A high-performance iron-nickel oxide catalytic electrode and its preparation method

Abstract

This invention relates to the field of iron-nickel oxide preparation technology, and discloses a high-performance iron-nickel oxide catalytic electrode and its preparation method. This method achieves efficient and controllable deposition of iron-nickel oxide thin films by optimizing physical vapor deposition (PVD) process parameters. The method has the following advantages: First, it has the capability for large-area continuous production, and the size of the prepared catalytic electrode can be scaled up to the square meter level, fully meeting the needs of industrial applications for large-scale production. Second, through the synergistic optimization of hardware configuration and process parameters, uniform preparation of thin film samples is achieved, effectively ensuring a high degree of consistency in performance between different batches and within the same batch. Finally, during the PVD process, the material is deposited on the substrate surface in the form of high-energy particles. This deposition mechanism significantly enhances the interfacial bonding strength, thereby greatly improving the mechanical stability and long-term durability of the catalytic electrode.

Description

Technical Field

[0001] This invention relates to the field of iron-nickel oxide catalytic electrode preparation technology, specifically to a high-performance iron-nickel oxide catalytic electrode and its preparation method. Background Technology

[0002] The statements in this section provide only background information relevant to the disclosure of this application and may not constitute prior art.

[0003] Iron-nickel oxides, as an important class of transition metal oxides, have shown broad application prospects in energy conversion and storage fields (such as hydrogen production through water electrolysis, fuel cells, and supercapacitors) due to their excellent electrocatalytic activity, chemical stability, and cost-effectiveness. However, the existing fabrication technology of iron-nickel oxide catalytic electrodes still faces many challenges, severely restricting their large-scale commercial application. Currently, traditional preparation methods include hydrothermal synthesis, sol-gel method, and electrochemical deposition method. The hydrothermal synthesis method grows iron-nickel layered double hydroxide precursors under high temperature and high pressure, and then converts them into oxides through calcination. However, this method suffers from problems such as harsh reaction conditions, easy aggregation of product grains, and loss of active sites during calcination. Although the sol-gel method can obtain nanoporous structures with high specific surface area, the metal element ratio is difficult to control precisely, and impurity phases are easily generated during calcination, resulting in poor batch-to-batch reproducibility. Although the electrochemical deposition method can directly deposit iron-nickel hydroxides on conductive substrates, it is difficult to achieve large-area uniform deposition due to limitations in substrate size and edge effects. Therefore, most methods for preparing iron-nickel oxides suffer from core problems such as limited large-scale production, poor structural consistency, uncontrollable crystal phase, and weak interfacial bonding, which severely hinder the large-scale preparation and practical application of iron-nickel oxide catalytic electrodes.

[0004] To address the aforementioned technical shortcomings, physical vapor deposition (PVD) offers advantages such as supporting large-area continuous production, uniform deposition, and good reproducibility. However, the catalytic activity of nickel-iron oxides stems from the synergistic effect between nickel (Ni) and iron (Fe), which is extremely sensitive to the compositional ratio and chemical state of Ni and Fe. Furthermore, the compositional ratio of Ni and Fe is highly sensitive to minute fluctuations during the production process, making it difficult to maintain stability over long-term use. Traditional activation methods aimed at achieving high activity can also lead to preferential oxidation of iron sites, causing irreversible structural damage and iron dissolution, thus severely impairing the long-term stability of the catalyst. Therefore, there is a difficult-to-reconcile trade-off between high activity and long-term stability. Improving the physical vapor deposition process for catalytic electrodes, enhancing their catalytic performance, and addressing the technical challenge of synergistically optimizing catalytic performance, production efficiency, and durability to meet the demands of water electrolysis hydrogen production units for large size, high current density, high efficiency, and stable operation are urgent issues that need to be addressed. Summary of the Invention

[0005] The purpose of this invention is to address the current technical problem of difficulty in synergistically optimizing catalytic performance, production efficiency, and durability by providing a high-performance iron-nickel oxide catalytic electrode and its preparation method. By optimizing process parameters through physical vapor deposition technology, this invention overcomes the technical bottlenecks of traditional methods and solves core problems such as limited large-scale production, poor structural consistency, and poor material stability. This enables efficient large-scale preparation of iron-nickel oxide catalytic electrodes, control of material structure, and synergistic improvement of performance and durability, thereby promoting their industrial application in the field of energy conversion.

