Preparation method for ZnO-derived zeolite imidazole ZIF structure supported metal catalyst grown on flexible carbon nanotube film

Abstract

The invention relates to the technical field of nano catalysts, in particular to a preparation method of a flexible carbon nanotube film growth ZnO derived zeolite imidazole ZIF structure loaded metal catalyst, which comprises the following steps: S1, taking an integrated substrate material selected from a single-walled carbon nanotube film, carbon cloth, carbon paper, a zinc sheet or foamed nickel; s2, growing a ZnO array on the integrated substrate material through an electro-deposition method, a chemical growth method or a physical extrusion method; s3, putting the integrated substrate material on which the ZnO array grows into a solution containing 2-methylimidazole and a metal source, and generating a zeolite imidazole ZIF structure through self-assembly, so that metal is embedded into a ZIF skeleton; and S4, performing pyrolysis treatment on the product in the step S3 in an inert atmosphere to obtain the metal-loaded ZnO-derived ZIF structure catalyst. According to the preparation method, catalytic layer-substrate strong coupling and oxygen reduction activity improvement are achieved, the obtained self-supporting electrode shows 0.82 V half-wave potential in the zinc-air battery, and traditional binder dependence and metal load limitation are broken through.

Description

Technical Field

[0001] The invention relates to the technical field of nanocatalysts, and in particular to a method for preparing a flexible carbon nanotube film grown ZnO-derived zeolite imidazole ZIF structure-loaded metal catalyst. Background Art

[0002] Currently, most supported metal catalysts exist in powder form. This hinders direct application in practical applications, requiring the support of expensive organic adhesives. Furthermore, powder recovery during solid-liquid separation is difficult, further hindering their widespread adoption. However, integrated, self-supporting catalysts not only enable rapid diffusion and transport of reactants and products such as oxygen, but also improve electron transfer and transport. Using integrated, self-supporting catalysts eliminates the need for expensive adhesives, reducing costs. Furthermore, they increase the active surface area and active sites of the catalyst to a certain extent, maintain good mass transfer pathways, improve catalytic efficiency, and ensure both electronic conductivity and mechanical stability of the battery electrode. Using a grafting technique, ZnO is pre-electrodeposited onto an integrated flexible single-walled CNT film. The ZnO hydrolysis effect is then exploited to assemble a metal-doped ZIF structure on the surface. This is then pyrolyzed to yield a high-performance, metal-supported Fe-NCl / PC / SWCNT integrated thin film catalyst.

[0003] Prior art has disclosed a method for preparing a flexible carbon nanotube film-supported metal single-atom catalyst. This method uses a flexible carbon nanotube film as an integrated substrate and directly pyrolyzes and sublimes a phthalocyanine metal salt to produce the flexible carbon nanotube film-supported metal single-atom catalyst. This method is simple and effective and can be used for large-scale synthesis of single-atom catalysts. However, the method requires the use of a low-temperature sublimable phthalocyanine metal salt, which may limit the type of supported metal and the type of metal present, hindering the widespread application of this type of catalyst.

[0004] In view of the above problems, the development of integrated electrocatalysts has important industrial application value. The characteristics of the integrated carrier substrate material do not limit the application scope of the electrocatalyst and have wide practical applications in industry. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method for a metal catalyst loaded on a ZnO-derived zeolite imidazole ZIF structure grown on a flexible carbon nanotube film. A ZnO array template is constructed on a substrate by electrodeposition / oxidation, and its hydrolysis effect is utilized to guide the self-assembly of the metal-doped ZIF structure. A chemical bonding interface and single-atom active sites are formed through thermal decomposition, thereby achieving strong coupling between the catalytic layer and the substrate and enhancing the oxygen reduction activity. The resulting self-supporting electrode exhibits a half-wave potential of 0.82V in a zinc-air battery, breaking through the traditional binder dependence and metal loading limitations.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0007] A method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film comprises the following steps:

