Method for manufacturing and transferring transfer-resistant metal nanostructure catalyst, and transfer-resistant metal nanostructure catalyst manufactured thereby

Abstract

The disclosed metal nanostructure catalyst is manufactured by: forming a nanostructure in which a plurality of metal nanowires including a metal are aligned on a substrate; forming a protective layer including an organic material on the nanostructure; forming a groove adjacent to the nanostructure on one surface of the substrate on which the nanostructure is formed; and applying an etchant onto one surface of the substrate so as to fill the groove, thereby separating the nanostructure from the substrate.

Description

Preparation and transfer method of a non-transferable metal nanostructure catalyst and the non-transferable metal nanostructure catalyst prepared thereby

[0001] The present invention relates to a method for preparing and transferring a metal nanostructure catalyst containing a metal, and to a metal nanostructure catalyst. More specifically, it relates to a method for preparing and transferring a metal nanostructure catalyst having a three-dimensional nanostructure used as a carbon dioxide reduction reaction catalyst, and to a metal nanostructure catalyst.

[0002] Globally, reducing carbon dioxide emissions is a long-standing challenge aimed at lowering dependence on petroleum resources and addressing environmental issues. Carbon dioxide can be converted into eco-friendly energy sources or chemical raw materials through reduction reactions. However, the development of high-efficiency and high-selectivity catalysts is essential for decomposing carbon dioxide, which is chemically very stable. Recently, transfer methods for metal nanostructure catalysts are being used to manufacture high-efficiency electrochemical nanocatalysts based on this foundation.

[0003] A nanocatalyst is formed on a gas diffusion layer (GDL) to evaluate the catalytic performance of the carbon dioxide reduction reaction. The gas diffusion layer is a type of carbon paper with a very rough surface and is coated with a polymer such as fluorene-based polytetrafluoroethylene (PTFE) for stable reaction in an aqueous electrolyte.

[0004] Meanwhile, in order to produce high-value compounds containing two or more carbon atoms in the carbon dioxide reduction reaction, copper (Cu), a metal material that is difficult to transfer, is essential as a catalytic material that has appropriate bonding energy with carbon and oxygen. Generally, when transferring a nano-catalyst grown on a substrate to a carbon electrode, a copper etching solution is used, which presents a problem in that it is difficult to use catalytic materials containing copper.

[0005] <Prior Art Literature>

[0006] (Patent Document 0001) Korean Registered Patent No. 10-25649987

[0007] (Patent Document 0002) Korean Registered Patent No. 10-1752605

[0008] (Patent Document 0003) Korean Registered Patent No. 10-2203640

[0009] One objective of the present invention is to provide a method for manufacturing a non-transferable metal nanostructure catalyst for realizing a high-efficiency catalyst.

[0010] Another objective of the present invention is to provide a method for transferring the metal nanostructure catalyst using the above manufacturing method.

[0011] Another objective of the present invention is to provide the metal nanostructure catalyst through the above manufacturing method and the above transfer method.

[0012] However, the objectives of the present invention are not limited to the objectives described above and may be expanded in various ways without departing from the spirit and scope of the present invention.

[0013] To achieve one objective of the present invention as described above, a method for manufacturing a non-transferable metal nanostructure catalyst according to one embodiment of the present invention comprises the steps of: forming a nanostructure in which a plurality of metal nanowires containing a metal are aligned on a substrate; forming a protective layer containing an organic material on the nanostructure; forming a groove adjacent to the nanostructure on one surface of the substrate on which the nanostructure is formed; and applying an etching solution to the one surface of the substrate to fill the groove, thereby separating the nanostructure from the substrate.

[0014] In one embodiment, in the step of separating the nanostructure from the substrate, a portion of the substrate in contact with the nanostructure may be removed through the etching solution.

[0015] In one embodiment, the nanostructure comprises copper (Cu), the substrate is a silicon wafer (Si wafer) substrate, and the etching solution may be an aqueous potassium hydroxide (KOH) solution.

