A RuO with oxygen vacancies x Thin film catalysts, their preparation methods and applications

Abstract

This invention belongs to the field of catalytic oxygen evolution technology, specifically relating to a RuO₂ with oxygen vacancies. x Thin-film catalysts, their preparation methods, and applications. RuO₂ was obtained by magnetron sputtering on a substrate using an oxygen-containing inert gas at a flow rate of 20–40 sccm and an oxygen flow rate of 0.1–5 sccm. x Thin film catalyst, wherein RuO x The crystal plane in the thin-film catalyst is the RuO2 (101) crystal plane. This invention utilizes magnetron sputtering deposition technology to precisely control the oxygen partial pressure to prepare RuO2 catalysts with different oxygen vacancy concentrations. x Catalysts can effectively balance the optimal oxygen vacancy concentration between the activity and stability of the catalyst, provide more active sites while avoiding lattice collapse, regulate the d-band center to change the adsorption energy of key intermediates, optimize the reaction path, significantly improve catalytic performance, and prepare films with high purity, density, uniformity, strong adhesion and easy reproducibility.

Description

Technical Field

[0001] This invention belongs to the field of catalytic oxygen evolution technology, specifically relating to a RuO₂ with oxygen vacancies. x Thin film catalysts, their preparation methods, and applications. Background Technology

[0002] The synthesis of basic chemicals or fuel feedstocks using renewable and clean energy through electrochemical methods is demonstrating significant environmental advantages and economic potential, playing a crucial role in addressing climate change and improving environmental quality. This approach not only reduces dependence on fossil fuels but also substantially reduces greenhouse gas emissions, driving the global transition to a low-carbon economy. Various electrochemical technologies have attracted attention in academia and industry, such as the hydrogen evolution reaction (HER) via water splitting, the reduction reaction (CO2 / CORR) to convert carbon dioxide or carbon monoxide into carbon-containing chemicals and fuels, the oxygen reduction reaction (ORR) to produce hydrogen peroxide (H2O2), and the nitrogen reduction reaction (NRR) to synthesize ammonia. These half-cell reduction reactions have become a focus of research because they can directly generate the desired products. However, most of these cathodic reactions must be combined with the oxygen evolution reaction (OER) at the anode to provide protons and achieve charge balance. OER requires only water as a reactant, giving it a greater advantage in large-scale electrolysis compared to other anodic reactions. Therefore, from the long-term development perspective of electrochemical energy conversion, electrocatalytic OER is a core component and key support for various electrochemical technologies.

[0003] Alkaline water electrolysis technology has application potential due to its low catalyst cost and high stability, but its inherent defects, such as high ohmic impedance, slow reaction kinetics, and low current density, make it difficult to meet the technical requirements of large-scale dynamic energy systems. In contrast, proton exchange membrane electrolysis (PEMWE) technology demonstrates significant advantages for industrial application due to its compact system design, low ohmic loss, high current density, and ultra-high purity hydrogen output. Over the past decade, with the increasing demand for large-scale hydrogen production from renewable energy sources, PEMWE technology research has shown an exponential growth trend. Its core breakthrough stems from the highly efficient conduction mechanism of the proton exchange membrane, a characteristic that not only significantly reduces system impedance but also enables stable operation within a certain voltage range. Crucially, PEMWE, through its millisecond-level dynamic response characteristics, deeply couples with intermittent renewable energy sources (such as wind and solar power), providing technical support for the storage and conversion of megawatt-scale renewable energy. However, the irreversible dissolution and lattice oxidation of the anode catalyst under strongly acidic (pH < 1.5) and high-potential (> 1.8 V vs. RHE) conditions lead to electrode activity decay and membrane electrode assembly (MEA) interface failure, severely limiting system lifespan. Overcoming these technical bottlenecks is crucial for the industrial application of PEMWE and the upgrading of the global hydrogen energy industry chain.