[0008] S1: taking an integrated substrate material, wherein the integrated substrate material is selected from single-walled carbon nanotube film, carbon cloth, carbon paper, zinc sheet or nickel foam;

[0009] S2: growing a ZnO array on the integrated substrate material by electrodeposition, chemical growth or physical extrusion;

[0010] S3: placing the integrated substrate material with the ZnO array in a solution containing 2-methylimidazole and a metal source to generate a zeolitic imidazole ZIF structure through self-assembly, so that the metal is embedded in the ZIF framework;

[0011] S4: thermally decomposing the product of step S3 under an inert atmosphere to obtain a metal-loaded ZnO-derived ZIF structure catalyst.

[0012] Furthermore, in step S1, the single-walled carbon nanotube film is prepared by a floating catalyst chemical vapor deposition method, the collection time is 15 to 30 minutes, and the film thickness is 0.25 to 0.5 mm.

[0013] Furthermore, in step S2, the electrochemical deposition method uses an electrolyte containing 6M potassium hydroxide and 0.2M zinc acetate to electrochemically deposit a ZnO array on the substrate surface by simulating the charging process of a zinc-air battery.

[0014] Furthermore, in step S2, the integrated base material and the zinc sheet are compounded by a physical extrusion method through a roller press and then oxidized to form a ZnO array.

[0015] Furthermore, in step S3, the self-assembly reaction time is 12 to 48 hours; and the metal source is at least one of hemin, cobalt salt or nickel salt.

[0016] Furthermore, in step S4, the temperature of the pyrolysis treatment is 900-1000° C., and the holding time is 1-2 hours; and the inert atmosphere is argon.

[0017] Furthermore, the metal is embedded in the ZIF framework in the form of a single atom, and the metal is selected from at least one of iron, cobalt or nickel.

[0018] On the other hand, the present invention proposes a flexible carbon nanotube film grown ZnO-derived zeolite imidazole ZIF structure-loaded metal catalyst prepared by the above method, wherein the catalyst includes an integrated substrate material, a ZnO array-derived ZIF structure and embedded metal active sites.

[0019] Furthermore, the oxygen reduction reaction (ORR) half-wave potential of the catalyst in a 0.1M HClO4 electrolyte is 0.8 to 0.82V, and the performance decay is ≤6mV after 5000 cycles.

[0020] On the other hand, the present invention proposes the use of the above catalyst in a zinc-air battery, characterized in that the catalyst is directly used as an electrode material.

[0021] Beneficial effects of the present invention:

[0022] The present invention uses a flexible single-walled carbon nanotube film prepared by a floating catalyst chemical vapor deposition method as an integrated substrate. Its self-supporting properties and three-dimensional conductive network provide a stable carrier for the uniform loading of catalytic active sites. After the substrate is treated with oxygen plasma to enhance its hydrophilicity, a ZnO array is grown by electrodeposition or physical extrusion. The array not only serves as a template to guide the subsequent self-assembly of the ZIF structure, but its strong interface bonding with the carbon nanotube surface ensures the mechanical riveting of the substrate and the catalytic layer. During the self-assembly process, ZnO releases zinc ions through hydrolysis and coordinates with 2-methylimidazole to form a ZIF skeleton. At the same time, the introduced metal precursor is anchored in situ in the coordination network and is eventually converted into a stable metal-NC single-atom site through thermal decomposition. The continuous conductive network of carbon nanotubes directly accelerates electron transport, while the hierarchical porous carbon structure derived from ZIF promotes the diffusion of reactants. The combination of the two enables the catalyst to maintain structural integrity and high catalytic activity during bending or electrochemical cycling, overcoming the defects of traditional powder catalysts that rely on binders, such as high interfacial resistance and easy loss of active sites.

