sputtering, and then let it cool down naturally; (23) After cooling is complete, close the solenoid valve, open the connection switch between the vacuum chamber and the transition chamber, and transfer the sample stage from the vacuum chamber to the transition chamber; (24) Close the connection switch between the vacuum chamber and the transition chamber, open the switch connecting the transition chamber to the outside, and vent the transition chamber. (25) After the venting is completed, close the switch connecting the transition chamber to the outside; (26) Open the transition chamber and remove the sample stage; (27) Close the transition chamber and open the solenoid valve to bring the pressure in the vacuum chamber back to 1×10⁻⁶. -5 Below Pa; (28) Remove the sample from the sample stage to obtain the substrate-loaded antiferromagnetic manganese-iridium intermetallic compound nanofilm.
[0068] Thirdly, the present invention provides the application of substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilms as described in the first aspect, or substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilms prepared by the preparation method described in the second aspect, in the preparation of electrocatalytic materials for oxygen evolution reaction.
[0069] It should be noted that this invention utilizes magnetron sputtering technology to prepare antiferromagnetic manganese-iridium intermetallic compound nanofilms on single-crystal substrates such as MgO. Compared to commercially available Ir / C catalysts, this electrocatalytic material not only significantly reduces the amount of precious metal Ir used but also effectively improves the catalyst's activity and stability. Furthermore, compared to existing manganese-iridium-based electrocatalytic material preparation processes, magnetron sputtering technology offers significant advantages such as strong process controllability, simplified industrial production, and environmental friendliness. Currently, magnetron sputtering equipment is widely used in semiconductor device manufacturing, demonstrating high technological maturity and a variety of equipment models to meet the needs of preparing films of different sizes and types. In addition, the growth temperature of this antiferromagnetic manganese-iridium intermetallic compound nanofilm catalytic material is relatively low, significantly reducing energy consumption during the preparation process. Studies also show that this type of antiferromagnetic manganese-iridium intermetallic compound nanofilm catalyst exhibits low sensitivity to parameters such as surface state, crystallinity, thickness, and substrate type, indicating high intrinsic catalytic activity of both Mn and Ir. Therefore, the material design of this electrocatalytic film offers strong flexibility and freedom. In summary, the development of antiferromagnetic manganese-iridium intermetallic compound nanofilm electrocatalytic materials supported on MgO single-crystal substrates is expected to overcome the key bottlenecks in catalyst activity, stability, and cost of current electrocatalytic water splitting technology, and provide an innovative and feasible solution for its large-scale application.
[0070] Fourthly, the present invention provides an oxygen evolution reaction electrocatalyst material, wherein the oxygen evolution reaction electrocatalyst comprises a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm as described in the first aspect, or a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm prepared by the preparation method described in the second aspect.
[0071] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.
[0072] The following are some of the sources of raw materials:
[0073] Example 1 This embodiment provides a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm, which is prepared by the following steps: (1) Take out a 5 mm × 5 mm × 0.5 mm (100) oriented single crystal MgO substrate and fix the substrate on the sample stage of the magnetron sputtering equipment using silver paste; (2) Place the sample stage with the MgO substrate attached in step (1) on a heating stage with the temperature set to 120 °C and heat for 5 min to dry the silver paste. (3) Open the vacuum chamber of the magnetron sputtering equipment, replace the target material of the magnetron sputtering equipment with MnIr target material, and then close the vacuum chamber and ensure it is sealed; (4) Turn on the cooling water circulation system; (5) Turn on the main power switch of the magnetron sputtering equipment to start the magnetron sputtering equipment; (6) Turn on the mechanical pump switch of the magnetron sputtering equipment to extract the air from the vacuum chamber of the magnetron sputtering and make the air pressure in the vacuum chamber reach 10 Pa. (7) Turn on the molecular pump switch of the magnetron sputtering equipment, open the solenoid valve of the magnetron sputtering equipment, and extract the air from the vacuum chamber of the magnetron sputtering equipment to make the air pressure in the vacuum chamber reach 1×10 -5 Pa; (8) Place the sample stage with the substrate attached, which was fixed in step (3), into the transition chamber of the magnetron sputtering equipment with the substrate side facing down; (9) Close the solenoid valve of the magnetron sputtering equipment, open the connection switch between the mechanical pump and the transition chamber, and