[0004] Currently, OER catalysts are usually synthesized using wet chemical methods and coated onto the electrode surface. This method has drawbacks such as poor adhesion between the catalyst and the electrode, uneven film thickness control, and easy contamination. Furthermore, it cannot precisely control the structure and composition to achieve better catalytic activity. Summary of the Invention

[0005] The purpose of this invention is to provide a RuO with oxygen vacancies. x Thin-film catalysts, their preparation methods, and applications: Precise control of oxygen partial pressure using magnetron sputtering deposition technology to prepare RuO₂ with varying oxygen vacancy concentrations. x The optimal oxygen vacancy concentration can effectively balance the activity and stability of the catalyst, resulting in films with high purity, density, uniformity, strong adhesion, and easily reproducible processes. By rationally controlling oxygen vacancies to provide more active sites while avoiding lattice collapse, and by regulating the d-band centers to change the adsorption energy for key intermediates, the reaction pathway can be optimized, significantly improving catalytic performance.

[0006] To achieve the above objectives, the specific technical solution provided by the present invention is as follows: The first objective of this invention is to provide a RuO with oxygen vacancies. x The preparation method of thin-film catalyst includes the following steps: Ruthenium target sputtering reaction was performed on the substrate using magnetron sputtering, with an inert gas containing oxygen at a flow rate of 20 sccm to 40 sccm and an oxygen flow rate of 0.1 sccm to 5 sccm, to deposit RuO. x Thin film catalyst, wherein RuO x The crystal plane in the thin film catalyst is the RuO2 (101) crystal plane.

[0007] Furthermore, during the magnetron sputtering process, the ruthenium target uses an RF power supply with a sputtering power of 60W to 150W and a deposition time of 10min to 40min.

[0008] Furthermore, during the magnetron sputtering process, the background vacuum level is 5 × 10⁻⁶. -4 Pa~6×10 - 4 Pa, working air pressure is 0.2Pa~1.0Pa.

[0009] Furthermore, prior to magnetron sputtering, the substrate is subjected to glow discharge sputtering cleaning, and the gas pressure is evacuated to below 5 × 10⁻⁶. -4 After Pa, argon gas is introduced and the argon gas pressure is controlled at 0.4 Pa to 1.6 Pa. A bias voltage of -300 V to 500 V is applied to the substrate and the glow discharge cleaning time is 10 min to 20 min.

[0010] Furthermore, the purity of the ruthenium target is >99.99%.

[0011] Furthermore, the substrate can be a silicon wafer, titanium felt, or carbon paper.

[0012] A second objective of this invention is to provide a RuO with oxygen vacancies. x The thin-film catalyst was prepared using the method described above.

[0013] A third objective of this invention is to provide the aforementioned RuO with oxygen vacancies. x Application of thin-film catalysts in oxygen evolution through water electrolysis.

[0014] Furthermore, with RuO x The thin-film catalyst serves as the working electrode, and sulfuric acid is used as the electrolyte to carry out the electrochemical catalytic oxygen evolution reaction.

[0015] Furthermore, the concentration of sulfuric acid is 0.5 mol / L to 1 mol / L.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention achieves the control of RuO2 by adjusting the oxygen flow rate to change the oxygen partial pressure. x The oxygen vacancy concentration of thin-film catalysts can be regulated. By rationally controlling oxygen vacancies, more active sites are provided while avoiding lattice collapse. The adsorption energy of key intermediates is altered by controlling the d-band center, optimizing the reaction pathway, and significantly improving catalytic performance. Furthermore, the oxygen vacancy concentration of RuOx thin-film catalysts can be graded and controlled by increasing oxygen partial pressure. Compared to traditional RuO2, the presence of oxygen vacancies alters the coordination environment and electronic states of surrounding metal ions, thereby controlling the adsorption energy of key intermediates, optimizing the reaction pathway, and lowering the reaction energy barrier. Precise control of composition and structure is achieved through magnetron sputtering technology. High-energy particle bombardment or non-equilibrium growth conditions can introduce point defects into the crystal, significantly increasing the number of active sites and yielding RuO2. x The thin-film catalyst exhibits advantages such as dense and uniform deposition, high purity, and strong adhesion. Furthermore, its preparation process is simple, low-cost, and pollution-free, demonstrating good chemical activity and stability, thus maintaining its catalytic performance. This stability helps extend the catalyst's lifespan and provides long-term stable catalytic performance. Attached Figure Description

[0017] Figure 1 RuO prepared in Example 1 of this invention x -0.1 Microscopic scanning electron microscope image of the thin film catalyst.