[0016] In one embodiment, the substrate is a silicon oxide wafer (SiO₂). x The wafer is a substrate, and the etching solution may be a buffered oxide etchant (BOE).

[0017] In one embodiment, in the step of forming the groove adjacent to the nanostructure, the groove may be formed to surround at least a portion of the edge portion of the nanostructure on a plane.

[0018] In one embodiment, in the step of forming the groove adjacent to the nanostructure, the shortest distance between the groove and the boundary of the protective layer on a plane may be about 2 mm or less.

[0019] In one embodiment, the step of forming the nanostructure may include: forming an acrylic resin on a master mold having a plurality of recessed patterns formed thereon; separating the acrylic resin from the master mold to form a plurality of protruding patterns corresponding to the plurality of recessed patterns on the acrylic resin; forming a first nanometal line layer in which a plurality of metal nanowires are aligned on the plurality of protruding patterns of the acrylic resin; attaching the first metal nano line layer to the substrate and removing the acrylic resin from the first metal nano line layer; and stacking a second nanometal line layer containing a material different from the first nanometal line layer on the substrate alternately with the first nanometal line layer.

[0020] In one embodiment, each of the plurality of metal nanowires included in the first nano metal line layer may include gold (Au), and each of the plurality of metal nanowires included in the second nano metal line layer may include copper (Cu).

[0021] In one embodiment, the direction in which each of the plurality of metal nanowires included in the first nano metal wire layer extends and the direction in which each of the plurality of metal nanowires included in the second nano metal wire layer extends may form an angle of 80° to 90° in a plane.

[0022] In one embodiment, in the step of forming the protective layer, the protective layer may be formed by coating the nanostructure with a solution comprising a solvent having a volume ratio of acetone, toluene, and heptane of about 4:4:2 to about 4.5:4.5:1 and an acrylic resin having a weight ratio of about 3 wt% to about 5 wt%.

[0023] In one embodiment, the protective layer may comprise at least one material selected from the group consisting of polymethyl methacrylate (PMMA), methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, and cellulose acetate.

[0024] In one embodiment, the method for transferring a metal nanostructure catalyst using nano-transfer printing, which is performed between the step of forming the nanostructure and the step of forming the groove, may further include the step of performing heat treatment on the nanostructure.

[0025] In one embodiment, in the step of performing the heat treatment, the heat treatment may be performed for about 5 minutes to about 2 hours at a temperature range of about 500°C to about 700°C.

[0026] To achieve another objective of the present invention as described above, a transfer method for a non-transferable metal nanostructure catalyst according to one embodiment of the present invention comprises the steps of: forming a nanostructure in which a plurality of metal nanowires containing a metal are aligned on a substrate; forming a protective layer containing an organic material on the nanostructure; forming a groove adjacent to the nanostructure on one surface of the substrate on which the nanostructure is formed; applying an etching solution to fill the groove to separate the nanostructure from the substrate; and attaching the separated nanostructure to a transfer target substrate.

[0027] In one embodiment, the step of attaching the nanostructure to the transfer target substrate may include the step of introducing the nanostructure into a deionized water (DI water) solution, the step of introducing the transfer target substrate into the deionized water solution so that the transfer target substrate comes into contact with the nanostructure from below the nanostructure, and the step of drying the nanostructure and the transfer target substrate.

[0028] In one embodiment, the step of attaching the nanostructure to the transfer target substrate may further include the step of surface treating the transfer target substrate so that hydroxyl groups are formed on the surface of the transfer target substrate before immersing the transfer target substrate in the deionized water solution.

[0029] In one embodiment, the nanostructure comprises copper (Cu), the substrate is a silicon wafer (Si wafer) substrate, and the etching solution may be an aqueous potassium hydroxide (KOH) solution.

[0030] In one embodiment, the substrate is a silicon oxide wafer (SiO₂). x The wafer is a substrate, and the etching solution may be a buffered oxide etchant (BOE).

