Method for in-situ construction of integrated three-phase electrode with mesoporous multi-metallic catalytic interface by laser cladding-dealloying technology

Abstract

This invention provides a method for in-situ construction of an integrated three-phase electrode with a mesoporous multimetallic catalytic interface using laser cladding-dealloying technology. Using a three-phase electrode substrate as a template, catalytic metal (M1) and active metal (M2) are deposited on its surface by magnetron sputtering. a A bimetallic alloy layer (M1-M1) is formed by laser ablation cladding. a Then, the M is removed by wet etching or electrochemical oxidation. a The components are combined to form a three-dimensional continuous mesoporous catalytic metal interface (3D-M1); finally, a second catalytic metal interface (M2) is added through atomic layer deposition (ALD) or electrochemical electroplating (ECD) to obtain an integrated three-phase electrode (3D-M1-M2) with a mesoporous multi-metal catalytic interface. This invention significantly improves processing efficiency, precision, controllability, substrate versatility, and electrode catalytic performance, and is of great significance to the research and industrialization of technologies such as electrochemical hydrogen production, fuel cells, and metal-air batteries.

Description

Technical Field

[0001] This invention relates to the research fields of electrochemical energy conversion, sensor technology, and clean energy devices. Specifically, it discloses a laser cladding-dealloying technology that can construct mesoporous multimetallic catalytic interfaces in situ on various three-phase electrode substrates such as hydrophilic / hydrophobic carbon paper, conductive polymer films, conductive ceramics, and metal foams. Background Technology

[0002] In current integrated three-phase electrode fabrication methods, commonly used techniques include coating, spraying, heat treatment, electrochemical deposition, and sol-gel methods. While coating is simple, it suffers from difficulties in controlling liquid flow and drying speed, potentially leading to uneven coatings or defects, limiting its applicability, especially for certain electrode materials and applications. Spraying, on the other hand, can achieve uniform catalyst distribution, but it is limited to carbon paper or other support surfaces; for some thin-film electrodes, precise film thickness control may be difficult. Heat treatment optimizes the lattice arrangement by altering the crystal structure of the electrode material, improving conductivity and stability. However, at high temperatures, heat treatment may damage the substrate material structure, leading to reduced conductivity. Electrochemical deposition exhibits significant advantages in high controllability and uniformity, particularly suitable for electrodes with complex structures. However, its deposition rate is relatively limited, potentially resulting in longer fabrication cycles, and it is limited to specific materials, requiring specific underlying electrodes. The sol-gel method, through sol preparation and gel formation, provides a pathway for uniform electrode deposition. It has the advantages of simple preparation process, relatively low cost, and strong controllability. However, it should be noted that the sol-gel method may present certain challenges in the precise control of film thickness.

[0003] In the current research context, higher demands are being placed on improving the efficiency, accuracy, controllability, and substrate universality of technologies such as electrochemical hydrogen production, fuel cells, and metal-air batteries. Currently, there is still a lack of a controllable, accurate, and universally applicable electrode fabrication method to meet the requirements for integrated three-phase electrodes. Summary of the Invention

[0004] To address the aforementioned problems and shortcomings in the field, this invention provides a laser cladding-dealloying technology that enables in-situ construction of mesoporous multimetallic catalytic interfaces on various three-phase electrode substrates such as hydrophilic / hydrophobic carbon paper, conductive polymer films, conductive ceramics, and metal foams. This technology achieves an integrated three-phase electrode with good conductivity, precisely controllable electrode thickness, and universal substrate applicability.

[0005] The technical solution of this invention includes the following:

[0006] A target catalytic metal (M1), such as Ni, Cu, Au, Pt, or Pd, of a certain thickness is first deposited on various three-phase electrode substrates, including hydrophilic / hydrophobic carbon paper, conductive polymer films, conductive ceramics, and metal foams, using magnetron sputtering. Then, a second active metal (M2) with higher reactivity than the target catalytic metal is sputtered onto the substrate. a Materials such as Mn, Ag, Zn, Fe, and V are used, and the specific metal deposition thickness depends on the mesoporous size of the desired mesoporous metal. Subsequently, laser ablation is used to clad the two metals together to form a bimetallic composite alloy layer (M1-M2). a The formed bimetallic alloy layer was placed in an inert argon atmosphere, and the active metal in the bimetallic alloy was etched using a wet etching process with approximately 0.03M dilute hydrochloric acid (see attached image). Figure 2 Remove it using methods such as electrochemical oxidation etching (with attachment). Figure 3 The method involves using approximately 0.1M nitric acid as the etching solution, applying a voltage range of 0.1-0.3V vs. RHE, and etching for 5-15 minutes. The etching time can be adjusted by changing the anode potential, reaction time, and nitric acid concentration, depending on the properties and thickness of the different active metals. This forms a three-dimensional continuous mesoporous catalytic metal interface (3D-M1) on the electrode surface. For the deposition of the second metal, atomic layer deposition (ALD) or electrochemical electroplating (ECD) methods can be used. In ALD, the substrate material is replaced with the three-dimensional continuous mesoporous catalytic metal interface (3D-M1) prepared above, and then metals such as Ti, Al, and Zr are deposited. In ECD, different metal ligands are used as electrolyte solutions, and a specific metal is deposited at different deposition voltages to obtain an integrated three-phase electrode (3D-M1-M2) with a mesoporous multi-metal catalytic interface.

[0007] This type of three-phase electrode can be directly applied to key dual-carbon technologies such as AEM and PEM hydrogen production, metal-air batteries, fuel cells, and energy electrocatalysis (CO2 reduction, alcohol and methane oxidation, etc.). Specific application examples are attached. Figure 4 As shown.

[0008] The present invention has the following advantages due to the adoption of the above technical solutions:

[0009] (1) The electrodes have good conductivity.

[0010] Most conventional integrated three-phase electrodes are prepared by coating or spraying catalytic materials onto a three-phase substrate. This requires the addition of Nafion as a binder to ensure a tight bond between the catalytic material and the substrate, which can lead to poor conductivity in the integrated electrode. Although conductive carbon black is added during slurry preparation to enhance conductivity, it still has limitations. Electrodes prepared using laser cladding-dealloying technology, however, exhibit excellent conductivity because they use sputtered metal as the substrate.

[0011] (2) High universality

[0012] This technology can construct mesoporous multimetallic catalytic interfaces in situ on various three-phase electrode substrates such as hydrophilic / hydrophobic carbon paper, conductive polymer films, conductive ceramics, and metal foams. It offers a variety of three-phase substrates to choose from and allows for different metal combinations to be selected for preparation.

[0013] (3) Precise control of electrode thickness

[0014] Using magnetron sputtering to prepare materials allows for precise control of the thickness of the catalytic metal by changing the sputtering time, thus meeting experimental requirements.

[0015] (4) The method is simple and easy to operate.

[0016] After sputtering, the bimetallic interface can be ablated by laser to form an alloy, which can then be transformed into a three-dimensional continuous mesoporous metal through acid pickling or electrochemical oxidation. The method is simple and easy to operate. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the fabrication process of the 3D-M1 three-dimensional mesoporous metal electrode metal;

[0018] Figure 2 This is a schematic diagram of wet etching;

[0019] Figure 3 This is a schematic diagram of electrochemical oxidation etching;

[0020] Figure 4 These are examples of the use of 3D-M1-M2 in different systems;

[0021] Figure 5 This is a schematic diagram of the fabricated 3D-M1 electrode;

[0022] Figure 6 These are scanning electron microscope (SEM) images and elemental mapping diagrams of the 3D-Ni electrode fabricated in Example 1 at different scales;

[0023] Figure 7The comparison of OER and ORR electrochemical performance tests between 3D-Ni electrode and ordinary three-phase Ni electrode is as follows: A and B are the LSV test and Tafel slope of OER, respectively; C and D are the LSV test and Tafel slope of GOR, respectively; C and D are the ECSA test and electrochemical EIS test, respectively.

[0024] Figure 8 These are scanning electron microscope (SEM) images and elemental mapping diagrams of the 3D-Cu electrode fabricated in Example 2 at different scales;

[0025] Figure 9 The comparison of CO2RR electrochemical performance tests between 3D-Cu electrode and ordinary three-phase Au electrode is as follows: A and B are LSV test and Tafel slope, respectively; C and D are ECSA test and electrochemical EIS test, respectively.