[0018] Figure 2 RuO prepared in Examples 1 to 3 of this invention x X-ray diffraction pattern of thin-film catalyst.

[0019] Figure 3 RuO prepared in Examples 1 to 3 of this invention x X-ray photoelectron spectroscopy (XPS) image of a thin-film catalyst. Figure 3 In the diagram, a is the full spectrum and b is the O 1s spectrum.

[0020] Figure 4 RuO prepared in Example 4 of this invention x Scanning electron microscope image of the cross-section of the thin-film catalyst.

[0021] Figure 5 RuO prepared in Examples 1 to 3 of this invention x Linear voltammetric scans of the thin-film catalyst and the catalysts prepared in Comparative Examples 1 to 2.

[0022] Figure 6 RuO prepared in Example 1 of this invention x -0.1 Thin film catalyst at 10 mA / cm 2 The potential-time stability test curves were obtained under the specified current density. Detailed Implementation

[0023] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the present invention will be further described below in conjunction with specific embodiments and accompanying drawings. However, the embodiments described are not intended to limit the present invention.

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0025] The trade-off between catalyst activity and stability has prompted research to focus on multi-scale synergistic optimization strategies: atomically controlling the concentration of oxygen vacancies in RuO2 to provide more active sites, and adjusting the adsorption energy for key intermediates in OER to lower the reaction energy barrier and enhance intrinsic activity. The presence of oxygen vacancies makes Ru atoms coordinating unsaturated, enhancing the adsorption capacity for key intermediates while generating more active sites. However, excessively high oxygen vacancy concentrations can lead to over-oxidation of surrounding Ru atoms, accelerating material dissolution. How to select the oxygen vacancy concentration to regulate the d-band center of Ru and adjust the catalyst surface's adsorption capacity for OER reaction intermediates (…) * O, * OH, *By leveraging the adsorption energy of OOH, the contradiction between activity and stability can be balanced, thereby improving catalytic performance. This provides an important approach to overcoming the bottleneck of the trade-off between activity and stability in PEMWE anode catalysts. This multi-scale synergistic optimization strategy, starting from the atomic scale, is expected to open up new paths for designing anode materials that combine high catalytic efficiency with long-term operational stability, and promote the large-scale application of PEMWE technology in the field of renewable energy hydrogen production.

[0026] Based on this, the present invention utilizes magnetron sputtering with oxygen-passing reactive sputtering to precisely control the oxygen partial pressure and prepare RuO with different oxygen vacancy concentrations. x The catalyst was developed to achieve an optimal oxygen vacancy concentration that effectively balances its activity and stability. Specifically:

[0027] A RuO with oxygen vacancies x The preparation method of thin-film catalyst includes the following steps: S1. Place the substrate in the vacuum chamber of the magnetron sputtering equipment, and install the ruthenium target on the target position in the vacuum chamber. The purity of the ruthenium target exceeds 99.99%.

[0028] S2. Perform reverse sputtering cleaning on the substrate. Reverse sputtering cleaning is performed using glow discharge sputtering. The gas pressure is evacuated until it is below 5 × 10⁻⁶. -4 After Pa, argon gas is introduced and the argon gas pressure is controlled at 0.4 Pa to 1.6 Pa. A bias voltage of -300 V to 500 V is applied to the substrate and the glow discharge cleaning time is 10 min to 20 min.