[0031] In one embodiment, in the step of forming the groove adjacent to the nanostructure, the groove may be formed to completely surround the boundary of the protective layer on a plane.

[0032] To achieve another objective of the present invention as described above, a metal nanostructure catalyst according to one embodiment of the present invention comprises a first metal nanowire layer containing copper (Cu) and comprising a plurality of metal nanowires spaced apart from each other in a planar plane, and a second metal nanowire layer containing gold (Au) and comprising a plurality of metal nanowires spaced apart from each other in a planar plane. A plurality of the first metal nanowire layer and the second metal nanowire layer are alternately stacked.

[0033] In a method for manufacturing and transferring a metal nanostructure catalyst containing a metal according to embodiments of the present invention, a groove adjacent to the nanostructure is formed on one surface of a substrate, and an etching solution filling the groove can be applied. Accordingly, even without placing the substrate and the nanostructure into a container containing the etching solution, the etching solution diffusing along the groove can remove a portion of the substrate in contact with the nanostructure, thereby allowing the substrate to be easily removed from the nanostructure. Therefore, the process time and cost of obtaining the nanostructure used in a metal catalyst structure for carbon dioxide reduction can be reduced.

[0034] In addition, since the substrate can be easily removed by forming the groove, the substrate can be a metal or metal oxide containing copper, which is difficult to transfer. Accordingly, there are no restrictions on the type of substrate for manufacturing the metal catalyst structure, and since an etching solution for etching copper is not used, the nanostructure can contain copper. Therefore, the metal catalyst structure with high efficiency and high selectivity can be easily manufactured.

[0035] In addition, if the transfer target substrate is a hydrophobic gas diffusion layer, a surface treatment can be performed so that the surface of the transfer target substrate has hydroxyl groups. Accordingly, the nanostructure can be easily attached to or transferred to the gas diffusion layer.

[0036] In addition, since there are no significant restrictions on the type of substrate to be used to manufacture the metal catalyst structure, heat treatment can be performed on the nanostructure before forming the groove. Accordingly, the crystallinity of the nanostructure can be improved. Therefore, the performance of the metal catalyst structure for carbon dioxide reduction manufactured from the nanostructure can be improved.

[0037] However, the effects of the present invention are not limited to the effects described above, and may be extended in various ways without departing from the spirit and scope of the present invention.

[0038] FIG. 1 is a flowchart illustrating a method for transferring a metal nanostructure catalyst according to one embodiment of the present invention.

[0039] Figure 2 is a diagram illustrating a method for transferring the metal nanostructure catalyst of Figure 1.

[0040] FIG. 3 is a plan view illustrating the step of forming a groove on one surface of the substrate of FIG. 1.

[0041] Figure 4 is a flowchart illustrating a method for forming a nanostructure on the substrate of Figure 1.

[0042] Figure 5 is a diagram illustrating a method for forming a nanostructure on the substrate of Figure 1.

[0043] FIG. 6 is a diagram illustrating a method for transferring a metal nanostructure catalyst according to another embodiment of the present invention.

[0044] FIG. 7 is a diagram illustrating a method for transferring a metal nanostructure catalyst according to another embodiment of the present invention.

[0045] Figure 8 is a graph showing the electrical characteristics of a prepared example prepared according to the method of preparing and transferring a metal nanostructure catalyst of the present invention.

[0046] Figure 9 is a graph showing the carbon dioxide reduction efficiency of the manufacturing example of Figure 8.

[0047] With respect to the embodiments of the present invention disclosed in the text, specific structural or functional descriptions are provided merely for the purpose of explaining the embodiments of the present invention, and the embodiments of the present invention may be implemented in various forms and should not be interpreted as being limited to the embodiments described in the text.

[0048] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0049] Terms such as "first," "second," etc., may be used to describe various components, but said components should not be limited by said terms. These terms may be used for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0050] When it is stated that one component is "connected" or "connected" to another component, it should be understood that while it may be directly connected or connected to that other component, there may also be other components in between. Conversely, when it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between. Other expressions describing the relationship between components, such as "between" and "exactly between," or "adjacent to" and "directly adjacent to," should be interpreted in the same way.