[0023] The present invention utilizes the template effect and coordination ability of ZnO to dynamically control the loading of metal single atoms. In dimethylimidazole solution, the ZnO surface hydrolyzes and releases Zn 2+ The ZIF-8 framework is self-assembled with organic ligands. Its open pore structure and exposed coordination sites provide an ideal microenvironment for the embedding of metal precursors. Metal ions are strongly coordinated with imidazole nitrogen. The metal atoms are locked in the ZIF framework. During the pyrolysis process, ZIF is carbonized into a nitrogen-doped carbon matrix, and the metal atoms migrate to the N coordination sites at high temperature to form atomically dispersed MN. x Active center. By adjusting the growth time of ZnO and the type of metal precursor, the loading density and coordination environment of metal single atoms can be precisely controlled. When hemin is introduced, its Fe 3+It preferentially occupies the tetrahedral sites in the ZIF framework, forming an Fe-N4 configuration after pyrolysis, significantly enhancing the oxygen reduction reaction (ORR) activity. This strategy breaks through the limitations of traditional sublimation methods on the type of metals and enables flexible expansion from transition metals to precious metals.

[0024] The present invention uses multi-path processes such as electrochemical deposition, hydrothermal method and physical extrusion to grow ZnO arrays on different substrates, giving the technical solution a high degree of universality. Taking carbon cloth as an example, in a 6M KOH and 0.2M zinc acetate electrolyte, ZnO nanorod arrays are electroplated by simulating the charging process of a zinc-air battery. Its vertically oriented structure provides a high specific surface area template for ZIF self-assembly; for zinc foil substrates, a ZnO layer can be directly generated by surface oxidation, and then the metal is loaded through ZIF derivatization. The physical extrusion method combines the zinc sheet with the flexible substrate through a roller press, and uses mechanical pressure to induce ZnO formation. Regardless of whether the substrate is in the form of a flexible film or a rigid sheet, the catalyst can be constructed through an adaptive ZnO growth method. This design not only expands the scope of application of the substrate material, but also enables the catalyst to adapt to the mechanical strength and conductivity requirements of different application scenarios.

[0025] The integrated structural design of the present invention combined with the efficient exposure of single metal atoms enables the catalyst to exhibit excellent stability and activity in harsh electrochemical environments. In the ORR test, the Fe-NC active site significantly reduced the reaction overpotential by optimizing the O2 adsorption energy barrier and the intermediate conversion path, and the half-wave potential was close to that of commercial Pt / C. The continuous conductive network of the carbon nanotube substrate and the mesoporous structure derived from ZIF synergistically accelerate the electron / mass transfer process, while the strong covalent bonding of the single atom site and the nitrogen-doped carbon effectively inhibits metal agglomeration. When applied to zinc-air batteries, the integrated characteristics of the catalyst reduce the electrode / electrolyte interface impedance, and its high specific capacity and power density are directly derived from the full utilization of the active sites and the rapid reaction kinetics. In addition, the graphitized carbon layer formed during the pyrolysis process further enhances the material's antioxidant properties and chemical stability, ensuring that the catalyst does not degrade during long-term operation in strong acid or alkaline environments, meeting the life requirements of commercial electrochemical devices.

[0026] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 It is an experimental flow chart of the present invention;

[0029] Figure 2 Schematic diagrams of the SEM images of materials during the preparation of the Fe-NCl / PC / SWCNT thin film catalyst in Example 4 of the present invention; (a1)(a2) schematic diagrams of scanning of single-walled carbon nanotube thin films; (b1)(b2) schematic diagrams of the SEM images of PPy / SWCNT thin films; (c1)(c2) schematic diagrams of the SEM images of ZnO / PPy / SWCNT thin films;

[0030] Figure 3 Schematic diagram of the optical structure of the Fe-NCl / PC / SWCNT thin film catalyst in Example 4 of the present invention;

[0031] Figure 4 Schematic diagrams of TEM images of the Fe-NCl / PC / SWCNT thin film catalyst at different magnifications in Example 4 of the present invention; (a) TEM diagram of the Fe-NCl / PC / SWCNT thin film at a 200 nm scale; (b) TEM diagram of the Fe-NCl / PC / SWCNT thin film at a 20 nm scale;