[0029] S3. Argon and oxygen are introduced into the vacuum chamber, with an argon flow rate of 20 sccm to 40 sccm and an oxygen flow rate of 0.1 sccm to 5 sccm. Ruthenium target sputtering is performed on the substrate using magnetron sputtering, with a base vacuum of 5 × 10⁻⁶. -4 Pa~6×10 -4 The working gas pressure is 0.2 Pa to 1.0 Pa, the ruthenium target uses an RF power supply, the ruthenium target sputtering power is 60 W to 150 W, the deposition time is 10 min to 40 min, and RuO is deposited. x Thin film catalyst, wherein RuO x The crystal plane in the thin film catalyst is the RuO2 (101) crystal plane.

[0030] This invention achieves the control of RuO2 by adjusting the oxygen flow rate to change the oxygen partial pressure. x The oxygen vacancy concentration of thin-film catalysts can be regulated to provide more active sites while avoiding lattice collapse. By controlling the d-band centers to alter the adsorption energy for key intermediates, the reaction pathway can be optimized, significantly improving catalytic performance. Furthermore, the adsorption of RuO can be increased with increasing oxygen partial pressure. xThe oxygen vacancy concentration in thin-film catalysts can be controlled. Compared to traditional RuO2, the presence of oxygen vacancies alters the coordination environment and electronic states of surrounding metal ions, thereby regulating the adsorption energy of key intermediates, optimizing the reaction pathway, and lowering the reaction energy barrier. Precise control of composition and structure can be achieved through magnetron sputtering technology. High-energy particle bombardment or non-equilibrium growth conditions can introduce point defects into the crystal, significantly increasing the number of active sites and yielding RuO2. x The thin-film catalyst exhibits advantages such as dense and uniform deposition, high purity, and strong adhesion. Furthermore, its preparation process is simple, low-cost, and pollution-free, demonstrating good chemical activity and stability, thus maintaining its catalytic performance. This stability helps extend the catalyst's lifespan and provides long-term stable catalytic performance.

[0031] In this invention, RuO x The crystal facet in the thin film catalyst is the RuO2 (101) crystal facet. By controlling the crystal facet in the catalyst, the catalytic activity and stability can be balanced. The electronic structure of the RuO2 (101) crystal facet causes its binding energy for oxygen-containing intermediates to be in a different range than that of the RuO2 (100) and (110) crystal facests. The rate-determining steps in the reaction are also different. However, through surface modification, it is easier to control the adsorption energy of the (101) crystal facet for intermediates and optimize the reaction pathway to a more kinetic and structurally stable one.

[0032] In some embodiments, the substrate includes, but is not limited to, commercially polished silicon wafers, titanium felt, or carbon paper. Before sputtering, the substrate needs to be surface cleaned to remove surface impurities. The substrate surface cleaning method is as follows: the substrate is placed in acetone solution and ultrasonically cleaned at 80W power for 30 minutes, then placed in ethanol and ultrasonically cleaned at 80W power for 30 minutes, then placed in deionized water and ultrasonically cleaned at 80W power for 30 minutes, and finally the deionized water on the substrate surface is dried in an oven (45°C for 1 hour).

[0033] The present invention also provides a RuO with oxygen vacancies. x Thin-film catalysts utilize oxygen vacancies to provide more active sites for electrochemical reactions, enhancing reaction activity. They exhibit good chemical activity and stability, maintaining their catalytic performance. In water electrolysis and oxygen evolution reaction (OER), this helps extend the catalyst's lifespan and provides long-term stable catalytic performance. The introduction of oxygen vacancies can reconstruct the local coordination structure of surrounding metal ions and modulate their electronic states, thereby optimizing the adsorption free energy for key reaction intermediates, promoting more efficient reaction pathways, and significantly reducing the reaction energy barrier. The method for the water electrolysis and OER reaction involves using a calomel electrode as the reference electrode, a carbon rod as the counter electrode, and RuO2 as the reactant electrode. x The thin-film catalyst forms a three-electrode system with the working electrode, which is connected to an electrochemical detection device. Electrochemical reactions are carried out using 0.5 mol / L to 1 mol / L H2SO4 as the electrolyte.

[0034] The following specific examples will provide further explanation.