[0026] Figure 10 These are scanning electron microscope (SEM) images and elemental mapping diagrams of the 3D-Au electrode fabricated in Example 3 at different scales;

[0027] Figure 11 The comparison of the MOR electrochemical performance of 3D-Au electrode and ordinary three-phase Au electrode: A and B are LSV test and ECSA test, respectively;

[0028] Figure 12 These are SEM images of the 3D-Au-Cu gas diffusion electrode at the 100nm and 1μm scales. Detailed Implementation

[0029] 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 with reference to specific embodiments, but the embodiments are not intended to limit the present invention.

[0030] Example 1: Fabrication of 3D-Ni Electrode

[0031] Metal coatings of catalytic metal Ni (100 nm) and active metal Mn (120 nm) were deposited on carbon paper by magnetron sputtering. Laser ablation cladding was then performed at a power of 9 W and a scan rate of 120 mm / s to form a bimetallic alloy layer (Ni-Mn). Subsequently, wet etching was carried out under an argon atmosphere using approximately 0.03 M dilute hydrochloric acid as the etching solution. (See attached image) Figure 2 Etching for 15 minutes completely removed the active metal Mn from the alloy, forming a three-dimensional mesoporous metal (3D-Ni). The resulting three-dimensional mesoporous metal was observed under a scanning electron microscope as shown in the image. Figure 6 As shown, a 3D-Ni mesoporous structure can be seen on its surface, proving that an integrated three-phase electrode with a three-dimensional mesoporous structure has been successfully fabricated.

[0032] The electrochemical performance of the 3D-Ni electrode for the oxygen reduction reaction (OER) and glycerol oxidation (GOR) was tested, and the results are as follows: Figure 7 By comparing the electrochemical performance of a three-phase Ni-based electrode (Ni) prepared by a coating method with that of a three-dimensional mesoporous metal (3D-Ni), linear sweep voltammetry (LSV) curves in the OER can be observed, with current densities reaching -10 mA·cm⁻¹. -2 At that time, the overpotential of 3D-Ni was significantly lower than that of ordinary three-phase Ni electrode. Tafel curves showed that 3D-Ni had better OER reaction kinetics, with a Tafel slope of 70 mV·dec. -1 The current density of 3D-Ni is lower than that of ordinary Ni electrodes. We then investigated the GOR performance of the two electrodes; the current density of 3D-Ni was lower than that of ordinary Ni electrodes. Tafel curves also showed that 3D-Ni exhibits better GOR kinetics compared to ordinary Ni electrodes. By comparing the electrochemical active area (ECSA) and electrochemical impedance spectroscopy (EIS), the ECSA of 3D-Ni was 0.00394 mF·cm⁻¹. -2 It has a higher effective electrochemical active area, and EIS tests show that 3D-Ni has lower charge transfer resistance and a faster GOR kinetic rate.

[0033] Example 2: Fabrication of 3D-Cu Electrode

[0034] Metal coatings of catalytic metal Cu (130 nm) and active metal Mn (120 nm) were deposited on carbon paper by magnetron sputtering. A bimetallic alloy layer (Cu-Mn) was formed by laser ablation cladding at a power of 9 W and a scan rate of 150 mm / s, resulting in a strong interaction between the two metals. Subsequently, wet etching was performed under an argon atmosphere using approximately 0.03 M dilute hydrochloric acid as the etching solution. (See attached image) Figure 2 Etching for 3 hours completely removes the active metal Mn from the alloy, forming a three-dimensional mesoporous metal (3D-Cu). The resulting 3D-Cu appears as shown in the scanning electron microscope image. Figure 8 As shown, the Mn component in the alloy has been completely removed, and the mesopores are formed relatively uniformly.