use the mechanical pump to extract air from the transition chamber for 10 minutes; (10) Close the connection switch between the mechanical pump and the transition chamber, open the connection switch between the transition chamber and the vacuum chamber, and place the sample stage into the vacuum chamber; (11) Close the connection switch between the transition chamber and the vacuum chamber, and open the solenoid valve to bring the air pressure in the vacuum chamber back to 1×10⁻⁶. -5 Pa; (12) Turn on the heating equipment switch, set the heating program, and raise the temperature of the vacuum chamber to 200 °C at a rate of 10 °C / min, and maintain the temperature at 200 °C; (13) Turn on the argon gas switch and the argon gas flow controller, and control the argon gas flow rate at 25 mL / min; (14) Adjust the air pressure in the vacuum chamber to maintain it at 0.4 Pa; (15) Turn on the sputtering power supply for the target and adjust the sputtering power to 60 W; (16) Close the sample stage baffle to block the sample stage, open the target baffle switch, open the target baffle, and start pre-sputtering for 10 minutes; (17) After the pre-sputtering is completed, open the sample stage baffle and start sputtering. The sputtering time is 10 min. (18) After sputtering is completed, first close the sample stage baffle, then close the target baffle; (19) Adjust the power of the target sputtering power supply to 0 W, and then turn off the target sputtering power supply; (20) Adjust the argon flow controller to bring the flow rate to 0 mL / min, and then turn off the argon switch; (21) Adjust the air pressure in the vacuum chamber back to 1×10-5 Pa; (22) Set up a heat preservation and cooling program to keep the temperature of the vacuum chamber at 200 °C for 30 min, and then let it cool down naturally to 25 °C; (23) After cooling is complete, close the solenoid valve, open the connection switch between the vacuum chamber and the transition chamber, and transfer the sample stage from the vacuum chamber to the transition chamber; (24) Close the connection switch between the vacuum chamber and the transition chamber, open the switch connecting the transition chamber to the outside, and vent the transition chamber for 1 minute; (25) After the venting is completed, close the switch connecting the transition chamber to the outside; (26) Open the transition chamber and remove the sample stage; (27) Close the transition chamber and open the solenoid valve to bring the pressure in the vacuum chamber back to 1×10⁻⁶. -5 Pa; (28) The antiferromagnetic manganese-iridium intermetallic compound nanofilm sample supported on the MgO substrate was removed from the sample stage using a blade to obtain the electrocatalytic material of the antiferromagnetic manganese-iridium intermetallic compound nanofilm supported on the MgO substrate; wherein the antiferromagnetic manganese-iridium intermetallic compound nanofilm is a polycrystalline MnIr film with a thickness of 29.5 nm, wherein the molar ratio of manganese to iridium is 45:55.
[0074] Following the transmission electron microscopy (TEM) testing method, the obtained antiferromagnetic manganese-iridium intermetallic compound nanofilm was characterized by TEM using a JEOL JEM NeoARM200 microscope with spherical aberration correction under an operating accelerating voltage of 200 kV.
[0075] The result is as follows Figure 1 As shown, by Figure 1 It can be concluded that the obtained MgO-based antiferromagnetic manganese-iridium intermetallic compound nanofilm has a polycrystalline structure; Figure 1 From b and 1c, we can see that Mn and Ir elements are uniformly distributed in the thin film; from Figure 1 d、 Figure 1 e Figure 1 As can be seen from f, a family of crystal planes with interplanar spacings of 0.13 nm and 0.21 nm appears in the polycrystalline metal film. This indicates that the present invention can effectively prepare a uniform MnIr polycrystalline metal film supported on a MgO substrate.
[0076] Example 2 This embodiment provides a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm. The difference from Embodiment 1 is that the sputtering parameters in step (17) are adjusted to 6.5 min, so that the thickness of the antiferromagnetic manganese-iridium intermetallic compound nanofilm is adjusted to 20 nm. The other steps are the same as in Embodiment 1.
[0077] Example 3 This embodiment provides a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm. The difference from Embodiment 1 is that the sputtering parameters in step (17) are adjusted to 13 min, so that the thickness of the antiferromagnetic manganese-iridium intermetallic compound nanofilm is adjusted to 40 nm. The other steps are the same as in Embodiment 1.
[0078] Example 4 This embodiment provides a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm. The difference from Embodiment 1 is that the sputtering parameters in step (17) are adjusted to 26 min, so that the thickness of the antiferromagnetic manganese-iridium intermetallic compound nanofilm is adjusted to 80 nm. The other steps are the same as in Embodiment 1.
[0079] Example 5 This embodiment provides a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm. The difference from Embodiment 2 is that the magnesium oxide substrate is replaced with a (100) oriented single crystal SrTiO3 substrate of the same size (5 mm × 5 mm × 0.5 mm). The other steps are the same as in Embodiment 2.