[0051] The terms used in this application are used merely to describe specific embodiments and are not intended to limit the invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "comprising" or "having" are intended to specify the existence of the described features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0052] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application.

[0053] Meanwhile, if an embodiment can be implemented differently, a function or operation specified within a particular block may occur differently from the order specified in the flowchart. For example, two consecutive blocks may actually be executed substantially simultaneously, or, depending on the related function or operation, said blocks may be executed in reverse order.

[0054] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. Identical components in the drawings are given the same reference numerals, and redundant descriptions of identical components are omitted.

[0055] FIG. 1 is a flowchart illustrating a method for transferring a metal nanostructure catalyst according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the method for transferring a metal nanostructure catalyst of FIG. 1. FIG. 3 is a plan view illustrating the step of forming a groove on one surface of a substrate of FIG. 1. FIG. 4 is a flowchart illustrating a method for forming a nanostructure on a substrate of FIG. 1. FIG. 5 is a diagram illustrating a method for forming a nanostructure on a substrate of FIG. 1.

[0056] Referring to FIGS. 1 to 5, a method for transferring a metal nanostructure catalyst (S1) according to one embodiment of the present invention may include the steps of forming a nanostructure (20) on a substrate (10) (S10), forming a groove (40) on one surface of the substrate (10) (S20), separating the nanostructure (20) from the substrate (10) using an etching solution (50) (S30), and attaching the nanostructure (20) to a transfer target substrate (60) (S40).

[0057] That is, the transfer method (S1) may be a concept that includes a method for manufacturing a nanostructure (20). In particular, the step of forming a nanostructure (20) on a substrate (10) (S10), the step of forming a groove (40) on one side of the substrate (10) (S20), and the step of separating the nanostructure (20) from the substrate (10) using an etching solution (50) (S30) may be referred to as a method for manufacturing a metal nanostructure catalyst.

[0058] In this specification, the nanostructure (20) may be referred to as a metal nanostructure catalyst.

[0059] The step (S10) of forming a nanostructure (20) may include the step (S110) of forming a replica mold (80) on one side of a master mold (70) having a plurality of recessed patterns formed thereon, the step (S120) of separating the replica mold (80) from the master mold (70) and forming a plurality of protruding patterns on one side of the replica mold (80), the step (S130) of forming a first metal nanowire layer (22) on the protruding patterns of the replica mold (80), the step (S140) of attaching the first metal nanowire layer (22) to a substrate (10) and removing the replica mold (80), the step (S150) of forming a nanostructure (20) by alternately stacking the first metal nanowire layer (22) and the second metal nanowire layer (24), and the step (S160) of forming a protective layer (30) on the nanostructure (20).

[0060] In the step (S110) of forming a replica mold (80) on one surface of a master mold (70) in which the plurality of indentation patterns are defined, the master mold (70) may be manufactured through a reactive ion etching process after a photolithography process. For example, the master mold (70) may have a plurality of indentation patterns (e.g., engravings) formed through a photolithography process. In one embodiment, each of the plurality of indentation patterns defined in the master mold (70) may have a width of about 20 nm to about 200 nm. For example, each of the plurality of indentation patterns may be formed elongated in one direction to control orientation.

[0061] In one embodiment, one surface of the master mold (70) may be spin-coated with a hydroxyl-terminated polymer. For example, the polymer may be hydroxyl-terminated PDMS (polydimethylsiloxane PDMS) or hydroxyl-terminated PS (polystyrene). However, the type of polymer coated on the master mold (70) according to the embodiments of the present invention is exemplary and is not necessarily limited thereto.

[0062] In one embodiment, the transfer method (S1) of the metal nanostructure catalyst may further include the step of annealing the master mold (70) coated with the polymer. In one embodiment, the process of annealing the master mold (70) may be performed at approximately 200°C for approximately 2 hours, and after the annealing process is performed, the polymer not attached to the one surface of the master mold (70) may be washed with heptane.