[0035] Example 1 A RuO with oxygen vacancies x The preparation method of thin-film catalyst includes the following steps: S1. Place the titanium felt substrate in acetone solution and ultrasonically clean it for 30 minutes at 80W power. Then place it in ethanol and ultrasonically clean it for 30 minutes at 80W power. Next, place it in deionized water and ultrasonically clean it for 30 minutes at 80W power. Finally, dry the deionized water on the surface of the titanium felt in an oven (dry at 45℃ for 1 hour). S2. Install the treated titanium felt on the workpiece gantry inside the vacuum chamber of the magnetron sputtering equipment, and install the ruthenium target on the target position inside the vacuum chamber. The ruthenium target has a purity of over 99.99%.

[0036] S3. Perform glow discharge sputtering cleaning on the titanium felt deposition surface. The glow discharge sputtering cleaning method is as follows: Evacuate the magnetron sputtering vacuum chamber to a pressure below 5 × 10⁻⁶. -4 After Pa, argon gas was introduced and the pressure was controlled at 0.8 Pa. A bias voltage of -300V was applied to the substrate, and glow discharge cleaning was performed for 15 min. Then, argon and oxygen were introduced into the vacuum chamber at a flow rate of 20 sccm and 0.1 sccm, respectively, and the working pressure was controlled at 0.5 Pa. The ruthenium target was treated with an RF power supply with a power controlled at 60W, and the deposition time was 30 min, yielding RuO. x Thin-film catalyst, named RuO x -0.1 Thin film catalyst.

[0037] Example 2 A RuO with oxygen vacancies x The preparation method of thin-film catalyst includes the following steps: S1. Place the titanium felt substrate in acetone solution and ultrasonically clean it for 30 minutes at 80W power. Then place it in ethanol and ultrasonically clean it for 30 minutes at 80W power. Next, place it in deionized water and ultrasonically clean it for 30 minutes at 80W power. Finally, dry the deionized water on the surface of the titanium felt in an oven (dry at 45℃ for 1 hour). S2. Install the treated titanium felt on the workpiece gantry inside the vacuum chamber of the magnetron sputtering equipment, and install the ruthenium target on the target position inside the vacuum chamber. The ruthenium target has a purity of over 99.99%.

[0038] S3. Perform glow discharge sputtering cleaning on the titanium felt deposition surface. The glow discharge sputtering cleaning method is as follows: Evacuate the magnetron sputtering vacuum chamber to a pressure below 5 × 10⁻⁶. -4After Pa, argon gas was introduced and the pressure was controlled at 0.8 Pa. A bias voltage of -300V was applied to the substrate, and glow discharge cleaning was performed for 15 min. Then, argon and oxygen were introduced into the vacuum chamber at a flow rate of 20 sccm and 0.2 sccm, respectively, and the working pressure was controlled at 0.5 Pa. The ruthenium target was treated with an RF power supply with a power controlled at 60W, and the deposition time was 30 min, yielding RuO. x Thin-film catalyst, named RuO x -0.2 Thin film catalyst.

[0039] Example 3 A RuO with oxygen vacancies x The preparation method of thin-film catalyst includes the following steps: S1. Place the titanium felt substrate in acetone solution and ultrasonically clean it for 30 minutes at 80W power. Then place it in ethanol and ultrasonically clean it for 30 minutes at 80W power. Next, place it in deionized water and ultrasonically clean it for 30 minutes at 80W power. Finally, dry the deionized water on the surface of the titanium felt in an oven (dry at 45℃ for 1 hour). S2. Install the treated titanium felt on the workpiece gantry inside the vacuum chamber of the magnetron sputtering equipment, and install the ruthenium target on the target position inside the vacuum chamber. The ruthenium target has a purity of over 99.99%.