[0080] Example 6 This embodiment provides a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm. The difference from Embodiment 2 is that the magnesium oxide substrate is replaced with a 5 mm × 5 mm × 0.5 mm (100) oriented SrTiO3 substrate doped with 0.7% Nb. The other steps are the same as in Embodiment 2.
[0081] Comparative Example 1 This comparative example provides a substrate-supported metal oxide nanofilm, comprising: a substrate, and a film supported on the surface of the substrate; wherein the substrate is also a 5 mm × 5 mm × 0.5 mm (100) oriented single crystal MgO substrate; the film is a RuO2 metal oxide nanofilm with a thickness of 23.6 nm.
[0082] Comparative Example 2 This comparative example provides a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm, which differs from Example 1 in that the magnesium oxide substrate is replaced with a carbon cloth substrate of the same specifications, while the other steps are the same as in Example 1.
[0083] Comparative Example 3 This comparative example provides a substrate-supported manganese metal nanofilm. The difference from Example 1 is that the MnIr target in step (3) is replaced with a pure Mn target, while the other steps are the same as in Example 1.
[0084] Comparative Example 4 This comparative example provides a substrate-supported iridium metal nanofilm. The difference from Example 1 is that the MnIr target in step (3) is replaced with a pure Ir target, while the other steps are the same as in Example 1.
[0085] Test Example 1 Test samples: Antiferromagnetic manganese-iridium intermetallic compound nanofilms supported on magnesium oxide substrates provided in Examples 1-6, RuO2 metal film provided in Comparative Example 1, antiferromagnetic manganese-iridium intermetallic compound nanofilms supported on carbon substrates provided in Comparative Example 2, manganese metal nanofilms supported on magnesium oxide substrates provided in Comparative Example 3, and iridium metal nanofilms supported on magnesium oxide substrates provided in Comparative Example 4.
[0086] Test method: (1) Electrochemical test: According to the electrochemical linear voltammetry test method, under the condition of scanning speed of 10 mV / s, the above samples were electrochemically tested using the CHI660E electrochemical workstation of Shanghai Chenhua Instrument Co., Ltd. The electrocatalytic activity of catalytic oxygen evolution in O2 saturated 0.1 M KOH solution was determined, with the reference electrode being Ag / AgCl electrode and the counter electrode being graphite electrode; and linear scanning voltammetry curves of different samples were plotted.
[0087] (2) Stability test: According to the chronopotential test method, at a constant 10 mA / cm 2 At a current density of [value missing], the stability of the above samples was tested using a CHI660E electrochemical workstation from Shanghai Chenhua Instrument Co., Ltd. The voltage required for catalytic oxygen evolution in O2-saturated 0.1 M KOH solution was determined, with the reference electrode being an Ag / AgCl electrode and the counter electrode being a graphite electrode; and chronopotential curves of different samples were plotted.
[0088] The specific test results are shown in Table 1: Table 1
[0089] As shown in Table 1, the antiferromagnetic manganese-iridium intermetallic compound nanofilm electrocatalytic material prepared in this invention exhibits superior oxygen evolution reaction (OER) electrocatalytic performance. Compared with existing noble metal catalysts, this material shows significantly higher intrinsic catalytic activity in alkaline media, with a more negative onset potential and lower polarization, indicating that it can drive the water splitting reaction more efficiently and significantly reduce the reaction energy barrier. Simultaneously, the material maintains high voltage stability under long-term constant current operation without significant decay or deactivation, demonstrating excellent structural durability and electrochemical stability. Crucially, this catalytic performance does not rely on stringent interface modulation or special substrate modification, but rather stems from the high active site density and strong corrosion resistance conferred by the optimized intrinsic electronic structure of the Mn-Ir intermetallic compound. Overall, this material balances high activity and strong stability.
[0090] Comparative data from Example 1 and Comparative Example 1 show that the antiferromagnetic manganese-iridium intermetallic compound nanofilm exhibits significantly higher catalytic activity in the oxygen evolution reaction compared to traditional RuO2 noble metal oxide catalysts. Its onset potential is more negative, and its polarization is lower, enabling it to drive the water splitting reaction more efficiently. Furthermore, this material demonstrates excellent electrochemical stability under prolonged constant current operation, without significant degradation. This indicates that the electronic structure optimization of the MnIr intermetallic compound structure has successfully overcome the technical challenge of synergistically improving the activity and stability of existing noble metal catalysts.