[0035] The electrochemical performance of 3D-Cu electrodes and Cu electrodes prepared by conventional coating methods for the carbon dioxide reduction reaction (CO2RR) was compared and tested. The test results are as follows: Figure 9 As shown in the figure. The LSV curves show that the current density of 3D-Cu is significantly higher than that of ordinary Cu-based electrodes, proving its excellent CO2RR performance. The Tafel slope obtained from the LSV curves indicates that ( Figure 9 A) Tafel slope of 3D-Cu (308mV·dec)-1 ) lower than that of ordinary Cu electrodes (328mV·dec) -1 This indicates that its reaction kinetics are faster. Furthermore, its ECSA and EIS both exhibit superior electrochemical performance compared to Cu electrodes prepared by the coating method.

[0036] Example 3: Fabrication of 3D-Au Electrode

[0037] Metal coatings of catalytic metal Au (80 nm) and active metal Ag (100 nm) were deposited on carbon paper using an ion sputtering apparatus. Under conditions of 12 W power and a scan rate of 120 mm / s, a bimetallic alloy layer (Au-Ag) was formed by laser ablation. Subsequently, using 0.15 M nitric acid solution as the electrolyte, an electrochemical oxidation etching process was employed to dissolve and etch the Ag component in the alloy film, forming a 3D-Au thin film structure with a three-dimensional continuous mesoporous substrate. The resulting three-dimensional mesoporous gold electrode appears as shown in the scanning electron microscope image. Figure 10 As shown.

[0038] The electrochemical performance of the 3D-Au electrode and the Au electrode prepared by the conventional coating method for the methane oxidation reaction (MOR) was tested, and the test results are as follows: Figure 11 The LSV curves show that the oxidation potential of methane in 3D-ACu is reduced, indicating better MOR performance. Furthermore, the ECSA value is 1.09 mF·cm⁻¹. -2 This demonstrates that it has a higher effective electrochemical active area.

[0039] Example 4: Fabrication of 3D-Au-Cu Electrode

[0040] Au and Ag nanolayers of 100 nm were deposited on porous carbon paper by magnetron sputtering, and Au-Ag alloy / solid solution films (precursors) were formed by laser ablation cladding. Using 0.15 M nitric acid solution as the electrolyte, the main Ag component in the alloy film was dissolved and etched through an electrochemical oxidation etching process to construct a three-dimensional continuous mesoporous gold (3D-Au) film material. Subsequently, Cu was loaded using atomic layer deposition (ALD) with (CuCl)3 as the metal precursor, and 2 nm of Cu was deposited at 250 °C to obtain a three-dimensional mesoporous multi-metal integrated three-phase electrode, 3D-Au-Cu. Its scanning electron microscope (SEM) image is attached. Figure 12 As shown.

Claims

1. A method for in-situ construction of an integrated three-phase electrode with a mesoporous multimetallic catalytic interface using laser cladding-dealloying technology, characterized in that, Includes the following steps: Fabrication of mesoporous multimetal integrated three-phase electrodes: Magnetron sputtering was used to deposit catalytic metal M1 and active metal M1 with thicknesses of 80-150 nm on three-phase electrode substrates, including hydrophilic / hydrophobic carbon paper, conductive polymer thin film, conductive ceramic, and metal foam. a A bimetallic alloy layer M1-M was formed by laser ablation cladding under conditions of 9-12 W power and 100-150 mm / s scanning speed. a Then, wet etching is performed in 0.03-0.05 M dilute hydrochloric acid for 15 min-3 h; or electrochemical oxidation etching is performed using 0.1-0.3 M nitric acid as the etching solution, applying a voltage range of 0.1-0.3 V vs. RHE for 5-30 min to form a three-dimensional continuous mesoporous catalytic metal interface, i.e., 3D-M1, on the electrode surface; the second type of catalytic metal M2 is loaded by atomic layer deposition. Using 3D-M1 as the substrate for atomic layer deposition, precursors of metal oxides of Pt, Ti, or Al are vaporized at a reaction temperature of 200-300℃ and deposited on the surface of 3D-M1 to obtain an integrated three-phase electrode 3D-M1-M2 with a mesoporous multimetallic catalytic interface.

2. Applications of the integrated three-phase electrode with mesoporous multimetallic catalytic interface prepared by the method described in claim 1 in the fields of hydrogen production by AEM and PEM, metal-air batteries, fuel cells, and energy electrocatalysis.

Images