[0006] The technical solution of the present invention is as follows: This invention provides a method for preparing a high-performance iron-nickel oxide catalytic electrode, comprising the following steps: Step S1: Pretreatment of carrier material; Step S2: Plasma cleaning of the carrier material; Step S3: Deposit a catalytic coating on the carrier material after step S2; wherein the material of the catalytic coating is one of iron oxide, nickel oxide, molybdenum oxide, cobalt oxide and their alloy oxides; the power for depositing the catalytic coating is 1kW~10kW, and the coating thickness is controlled to be not less than 0.5μm by adjusting the deposition time.

[0007] According to a preferred embodiment, in step S1, the carrier material is one of nickel foam, carbon cloth, nickel felt, nickel mesh, nickel foil, and copper foil.

[0008] According to a preferred embodiment, the pretreatment is a degreasing treatment, specifically, the substrate is ultrasonically cleaned with a weak acid and anhydrous ethanol for 5-30 minutes in sequence, and then dried and stored for later use.

[0009] According to a preferred embodiment, the weak acid is one or more of dilute hydrochloric acid, dilute sulfuric acid, citric acid, phosphoric acid, and 1003A solution.

[0010] According to a preferred embodiment, step S2 includes the following sub-steps: Step S2.1: Place the pretreated carrier material from step S1 into the vacuum chamber of the coating equipment. Set the distance between the conductive substrate and the target (i.e., the target-substrate distance) to between 4 and 20 cm, and adjust the vacuum level to be better than 5 × 10⁻⁶ cm. -3 Pa, introduce high-purity argon gas with a purity of 99.99%, and adjust the gas pressure to 0.2~5 Pa; Step S2.2: Plasma cleaning of the substrate is performed by glow discharge, wherein the voltage is set to 300~800V, the duty cycle is 10~40%, and the plasma cleaning time is 5~60min.

[0011] According to a preferred embodiment, the coating thickness in step S3 is 2 μm.

[0012] Another aspect of the present invention provides an iron-nickel oxide catalytic electrode prepared by the method described above for preparing a high-performance iron-nickel oxide catalytic electrode.

[0013] According to a preferred embodiment, the oxygen vacancy ratio of the iron-nickel oxide catalytic electrode is greater than 33%.

[0014] According to a preferred embodiment, the iron-nickel oxide catalytic electrode has an amorphous structure.

[0015] Another aspect of the present invention provides the application of the iron-nickel oxide catalytic electrode as described above in the field of hydrogen production by water electrolysis.

[0016] Compared with existing technologies, the advantages of this invention are: 1. A high-performance iron-nickel oxide catalytic electrode and its preparation method. This method achieves efficient and controllable deposition of iron-nickel oxide thin films by optimizing physical vapor deposition process parameters. The method has the following advantages: First, it supports large-area continuous production, and the size of the catalytic electrode can reach the square meter level, enabling industrial production. Second, through hardware and process parameter optimization, uniformly distributed thin film samples can be obtained, ensuring the consistency of sample performance. Finally, during physical vapor deposition, the material is deposited on the substrate surface in the form of high-energy particles, which can significantly improve the interfacial bonding strength and enhance the mechanical stability and durability of the catalytic electrode. Attached Figure Description

[0017] Figure 1 The above are X-ray photoelectron spectroscopy (XPS) spectra of the anode material in Embodiment 1 of the present invention, wherein (a) is the full XPS spectrum of the anode material and (b) is the fine XPS spectrum of the O element. Figure 2 This is the X-ray diffraction (XRD) pattern of the iron-nickel oxide coating in Example 1 of the present invention; Figure 3 The images shown are scanning electron microscope (SEM) images of the nickel foam substrate and the iron-nickel oxide catalytic coating in Example 1 of the present invention, wherein (a) is an SEM image of the nickel foam substrate and (b) is an SEM image of the iron-nickel oxide catalytic coating. Figure 4 This is a stability test of the iron-nickel oxide catalytic electrode in an alkaline electrolyzer in Example 1 of the present invention; Figure 5 The electrochemical impedance spectroscopy (EIS) test results and equivalent circuit diagram of the iron-nickel oxide catalytic electrode in Example 1 of this invention are shown. Detailed Implementation

[0018] The specific embodiments listed in this invention are merely examples, and the invention is not limited to the specific embodiments described below. For those skilled in the art, any equivalent modifications and substitutions to the embodiments described below are also within the scope of this invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of this invention should be covered within its scope. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. All reagents or instruments whose manufacturers are not specified are commercially available conventional products. To better illustrate this invention, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this invention can be practiced even without certain specific details. In other embodiments, methods, means, equipment, and steps well known to those skilled in the art are not described in detail in order to highlight the main points of this invention.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Unless otherwise specified, all units used in this specification are International Standard Units (SI), and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors unavoidable in industrial production.