[0063] In the step (S120) of separating a replica mold (80) from a master mold (70) to form a plurality of protruding patterns on one side of the replica mold (80), when the replica mold (80) coated on the one side of the master mold (70) is separated from the master mold (70), the polymer can be used to lower the surface energy so that the replica mold (80) is completely separated from the plurality of indented patterns.

[0064] In one embodiment, the polymer may have a weight ratio of about 0.5 wt% to about 5 wt% in an organic solvent. Preferably, the polymer may have a weight ratio of about 1 wt% to about 2 wt% in the organic solvent. If the weight ratio of the polymer is less than about 0.5 wt%, the replication mold (80) cannot be completely separated from the master mold (70), and if it exceeds about 5 wt%, the polymer that has not reacted with the master mold (70) may not be completely removed.

[0065] A replica mold (80) may be formed on one surface of the master mold (70). For example, the one surface of the master mold (70) may be coated with the replica mold (80) after being spin-coated with the polymer. In one embodiment, the replica mold (80) may include an acrylic resin. In one embodiment, the replica mold (80) may include polymethyl methacrylate (PMMA), methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, cellulose acetate, etc. These may be used alone or in combination with each other.

[0066] In one embodiment, the replication mold (80) may have a weight ratio of about 1 wt% to about 10 wt% in a solvent comprising polymethyl methacrylate, acetone, heptane, and toluene. Preferably, the replication mold (80) may have a weight ratio of about 3 wt% to about 5 wt% in the solvent. If the replication mold (80) has a weight ratio of less than 1 wt%, the plurality of protruding patterns having a shape corresponding to the shape of the plurality of recessed patterns of the master mold (70) may not be formed, and if it has a weight ratio of more than 10 wt%, it may be difficult to remove the replication mold (80) from the master mold (70).

[0067] In the step (S120) of separating the replica mold (80) from the master mold (70) and forming the plurality of protruding patterns on one surface of the replica mold (80), the replica mold (80) may be separated from the master mold (70) by attaching an adhesive tape to the replica mold (80). In one embodiment, the adhesive tape may include polyimide (PI). However, the type of adhesive tape attached to the replica mold (80) according to the embodiments of the present invention is exemplary and is not necessarily limited thereto.

[0068] For example, after the adhesive tape is attached to the other side opposite to the one side facing the master mold (70) of the replication mold (80), the replication mold (80) can be pulled to separate the replication mold (80) from the master mold (70). Specifically, after attaching the polyimide tape to the other side of the replication mold (80), if the tape is pulled as if peeling it off, the replication mold (80) is moved to the side of the tape and separated. Accordingly, the plurality of protruding patterns corresponding to the plurality of recessed patterns of the master mold (70) can be formed on the one side of the replication mold (80). In one embodiment, the plurality of protruding patterns may be spaced apart from each other on a plane. For example, the plurality of protruding patterns may be arranged on a plane with a spacing of about 100 nm to about 300 nm from each other. Preferably, the spacing at which the plurality of protruding patterns are arranged may be about 150 nm to about 250 nm. More preferably, the spacing between the plurality of protruding patterns may be about 200 nm.

[0069] In the step (S130) of forming a first metal nanowire layer (22) on the protruding patterns of the replication mold (80), a metal material can be deposited toward one side of the replication mold (80). For example, after positioning the replication mold (80) such that the direction in which the metal material is deposited and the one side of the replication mold (80) have an angle of inclination, the metal material can be deposited onto the protruding patterns using an e-beam evaporator. Accordingly, a first metal nanowire layer (22) containing the metal material can be formed on the protruding patterns.

[0070] In one embodiment, a plurality of metal nanowires may be aligned in the first metal nanowire layer (22). In one embodiment, the first metal nanowire layer (22) may include the plurality of metal nanowires spaced apart from each other in a plane. Specifically, the plurality of metal nanowires may be arranged spaced apart in a second direction that extends in a first direction parallel to one surface of the replication mold (80) and intersects the first direction. For example, the first direction may be perpendicular to the second direction.