[0040] S3. Perform glow discharge sputtering cleaning on the titanium felt deposition surface. The glow discharge sputtering cleaning method is as follows: Evacuate the magnetron sputtering vacuum chamber to a pressure below 5 × 10⁻⁶. -4 After Pa, argon gas was introduced and the pressure was controlled at 0.8 Pa. A bias voltage of -300V was applied to the substrate, and glow discharge cleaning was performed for 15 min. Then, argon and oxygen were introduced into the vacuum chamber at a flow rate of 20 sccm and 0.3 sccm, respectively, and the working pressure was controlled at 0.5 Pa. The ruthenium target was treated with an RF power supply with a power controlled at 60W, and the deposition time was 30 min, yielding RuO. x Thin-film catalyst, named RuO x -0.3 Thin film catalyst.

[0041] Example 4 A RuO with oxygen vacancies x The preparation method of thin-film catalyst includes the following steps: S1. Place the single-polished silicon wafer substrate in acetone solution and ultrasonically clean it at 80W power for 30 minutes. Then place it in ethanol and ultrasonically clean it at 80W power for 30 minutes. Next, place it in deionized water and ultrasonically clean it at 80W power for 30 minutes. Finally, dry the deionized water on the surface of the single-polished silicon wafer in an oven (45℃ for 1 hour). S2. The processed single-spray silicon wafer is installed on the workpiece gantry in the vacuum chamber of the magnetron sputtering equipment, and the ruthenium target is installed on the target position in the vacuum chamber. The purity of the ruthenium target exceeds 99.99%.

[0042] S3. Perform glow discharge sputtering cleaning on the deposition surface of the single-layer polished silicon wafer. The glow discharge sputtering cleaning method is as follows: evacuate the magnetron sputtering vacuum chamber to a pressure below 5 × 10⁻⁶. -4 After Pa, argon gas was introduced and the pressure was controlled at 0.8 Pa. A bias voltage of -300V was applied to the substrate, and glow discharge cleaning was performed for 15 min. Then, argon and oxygen were introduced into the vacuum chamber at a flow rate of 20 sccm and 0.1 sccm, respectively, and the working pressure was controlled at 0.5 Pa. The ruthenium target was treated with an RF power supply with a power controlled at 60W, and the deposition time was 30 min, yielding RuO. x Thin film catalysts.

[0043] Comparative Example 1 A method for preparing a RuO2 thin-film catalyst includes the following steps: S1. Place the titanium felt substrate in acetone solution and ultrasonically clean it for 30 minutes at 80W power. Then place it in ethanol and ultrasonically clean it for 30 minutes at 80W power. Next, place it in deionized water and ultrasonically clean it for 30 minutes at 80W power. Finally, dry the deionized water on the surface of the titanium felt in an oven (dry at 45℃ for 1 hour).

[0044] S2. Install the treated titanium felt on the workpiece gantry inside the vacuum chamber of the magnetron sputtering equipment, and install the ruthenium target on the target position inside the vacuum chamber. The ruthenium target has a purity of over 99.99%.

[0045] S3. Perform glow discharge sputtering cleaning on the titanium felt deposition surface. The glow discharge sputtering cleaning method is as follows: Evacuate the magnetron sputtering vacuum chamber to a pressure below 5 × 10⁻⁶. -4 After Pa, argon gas was introduced and the pressure was controlled at 0.8 Pa. A bias voltage of -300 V was applied to the substrate, and glow discharge cleaning was performed for 15 min. Then, argon and oxygen were introduced into the vacuum chamber. The argon gas flow rate was 20 sccm, the oxygen gas flow rate was 1 sccm, and the working pressure was controlled at 0.5 Pa. The ruthenium target was powered by an RF power supply with a power controlled at 100 W. The deposition time was 20 min. The prepared sample was heated to 300 °C in air at a heating rate of 5 °C / min, annealed for 3 h, and cooled to room temperature to obtain the RuO2 thin film catalyst.

[0046] Comparative Example 2 A method for preparing a titanium felt catalyst includes the following steps: The titanium felt substrate was ultrasonically cleaned in acetone solution at 80W for 30 min, then in ethanol at 80W for 30 min, and then in deionized water at 80W for 30 min. Finally, the deionized water on the surface of the titanium felt was dried in an oven (45℃ for 1 h) to obtain the titanium felt catalyst, named Ti.