[0020] The 1003A solution used in the following examples is CY-1003A cleaning agent purchased from Dongguan Changyuan Cleaning Technology Service Co., Ltd.

[0021] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0022] Example 1 An anode is prepared by depositing an iron-nickel oxide catalytic coating on a nickel foam substrate. The specific preparation process is as follows: S1: The foamed nickel substrate is degreased and degreased. Specifically, the substrate is ultrasonically cleaned at 50 kHz for 10 min with a 10% concentration of 1003A solution, dried and stored for later use. S2: The pretreated nickel foam substrate is installed and fixed using a specific fixture, and then placed in the vacuum chamber of the physical vapor deposition equipment. The distance between the nickel foam and the target is set to 10 cm. The vacuum chamber door is closed, the coating system is started, and the process is allowed to proceed until the vacuum level is better than 5 × 10⁻⁶ cm. -3 After Pa, high-purity argon gas with a purity of 99.99% is introduced, and the gas pressure is adjusted to 0.5 Pa; S3: Plasma cleaning of the substrate is performed by glow discharge, wherein the voltage is set to 500V, the duty cycle is 20%, and the plasma cleaning time is 20min; S4: A catalytic coating is deposited on the treated conductive substrate, wherein the catalytic material is selected as iron-nickel oxide, the physical vapor deposition method is magnetron sputtering, the coating deposition power is 2kW, the deposition time is 6h, and an iron-nickel oxide catalytic material with a thickness of 2μm is obtained.

[0023] Figure 1 The above are X-ray photoelectron spectroscopy (XPS) spectra of the anode material prepared in Example 1 of this invention, where (a) is the full XPS spectrum of the anode material and (b) is the fine XPS spectrum of the O element.

[0024] like Figure 1 As shown, the XPS image contains Ni, Fe, and O elements. Furthermore, the XPS spectrum of O element reveals that oxygen exists in three states: lattice oxygen, oxygen vacancies, and adsorbed oxygen. Oxygen vacancies account for 33%, indicating that magnetron sputtering can achieve abundant oxygen defects. The formation of oxygen vacancies will alter the energy levels, conductivity, and surface properties of the anode material, thus playing a positive role in the OER reaction.

[0025] Furthermore, the crystal structure of the iron-nickel oxide catalytic coating obtained by magnetron sputtering in Example 1 was characterized using X-ray diffraction. Specific test results are as follows: Figure 2 As shown.

[0026] like Figure 2 As shown, the iron-nickel oxide catalytic coating prepared by this invention has the same diffraction peaks as the standard card (PDF#10-0325), indicating that the iron-nickel oxide catalytic coating was successfully synthesized in this embodiment. Furthermore, the XRD pattern shows that the iron-nickel oxide catalytic coating prepared by magnetron sputtering has an amorphous structure.

[0027] Figure 3 The images shown are scanning electron microscope (SEM) images of the nickel foam substrate and the iron-nickel oxide catalytic coating in Example 1 of the present invention, wherein (a) is an SEM image of the nickel foam substrate and (b) is an SEM image of the iron-nickel oxide catalytic coating.

[0028] like Figure 3 As shown, the foamed nickel substrate has a smooth metal surface, and after the deposition of the iron-nickel oxide catalytic coating, the surface has a thin film with a loose structure.

[0029] Furthermore, the electrolytic stability of the iron-nickel oxide anode in an alkaline electrolytic cell was tested, and the specific test results are as follows: Figure 4 As shown in the figure. The electrolyte is 1M KOH, the cathode is a Pt / C electrode (40wt%Pt), the anode is the iron-nickel oxide anode prepared in Example 1, and the membrane is an anion exchange membrane.

[0030] like Figure 4As shown, the iron-nickel oxide anode provided by this invention operates at 1 A / cm. 2 The fact that it can operate stably for 100 hours at a current density below 1.9V indicates that the iron-nickel oxide electrode has high stability and activity.

[0031] Furthermore, electrochemical impedance spectroscopy (EIS) was performed on the iron-nickel oxide anode in Example 1, with a frequency range of 10 Hz. 5 ~1 Hz, AC amplitude of 5 mV, test temperature of 25℃, specific test results are as follows: Figure 5 As shown.