[0071] The first metal nanowire layer (22) has a relatively smaller deposition thickness than when manufacturing a general metal thin film, so that a higher-order crystal plane can be included on the catalytic active surface, thereby suppressing the hydrogen generation reaction and increasing the CO selectivity in the carbon dioxide reduction reaction.

[0072] In one embodiment, the metal material may include gold (Au), silver (Ag), tin (Sn), copper (Cu), etc. In one embodiment, the deposition rate of the metal material is about 0.5 / s to about 2.0 It may be / s. Preferably, the deposition rate of the metal material is about 1.0 / s to about 1.9 It may be / s. More preferably, the deposition rate of the metal material is about 1.5 / s could be.

[0073] In one embodiment, the angle of inclination may be about 80° to about 90°. Preferably, the angle of inclination may be about 83° to about 87°. More preferably, the angle of inclination may be about 85°.

[0074] In one embodiment, the first metal nanowire layer (22) formed on one surface of the replication mold (80) may have a single-layer structure. However, the first metal nanowire layer (22) according to the embodiments of the present invention is not necessarily limited thereto, and the first metal nanowire layer (22) formed on one surface of the replication mold (80) may have a multi-layer structure.

[0075] In the step (S140) of attaching the first metal nanowire layer (22) to the substrate (10) and removing the replication mold (80), after attaching the first metal nanowire layer (22) to the substrate (10), the replication mold (80) may be exposed to organic solvent vapor. In one embodiment, the organic solvent vapor may include heptane, acetone, etc. Specifically, to weaken the adhesion between the tape and the replication mold (80), organic solvent vapor maintained at about 45°C to about 90°C for at least 10 minutes may be provided to the first metal nanowire layer (22) deposited on the replication mold (80) for about 10 seconds to about 40 seconds. Immediately after the first metal nanowire layer (22) is exposed to the vapor, the first metal nanowire layer (22) deposited on the replication mold (80) may be attached to the substrate (10) and the tape may be removed. Accordingly, the first metal nanowire layer (22) and the replication mold (80) can be transferred to the substrate (10).

[0076] After the first metal nanowire layer (22) and the replication mold (80) are transferred to the substrate (10), the replication mold (80) can be removed to obtain the first metal nanowire layer (22) having an aligned pattern. In one embodiment, the first metal nanowire layer (22) can be transferred onto one surface of the substrate (10), and the plurality of metal nanowires included in the first metal nanowire layer (22) can be arranged on the one surface of the substrate (10) by extending in the first direction and being spaced apart in the second direction. In one embodiment, the replication mold (80) can be removed using an organic solvent such as toluene.

[0077] In one embodiment, the substrate (10) is a silicon wafer (Si wafer) or silicon oxide (SiO₂). x It may be a wafer. However, the type of substrate (10) according to the embodiments of the present invention is not necessarily limited thereto.

[0078] In one embodiment, the thickness of the substrate (10) may be about 500 nm to about 550 nm. For example, if the substrate (10) is a silicon wafer (Si wafer) substrate, the thickness of the substrate (10) may be about 500 nm to about 550 nm. As another example, the substrate (10) may be silicon oxide (SiO₂). x In the case where the substrate is a wafer, the thickness of the substrate (10) may be approximately 505 nm to approximately 545 nm. Specifically, the substrate (10) is silicon oxide (SiO₂). x In the case of a wafer substrate, the substrate (10) may include a silicon oxide layer and a silicon wafer layer. The silicon oxide layer may be about 300 nm or less.