[0047] The RuO prepared in Examples 1 to 4 x The thin-film catalyst underwent structural testing, and the results are shown below.

[0048] Figure 1 RuO prepared in Example 1 of this invention x -0.1 microscopic scanning electron microscope image of the thin-film catalyst. (See image for reference.) Figure 1 As shown, the figure in the upper right corner is a macroscopic morphology diagram. The macroscopic morphology basically maintains the original morphology of the titanium felt, and the film layer is uniformly distributed on the substrate surface.

[0049] Figure 2 RuO prepared in Examples 1 to 3 of this invention x X-ray diffraction pattern of a thin-film catalyst. (e.g.) Figure 2 The diffraction peaks obtained by phase analysis using X-ray diffraction (XRD) are shown. This series of RuO x The preferred orientation of the sample crystal plane is RuO2 (101) crystal plane.

[0050] Figure 3 RuO prepared in Examples 1 to 3 of this invention x X-ray photoelectron spectroscopy (XPS) image of a thin-film catalyst. Figure 3 In the diagram, a is the full spectrum, and b is the O 1s spectrum. For example... Figure 3 As shown in Figure (a), RuO prepared in Examples 1 to 3 x The XPS full spectrum of the thin-film catalysts all showed clear peaks corresponding to Ru and O. To accurately determine the RuO content... x The oxygen vacancy concentration of the sample, for RuO prepared in Examples 1 to 3 x Fine spectral analysis of the O 1s of the thin-film catalyst was performed, such as... Figure 3 As shown in (b), peak fitting reveals that each RuOx sample contains peaks corresponding to Ru-O bonds and oxygen vacancies. The peak area ratio of oxygen vacancies is calculated to obtain the RuO... x -0.1、RuO x -0.2 and RuO xThe oxygen vacancy concentrations in the -0.3 samples were 12.76%, 18.81%, and 24.2%, respectively, indicating that the oxygen vacancy concentration increased with increasing oxygen partial pressure. The presence of oxygen vacancies, as a surface defect, can provide more active sites for catalytic reactions. However, excessive oxygen vacancy concentration can cause lattice collapse of RuO2, leading to rapid catalyst deactivation and poor stability. Therefore, it is necessary to rationally control the oxygen vacancy concentration in RuO2. x A certain oxygen vacancy concentration can balance the contradiction between activity and stability, which is more conducive to large-scale industrial use.

[0051] Figure 4 RuO prepared in Example 4 of this invention x Scanning electron microscope (SEM) image of the cross-section of the thin-film catalyst. (e.g.) Figure 4 As shown, the film thickness is 153 nm, and the overall thickness is uniform.

[0052] The RuO prepared in Examples 1 to 3 x The thin-film catalyst and the catalysts prepared in Comparative Examples 1 and 2 were used in the oxygen evolution reaction of water electrolysis. The method for the oxygen evolution reaction of water electrolysis was as follows: a three-electrode system was formed by using a calomel electrode as a reference electrode, a carbon rod as a counter electrode, and a working electrode, connected to an electrochemical detection device, and using 0.5 mol / L H2SO4 as the electrolyte to carry out the electrochemical reaction. The working electrode was selected from RuO2 prepared in Example 1. x -0.1 catalyst, RuO prepared in Example 2 x -0.2 catalyst, RuO prepared in Example 3 x -0.3 catalyst, RuO2 catalyst prepared in Comparative Example 1 and titanium felt in Comparative Example 2.

[0053] Figure 5 RuO prepared in Examples 1 to 3 of this invention x Linear voltammetric scan (LSV) curves of the thin-film catalyst and the catalysts prepared in Comparative Examples 1 to 2. Figure 5 As shown, the titanium felt substrate does not participate in the catalytic reaction, and RuO with oxygen vacancies is obtained by magnetron sputtering. x The catalyst effectively enhances the catalytic activity of ruthenium-based catalysts in the electrolysis of water for oxygen evolution. The introduction of oxygen vacancies can reconstruct the local coordination structure of surrounding metal ions and modulate their electronic states, thereby optimizing the adsorption free energy for key reaction intermediates, promoting a more efficient reaction pathway, and significantly reducing the reaction energy barrier. Furthermore, during the preparation process, bombardment by high-energy particles or non-equilibrium growth conditions can introduce point defects into the crystal, significantly increasing the number of active sites, making it a high-performance catalyst for water electrolysis and oxygen evolution.