[0032] Figure 5 Schematic diagram of XRD of Fe-NCl / PC / SWCNT thin film catalyst in Example 4 of the present invention;

[0033] Figure 6 Schematic diagram of spherical aberration of the Fe-NCl / PC / SWCNT thin film catalyst in Example 4 of the present invention; (a) surface structure of the Fe-NCl / PC / SWCNT thin film catalyst before pyrolysis; (b) surface structure of carbon nanotubes in the Fe-NCl / PC / SWCNT thin film catalyst;

[0034] Figure 7 Schematic diagram of the ORR performance of the Fe-NCl / PC / SWCNT thin film catalyst in Example 4 of the present invention;

[0035] Figure 8 Schematic diagram of the ORR stability of the Fe-NCl / PC / SWCNT thin film catalyst in Example 4 of the present invention;

[0036] Figure 9 Schematic diagram of the power density of an aqueous zinc-air battery assembled with a Fe-NCl / PC / SWCNT thin film catalyst in Example 4 of the present invention;

[0037] Figure 10 Schematic diagram of the specific capacity of an aqueous zinc-air battery assembled with a Fe-NCl / PC / SWCNT thin film catalyst in Example 4 of the present invention;

[0038] Figure 11Schematic diagram of the ORR performance of a single-atom iron catalyst supported on a ZnO-derived ZIF structure grown by electrodeposition of an integrated zinc sheet in Example 2 of the present invention;

[0039] Figure 12 Schematic diagram of the ORR performance of the integrated Fe-N / SWCNT thin film catalyst in Example 3 of the present invention;

[0040] Figure 13 Schematic diagram of the optical structure of the single-atom iron catalyst prepared by the ZnO-derived ZIF structure grown by electrodeposition of an integrated zinc sheet in Example 2 of the present invention; (a) ZnO / Zn, a zinc foil after ZnO growth; (b) Fe-ZIF / Zn, a zinc foil after ZIF structure growth; (c) Fe-N / C obtained by pyrolysis;

[0041] Figure 14 Schematic diagram of XPS characterization during the growth of a ZnO-derived zeolite imidazole ZIF structure-loaded metal catalyst on a flexible carbon nanotube film as described in Example 1 of the present invention; (a) Full XPS spectra of H-ZIF-8 / ZnO / PPy / SWCNT obtained after growing ZIF and Fe-NCl / PC / SWCNT obtained after pyrolysis thereof, as well as high-energy XPS spectra of each element during pyrolysis at different temperatures (b) High-energy XPS spectrum of N 1s (c) High-energy XPS spectrum of O 1s (d) High-energy XPS spectrum of Cl 2p (e) High-energy XPS spectrum of Fe 2p (f) High-energy XPS spectrum of Zn 2p. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0043] Example 1

[0044] As described in this embodiment, a method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film is as follows:

[0045] S1: Growing high-quality, self-supporting single-walled carbon nanotube films using floating catalyst chemical vapor deposition. Collecting 30-minute-thick films, the films were directly torn off for use in the reaction.

[0046] S2: The single-walled carbon nanotube film is treated with an oxygen plasma to ensure its hydrophilicity. It is then placed in an electrolyte solution containing pyrrole and electroplated with polypyrrole using cyclic voltammetry. The film is cycled from 0-1.2V for 60-100 cycles. It is then thermally decomposed and placed in a 6M potassium hydroxide and 0.2M zinc acetate solution to simulate the charging process. ZnO arrays are grown on the single-walled carbon nanotube film.

[0047] S3: The single-walled carbon nanotube film with the ZnO array grown in S2 was placed in a DMF solution containing 1.63g of 2-methylimidazole and 150mg of hemin chloride, and the temperature was kept at 90°C for 12h. Zeolite imidazole ZIF structure was grown on the single-walled carbon nanotube film using ZnO as a template, and single Fe atoms were embedded. Within 2 hours, the temperature was gradually raised to 1000°C in an argon environment, kept warm for 2 hours, and then cooled naturally.