[0091] Comparative data from Example 1 and Comparative Example 2 show that the antiferromagnetic manganese-iridium intermetallic compound nanofilm supported on a metal oxide single-crystal substrate exhibits superior catalytic activity and stability in the oxygen evolution reaction compared to the same film supported on a carbon cloth substrate. This indicates that the metal oxide single-crystal substrate possesses a highly ordered atomic arrangement, excellent surface flatness, and good chemical stability, providing an ideal crystal template for the epitaxial growth of the film and promoting the formation of a catalytic interface with a uniform structure and a reasonable distribution of active sites. In contrast, the carbon cloth substrate is prone to structural degradation during high-temperature sputtering, leading to uneven dispersion of active components and poor interfacial contact, thereby affecting catalytic performance.
[0092] Comparative data from Example 1 and Comparative Example 3 show that the manganese-iridium intermetallic compound nanofilm exhibits significantly higher catalytic activity and stability in the oxygen evolution reaction compared to pure manganese metal nanofilms. This indicates that combining manganese with the noble metal iridium to form an intermetallic compound structure can effectively regulate the electronic structure, optimize the adsorption behavior of oxygen-containing reaction intermediates, and reduce the reaction overpotential. Simultaneously, the introduction of iridium enhances interatomic interactions, inhibits the dissolution and structural degradation of the active component, and achieves a synergistic improvement in activity and stability. Pure manganese-based materials, due to their poor intrinsic conductivity and low active site density, are insufficient to meet the requirements of high-performance electrocatalysis.
[0093] Comparative data from Example 1 and Comparative Example 4 show that the manganese-iridium intermetallic compound nanofilm exhibits superior catalytic activity and significantly higher stability in the oxygen evolution reaction compared to pure iridium nanofilm. This indicates that combining the noble metal iridium with the transition metal manganese to form an intermetallic compound can optimize catalytic performance through electronic structure regulation, while significantly reducing the amount of noble metal used, achieving a balance between cost and performance. Furthermore, the introduction of manganese effectively inhibits the dissolution and aggregation of iridium, significantly enhancing the structural durability of the material. While pure iridium-based materials possess certain activity, their stability is insufficient and their cost is high, making them unsuitable for practical applications.
[0094] Figure 2 Linear scan voltammetric curves of the antiferromagnetic manganese-iridium intermetallic compound nanofilms and RuO2 metal oxide nanofilms obtained in Example 1 and Comparative Example 1 are shown. Figure 2 It can be seen that at 1 mA / cm 2 At a given current density, the oxygen evolution overpotential of the antiferromagnetic manganese-iridium intermetallic compound nanofilm is only 294 mV, while that of the RuO2 metal oxide nanofilm is 390 mV. Therefore, the antiferromagnetic manganese-iridium intermetallic compound nanofilm exhibits higher electrocatalytic oxygen evolution activity than the RuO2 metal oxide nanofilm. This demonstrates that the antiferromagnetic manganese-iridium intermetallic compound nanofilm material prepared in this invention is a functional catalytic material with ultra-high OER activity.
[0095] Figure 3 The figures show the chronopotential curves of the antiferromagnetic manganese-iridium intermetallic compound nanofilms and RuO2 metal oxide nanofilms obtained in Example 1 and Comparative Example 1. Figure 3 It can be seen that the antiferromagnetic manganese-iridium intermetallic compound nanofilm maintains 10 mA / cm. 2 The overpotential time at the current density was 10⁹ h, while the RuO₂ metal oxide nanofilm maintained 10 mA / cm². 2 The overpotential time at the current density was 4 h, and the antiferromagnetic manganese-iridium intermetallic compound nanofilm exhibited superior electrocatalytic oxygen evolution stability compared to the RuO2 metal oxide nanofilm. This indicates that the antiferromagnetic manganese-iridium intermetallic compound nanofilm material prepared in this invention is a functional catalytic material with excellent catalytic OER stability.
[0096] Figure 4 Linear scanning voltammetry (LSV) curves of antiferromagnetic manganese-iridium intermetallic nanofilms supported on 5 mm × 5 mm × 0.5 mm (100) oriented single-crystal MgO substrates with thicknesses of 20 nm, 40 nm, and 80 nm, respectively, obtained in Examples 2-4, are shown. Figure 4 It can be seen that at 1 mA / cm 2At the given current density, the oxygen evolution overpotentials of the antiferromagnetic manganese-iridium intermetallic compound nanofilms with three different thickness loads were 322 mV, 330 mV, and 311 mV, respectively. The difference in overpotential among the three was small, indicating that the antiferromagnetic manganese-iridium intermetallic compound nanofilm material prepared in this invention is not sensitive to the parameter of film thickness.