[0054] Examples 1 to 4 of this invention all yielded RuO with excellent catalytic performance. xThin-film catalyst, the RuO prepared in Example 1 below. x Taking a 0.1-millimeter thin-film catalyst as an example, further research was conducted to illustrate the RuO... x Stability of thin-film catalysts. The method for the oxygen evolution reaction in water electrolysis using a three-electrode workstation is as follows: using a calomel electrode as the reference electrode, a carbon rod as the counter electrode, and RuO2 as the electrode. x A thin-film catalyst of -0.1 is used as the working electrode to form a three-electrode system, which is connected to an electrochemical detection device and the reaction is carried out using 0.5 mol / L H2SO4 as the electrolyte. Figure 6 RuO prepared in Example 1 of this invention x -0.1 Thin film catalyst at 10 mA / cm 2 The potential-time stability test curves under current density are shown. Figure 6 As shown, the catalyst exhibits both excellent intrinsic activity and structural stability in the tests, ensuring its long-lasting catalytic performance and lifespan under harsh electrochemical conditions.

[0055] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the invention.

[0056] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A RuO group with oxygen vacancies x A method for preparing a thin-film catalyst, characterized in that, Includes the following steps: Ruthenium target sputtering reaction was performed on the substrate using magnetron sputtering, with an inert gas containing oxygen at a flow rate of 20 sccm to 40 sccm and an oxygen flow rate of 0.1 sccm to 5 sccm, to deposit RuO. x Thin film catalyst, wherein RuO x The crystal plane in the thin film catalyst is the RuO2 (101) crystal plane.

2. The RuO with oxygen vacancies according to claim 1 x A method for preparing a thin-film catalyst, characterized in that, During magnetron sputtering, the ruthenium target is powered by an RF power supply, with a sputtering power of 60W to 150W and a deposition time of 10min to 40min.

3. The RuO with oxygen vacancies according to claim 1 x A method for preparing a thin-film catalyst, characterized in that, During magnetron sputtering, the background vacuum level is 5×10⁻⁶. -4 Pa~6×10 -4 Pa, working air pressure is 0.2Pa~1.0Pa.

4. The RuO with oxygen vacancies according to claim 1 x A method for preparing a thin-film catalyst, characterized in that, Before magnetron sputtering, the substrate is cleaned by glow discharge sputtering, and the gas pressure is evacuated to below 5 × 10⁻⁶. -4 After Pa, argon gas is introduced and the argon gas pressure is controlled at 0.4 Pa to 1.6 Pa. A bias voltage of -300 V to 500 V is applied to the substrate and the glow discharge cleaning time is 10 min to 20 min.

5. The RuO with oxygen vacancies according to claim 2 x A method for preparing a thin-film catalyst, characterized in that, The purity of the ruthenium target is >99.99%.

6. The RuO with oxygen vacancies according to claim 1 x A method for preparing a thin-film catalyst, characterized in that, The substrate is a silicon wafer, titanium felt, or carbon paper.

7. A RuO with oxygen vacancies x Thin film catalyst, characterized in that, It is prepared using any one of the preparation methods of claims 1 to 6.

8. A RuO4 containing oxygen vacancies as described in claim 7 x Application of thin-film catalysts in oxygen evolution through water electrolysis.

9. The application according to claim 8, characterized in that, With RuO x The thin-film catalyst serves as the working electrode, and sulfuric acid is used as the electrolyte to carry out the electrochemical catalytic oxygen evolution reaction.

10. The application according to claim 9, characterized in that, The concentration of sulfuric acid is 0.5 mol / L to 1 mol / L.

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