[0032] Figure 5 The electrochemical impedance spectroscopy (EIS) test results and equivalent circuit diagram of the iron-nickel oxide anode in Example 1 of this invention are shown.

[0033] like Figure 5 As shown, electrochemical impedance spectroscopy (EIS) tests were performed on nickel foam (NF) and nickel iron oxide anodes. The results showed that the charge transfer impedance (Rct) of NF and nickel iron oxide electrodes were 25.2Ω and 2.4Ω, respectively. This indicates that the charge transfer rate on the surface of the nickel iron oxide anode is faster, which means that it can accelerate the charge transfer process in the electrocatalytic process. Therefore, it has higher catalytic efficiency and conductivity, resulting in better OER performance of the nickel iron oxide electrode.

[0034] In summary, this invention successfully prepared a nickel-iron oxide electrode using magnetron sputtering. The nickel-iron oxide catalytic coating has an amorphous structure, providing a large number of active sites. The prepared nickel-iron oxide catalytic coating contains abundant oxygen vacancies, which not only provide abundant catalytic active sites but also accelerate the charge transfer process during electrocatalysis, thereby improving OER performance. Furthermore, by utilizing the abundant oxygen vacancies and active sites in the nickel-iron oxide catalytic coating, more active sites are provided for the OER reaction while accelerating charge transfer, resulting in a low voltage and high stability for the nickel-iron oxide anode.

[0035] The embodiments described above merely illustrate specific implementation methods of this application, and while the descriptions are detailed and specific, they should not be construed as limiting the scope of protection of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the technical solution of this application, and these modifications and improvements all fall within the scope of protection of this application.

Claims

1. A method for preparing a high-performance iron-nickel oxide catalytic electrode, characterized in that, Includes the following steps: Step S1: Pretreatment of carrier material; Step S2: Plasma cleaning of the carrier material; Step S3: Deposit a catalytic coating on the support material after the treatment in step S2; The catalytic coating material is one of iron oxide, nickel oxide, molybdenum oxide, cobalt oxide and their alloy oxides; the power for depositing the catalytic coating is 1kW~10kW, and the coating thickness is controlled to be no less than 0.5μm by adjusting the deposition time.

2. The method for preparing a high-performance iron-nickel oxide catalytic electrode according to claim 1, characterized in that, In step S1, the carrier material is one of the following: nickel foam, carbon cloth, nickel felt, nickel mesh, nickel foil, and copper foil.

3. The method for preparing a high-performance iron-nickel oxide catalytic electrode according to claim 1, characterized in that, In step S1, the pretreatment is a degreasing treatment, specifically, the substrate is ultrasonically cleaned with weak acid and anhydrous ethanol for 5-30 minutes in sequence, and then dried and stored for later use.

4. The method for preparing a high-performance iron-nickel oxide catalytic electrode according to claim 3, characterized in that, The weak acid in step S1 is one or more of dilute hydrochloric acid, dilute sulfuric acid, citric acid, phosphoric acid, and 1003A solution.

5. The method for preparing a high-performance iron-nickel oxide catalytic electrode according to claim 1, characterized in that, Step S2 includes the following sub-steps: Step S2.1: Place the pretreated carrier material from step S1 into the vacuum chamber of the coating equipment. Set the distance between the conductive substrate and the target material to be between 4 and 20 cm, and adjust the vacuum level to be better than 5 × 10⁻⁶ cm. -3 Pa, introduce high-purity argon gas with a purity of 99.99%, and adjust the gas pressure to 0.2~5 Pa; Step S2.2: Plasma cleaning of the substrate is performed by glow discharge, wherein the voltage is set to 300~800V, the duty cycle is 10~40%, and the plasma cleaning time is 5~60min.

6. The method for preparing a high-performance iron-nickel oxide catalytic electrode according to claim 1, characterized in that, The coating thickness in step S3 is 2 μm.

7. An iron-nickel oxide catalytic electrode prepared by the method for preparing a high-performance iron-nickel oxide catalytic electrode as described in any one of claims 1-6.

8. The high-performance iron-nickel oxide catalytic electrode according to claim 7, characterized in that, The oxygen vacancy ratio of the iron-nickel oxide catalytic electrode is greater than 33%.

9. A high-performance iron-nickel oxide catalytic electrode according to claim 7, characterized in that, The iron-nickel oxide catalytic electrode has an amorphous structure.

10. The application of the iron-nickel oxide catalytic electrode as described in claim 7 in the field of hydrogen production by water electrolysis.

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