[0048] Example 2

[0049] As described in this embodiment, a method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film is as follows:

[0050] S1: Cut the zinc foil into 5*5cm squares, calcined at 300℃ for 1h, ultrasonically cleaned for 15min, and electropolished in phosphoric acid ethanol solution at 20V for 30min;

[0051] S2: Place the zinc foil in S1 in a KHCO3 solution and apply voltage for 1 hour to oxidize the surface of the zinc foil to ZnO, then wash and dry.

[0052] S3: Place the zinc foil with ZnO grown in S2 in an oil bath containing hemin chloride and dimethylimidazole solution at 75°C for 24-48 hours, clean and dry, and then gradually increase the temperature to 900°C in an argon environment, keep the temperature for 1 hour, and cool naturally to obtain a Fe-N / C catalyst.

[0053] Example 3

[0054] As described in this embodiment, a method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film is as follows:

[0055] S1: Growing high-quality, self-supporting single-walled carbon nanotube films using floating catalyst chemical vapor deposition. Collecting 30-minute-thick films, the films were directly torn off for use in the reaction.

[0056] S2: The single-walled carbon nanotube film in S1 is rolled with the zinc sheet to form a Zn / SWCNT / Zn structure, then calcined in air, immersed in oxidation, and ZnO is formed on the surface of the single-walled carbon nanotube film. The ZIF structure is then self-assembled in a solution containing hemin chloride and dimethylimidazole, and then washed and dried.

[0057] S3: The flexible film with ZIF grown in S2 was gradually heated to 900°C in an argon environment, kept warm for 1 hour, and cooled naturally to obtain an integrated Fe-N / SWCNT catalyst.

[0058] Example 4

[0059] Through SEM characterization, we can see that a1, a2, b1, b2, c1 and c2 in Figure 2 correspond to single-walled carbon nanotubes, after electrodeposition of pyrrole and after the growth of ZnO self-assembled zeolite imidazole ZIF structure, which proves the successful development of flexible single-walled carbon nanotubes through ZnO derivatization of ZIF structure.

[0060] Through the optical schematic diagram, Figure 3 shows that the catalyst prepared by growing ZnO-derived zeolite imidazole ZIF structure loaded with metal on flexible carbon nanotube film still has mechanical flexibility.

[0061] Through TEM characterization, we can see that Figure 4 a, b and c show that the original ZIF structure is still maintained on the flexible single-walled carbon nanotubes, which proves that the ZIF structure is successfully grown on the flexible single-walled carbon nanotubes and a flexible integrated single-atom catalyst is prepared.

[0062] Through XRD characterization, Figure 5 shows the XRD pattern of pyrrole electrodeposited on single-walled carbon nanotubes, simulating the charging growth of ZnO, which proves the successful growth of ZnO on flexible single-walled carbon nanotubes.

[0063] Through spherical aberration characterization, the small bright spots seen in Figure 6 can prove that the flexible carbon nanotube film is used to prepare single-atom catalysts through the ZnO-derived ZIF structure.

[0064] The ORR performance of the sample obtained in Example 1 was tested in the following steps:

[0065] S1: The film obtained in Example 1 was cut into a 2*2 mm square shape and directly attached to a disk electrode for RDE testing.

[0066] S2: The operating voltage of the ORR test is 0.2 to -1 V, and the scan rate is 5 mV / s.

[0067] S3: The test results show that the half-wave potential of Fe-NCl / PC / SWCNT thin film catalyst is 0.82V, which is comparable to the performance of commercial Pt / C (half-wave potential 0.83V). Figure 7 shown.

[0068] S4: The Fe-NCl / PC / SWCNT film was subjected to a 5000-cycle CV cycle test, and the performance only decayed by 6mV. The performance curves before and after the cycle were basically consistent. Figure 8 shown.