[0097] Figure 5 Linear sweep voltammetry curves of antiferromagnetic manganese-iridium intermetallic nanofilms supported on (100) oriented single-crystal MgO substrates (5 mm × 5 mm × 0.5 mm), (100) oriented single-crystal SrTiO3 substrates (5 mm × 5 mm × 0.5 mm), and (100) oriented single-crystal SrTiO3 substrates (0.7% Nb) doped with 0.7% Nb, respectively, are shown in Examples 1 and 5-6. Figure 5 It can be seen that at 1 mA / cm 2 At the given current density, the oxygen evolution overpotentials of the antiferromagnetic manganese-iridium intermetallic compound nanofilms with three different substrate loads were 294 mV, 301 mV, and 315 mV, respectively. The difference in overpotential among the three was small, indicating that the antiferromagnetic manganese-iridium intermetallic compound nanofilm material prepared in this invention is not sensitive to the substrate type parameter.
[0098] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm, characterized in that, Includes: a substrate, and an antiferromagnetic manganese-iridium intermetallic compound nanofilm formed by magnetron sputtering and loaded on the surface of the substrate; The substrate includes any one of magnesium oxide substrate, strontium titanate substrate, and niobium-doped strontium titanate substrate.
2. The substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm according to claim 1, characterized in that, The substrate is a (100) oriented single-crystal magnesium oxide substrate; Preferably, the substrate has a length of 3 to 10 mm, a width of 3 to 10 mm, and a thickness of 0.3 to 0.7 mm.
3. The substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm according to claim 1, characterized in that, The antiferromagnetic manganese-iridium intermetallic compound nanofilm has a polycrystalline structure. Preferably, the thickness of the antiferromagnetic manganese-iridium intermetallic compound nanofilm is 10~100 nm; Preferably, the molar ratio of manganese to iridium in the antiferromagnetic manganese-iridium intermetallic compound nanofilm is (45~50):(50~55).
4. The substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm according to claim 1, characterized in that, The antiferromagnetic manganese-iridium intermetallic compound nanofilm has a grain size of 3-8 nm; the interplanar spacing includes a family of crystal planes with d1 of 0.18-0.23 nm and d2 of 0.10-0.15 nm.
5. A method for preparing an antiferromagnetic manganese-iridium intermetallic compound nanofilm supported on a substrate according to any one of claims 1 to 4, characterized in that, The preparation method includes: An antiferromagnetic manganese-iridium intermetallic compound nanofilm was deposited on the surface of the substrate by magnetron sputtering, using a manganese-iridium intermetallic compound as the target material, to obtain an antiferromagnetic manganese-iridium intermetallic compound nanofilm loaded on the substrate.
6. The method for preparing substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilms according to claim 5, characterized in that, The parameters for the magnetron sputtering deposition include: temperature of 195-205 °C; argon flow rate of 20-30 mL / min; chamber pressure of 0.3-0.5 Pa; sputtering power of 55-65 W; and sputtering time of 5-40 min.
7. The method for preparing substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilms according to claim 5 or 6, characterized in that, The process before deposition also includes pre-sputtering of the target material; wherein the parameters for pre-sputtering include: temperature of 195~205 °C; argon flow rate of 20~30 mL / min; chamber pressure of 0.3~0.5 Pa; sputtering power of 55~65 W; and sputtering time of 10~20 min.
8. The method for preparing substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilms according to claim 5 or 5, characterized in that, The deposition process includes a heat preservation treatment; wherein the temperature of the heat preservation treatment is 195~205 °C; and the heat preservation treatment time is 30~40 min.
9. The application of a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm according to any one of claims 1 to 4, or a substrate-supported antiferromagnetic manganese-iridium intermetallic compound nanofilm prepared by the preparation method according to any one of claims 5 to 8, in the preparation of electrocatalytic materials for oxygen evolution reaction.
10. An electrocatalytic material for the oxygen evolution reaction, characterized in that, The oxygen evolution reaction electrocatalyst comprises an antiferromagnetic manganese-iridium intermetallic compound nanofilm supported on a substrate as described in any one of claims 1 to 4, or an antiferromagnetic manganese-iridium intermetallic compound nanofilm supported on a substrate prepared by the preparation method described in any one of claims 5 to 8.