[0079] In the step (S150) of forming a nanostructure by alternately stacking a first metal nanowire layer (22) and a second metal nanowire layer (24), a second metal nanowire layer (24) may be formed on the first metal nanowire layer (22) formed on the substrate (10). Specifically, the second metal nanowire layer (24) is formed by depositing a metal material contained in the second metal nanowire layer (24) onto a replication mold (80), and the surface of the replication mold (80) on which the second metal nanowire layer (24) is formed may be attached to the first metal nanowire layer (22). Subsequently, the replication mold (80) may be removed with the organic solvent so that the first metal nanowire layer (22) and the second metal nanowire layer (24) may be formed by sequentially and alternately stacking on the substrate (10).

[0080] In one embodiment, a plurality of metal nanowires may be aligned in the second metal nanowire layer (24). In one embodiment, the second metal nanowire layer (24) may include the plurality of metal nanowires comprising a metal material. For example, the metal material may include gold (Au), silver (Ag), tin (Sn), copper (Cu), etc.

[0081] In one embodiment, the second metal nanowire layer (24) may contain a material different from the first metal nanowire layer (22). For example, if the first metal nanowire layer (22) contains gold (Au), the second metal nanowire layer (24) may contain copper (Cu). As another example, if the first metal nanowire layer (22) contains copper (Cu), the second metal nanowire layer (24) may contain gold (Au). However, the materials included in the first metal nanowire layer (22) and the second metal nanowire layer (24), respectively, according to the embodiments of the present invention are exemplary and are not necessarily limited thereto.

[0082] In another embodiment, the first metal nanowire layer (22) and the second metal nanowire layer (24) may contain the same material. For example, the first metal nanowire layer (22) and the second metal nanowire layer (24) may both contain gold (Au) and copper (Cu).

[0083] After the second metal nanowire layer (24) is formed, the first metal nanowire layer (22) and the second metal nanowire layer (24) can be alternately stacked. Accordingly, a nanostructure (20) in which the first metal nanowire layer (22) and the second metal nanowire layer (24) are alternately stacked can be manufactured. The nanostructure (20) may be a catalyst to be used in a carbon dioxide reduction reaction.

[0084] In one embodiment, the direction in which the metal nanowires included in the first metal nanowire layer (22) extend and the direction in which the metal nanowires included in the second metal nanowire layer (24) extend may intersect each other. For example, the angle formed by the direction in which the metal nanowires included in the first metal nanowire layer (22) extend and the direction in which the metal nanowires included in the second metal nanowire layer (24) extend may be about 70° to about 90°. Preferably, the angle formed by the direction in which the metal nanowires included in the first metal nanowire layer (22) extend and the direction in which the metal nanowires included in the second metal nanowire layer (24) extend may be about 80° to about 90°.

[0085] Accordingly, sufficient space can be secured between metal nanowires arranged in different layers, and the secured space is filled with an electrolyte to increase the utilization efficiency of the catalyst and allow reactants and products within the catalyst to move easily. In addition, the local pH of the electrode surface is increased by the space secured within the manufactured nanostructure (20), thereby suppressing the hydrogen generation reaction and increasing CO selectivity.

[0086] In one embodiment, the thickness of each of the first metal nanowire layer (22) and the second metal nanowire layer (24) may be about 30 nm or more and about 100 nm. Preferably, the thickness of each of the first metal nanowire layer (22) and the second metal nanowire layer (24) may be about 30 nm or more and about 50 nm. In one embodiment, the number of layers in which the first metal nanowire layer (22) and the second metal nanowire layer (24) are stacked within the nanostructure (20) may be about 10 or more and about 50 or more. Preferably, the number of layers in which the first metal nanowire layer (22) and the second metal nanowire layer (24) are stacked within the nanostructure (20) may be about 15 or more and about 30 or more. However, the number of layers in which the first metal nanowire layer (22) and the second metal nanowire layer (24) are stacked within the nanostructure (20) according to the embodiments of the present invention is not necessarily limited thereto.

[0087] In the step (S160) of forming a protective layer (30) on a nanostructure (20), the protective layer (30) may be coated on the top of the nanostructure (20). For example, the protective layer (30) may be spin-coated on the top and sides of the nanostructure (20). In one embodiment, the protective layer (30) may include an organic material. For example, the organic material may include an acrylic resin. For example, the acrylic resin may include polymethyl methacrylate, methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, etc. These may be used alone or in combination with each other.