[0069] S5: Fe-NCl / PC / SWCNT thin film catalyst was assembled and tested in a zinc-air battery, and the power density was able to reach 220.8mW / cm 2 >140.3mW / cm 2 (Pt / C), e.g. Figure 9 As shown. Specific capacity 713.8mAh / g> 664.4mAh / g (Pt / C). Figure 10 shown.

[0070] Example 5

[0071] The ORR performance of the sample obtained in Example 2 was tested in the following steps:

[0072] S1: The Fe-N / C catalyst obtained in Example 2 was prepared into a 5 mg / ml Nafion solution (5 wt.%) and coated on a disk electrode for RDE testing.

[0073] S2: The operating voltage of the ORR test is 0.2 to -1 V, and the scan rate is 5 mV / s.

[0074] S3: The test results show that the half-wave potential of the Fe-N / C catalyst is 0.8V. Figure 11 shown.

[0075] Example 6:

[0076] The ORR performance of the sample obtained in Example 3 was tested in the following steps:

[0077] S1: The film obtained in Example 3 was cut into a 2*2 mm square shape and directly attached to a disk electrode for RDE testing.

[0078] S2: The operating voltage of the ORR test is 0.2 to -1 V, and the scan rate is 5 mV / s.

[0079] S3: The test results show that the half-wave potential of Fe-N / SWCNT thin film catalyst is 0.81V. Figure 12 shown.

[0080] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film, characterized in that: The following steps are involved: S1: taking an integrated substrate material, wherein the integrated substrate material is selected from single-walled carbon nanotube film, carbon cloth, carbon paper, zinc sheet or nickel foam; S2: growing a ZnO array on the integrated substrate material by electrodeposition, chemical growth or physical extrusion; S3: placing the integrated substrate material with the ZnO array in a solution containing 2-methylimidazole and a metal source to generate a zeolitic imidazole ZIF structure through self-assembly, so that the metal is embedded in the ZIF framework; S4: thermally decomposing the product of step S3 under an inert atmosphere to obtain a metal-loaded ZnO-derived ZIF structure catalyst.

2. The method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film according to claim 1, characterized in that: In step S1, the single-walled carbon nanotube film is prepared by a floating catalyst chemical vapor deposition method, the collection time is 15 to 30 minutes, and the film thickness is 0.25 to 0.5 mm.

3. The method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film according to claim 1, characterized in that: In step S2, the electrochemical deposition method uses an electrolyte containing 6M potassium hydroxide and 0.2M zinc acetate to electrochemically deposit a ZnO array on the substrate surface by simulating the charging process of a zinc-air battery.

4. The method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film according to claim 1, characterized in that: In the step S2, the integrated base material and the zinc sheet are compounded by a roller press using a physical extrusion method and then oxidized to form a ZnO array.

5. The method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film according to claim 1, characterized in that: In step S3, the self-assembly reaction time is 12 to 48 hours; and the metal source is at least one of hemin, cobalt salt, or nickel salt.

6. The method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film according to claim 1, characterized in that: In step S4, the temperature of the pyrolysis treatment is 900-1000° C., and the holding time is 1-2 hours; the inert atmosphere is argon.

7. The method for preparing a ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film according to claim 1, characterized in that: The metal is embedded in the ZIF framework in the form of a single atom, and the metal is selected from at least one of iron, cobalt or nickel.

8. A ZnO-derived zeolite imidazole (ZIF) structure-supported metal catalyst for the growth of a flexible carbon nanotube film prepared by the method according to any one of claims 1 to 7, characterized in that: The catalyst comprises an integrated substrate material, a ZnO array-derived ZIF structure and embedded metal active sites.

9. The ZnO-derived zeolite imidazole ZIF structure-supported metal catalyst for growing a flexible carbon nanotube film according to claim 8, characterized in that: The oxygen reduction reaction half-wave potential of the catalyst in a 0.1M HClO4 electrolyte is 0.8-0.82V, and the performance attenuation after 5000 cycles is ≤6mV.

10. Use of the catalyst according to claim 8 or 9 as an electrode material in a zinc-air battery.

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