[0088] In one embodiment, the protective layer (30) may be formed by spin-coating a solution containing the acrylic resin. In one embodiment, the solution may be in a state where the acrylic resin is contained in a solvent containing acetone, toluene, and heptane. For example, the acrylic resin contained in the solution may have a weight ratio of about 3 wt% to about 5 wt%. Preferably, the acrylic resin contained in the solution may have a weight ratio of about 4 wt%. For example, the volume ratio of acetone, toluene, and heptane in the solution may be about 4:4:2 to about 4.5:4.5:1.

[0089] In one embodiment, the thickness of the protective layer (30) may be about 100 nm or more to about 400 nm. Preferably, the thickness of the protective layer (30) may be about 200 nm or more to about 300 nm.

[0090] In the step (S20) of forming a groove (40) on one surface of the substrate (10), the groove (40) may be formed in a portion adjacent to the nanostructure (20) of the substrate (10). In one embodiment, the groove (40) may have a shape of an indentation that is recessed in the thickness direction of the substrate (10). In one embodiment, the groove (40) may be formed by causing fine damage on one surface of the substrate (10) using a cutting device such as a diamond cutter. However, the device for forming the groove (40) according to the embodiments of the present invention is exemplary and is not necessarily limited thereto.

[0091] In one embodiment, the groove (40) may surround at least a portion of the nanostructure (20) and the protective layer (30) on a flat surface. For example, the groove (40) may surround the protective layer (30) entirely on a flat surface. Specifically, the groove (40) may be formed by moving the diamond cutter along the boundary of the protective layer (30) to create friction on the surface of the substrate (10). When the groove (40) does not surround the protective layer (30) entirely but partially surrounds it, the speed at which the nanostructure (20) is separated from the substrate (10) using the etching solution (50) in step (S30) may be relatively slow.

[0092] In one embodiment, on one surface of the substrate (10), the groove (40) may be formed at a location adjacent to the nanostructure (20). For example, the groove (40) may be adjacent to the edge portion of the nanostructure (20). In one embodiment, the thickness of the groove (40) may be about 50 μm or less.

[0093] In one embodiment, the shortest distance between the boundary of the protective layer (30) and the groove (40) on a flat surface may be about 2 mm or less. If the shortest distance between the boundary of the protective layer (30) and the groove (40) exceeds 2 mm, the speed at which the nanostructure (20) is separated from the substrate (10) in the step (S30) of separating the nanostructure (20) from the substrate (10) using an etching solution (50) may be relatively slow. Additionally, the closer the shortest distance between the boundary of the protective layer (30) and the groove (40) on a flat surface is to 0, the faster the speed at which the nanostructure (20) is separated from the substrate (10) in the step (S30) of separating the nanostructure (20) from the substrate (10) using an etching solution (50) may be relatively fast.

[0094] In the step (S30) of separating the nanostructure (20) from the substrate (10) using the etching solution (50), the etching solution (50) may be applied toward the one side of the substrate (10). Specifically, the etching solution (50) may fill the portion of the substrate (10) that is recessed by the groove (40), and accordingly, the etching solution (50) may remove the interior of the substrate (10). In other words, the groove (40) may be formed so that the etching solution (50) can rapidly diffuse into the interior of the substrate (10) to easily separate the nanostructure (20) from the substrate (10).

[0095] In one embodiment, the etching solution (50) may be a buffered oxide etch (BOE) solution or an aqueous potassium hydroxide (KOH) solution. For example, if the substrate (10) is a silicon oxide wafer, the etching solution (50) may be a BOE solution. In another example, if the substrate (10) includes a silicon wafer, the etching solution (50) may be an aqueous potassium hydroxide (KOH) solution. Specifically, the aqueous potassium hydroxide (KOH) solution may have a weight ratio of about 20 wt% to about 40 wt%. Preferably, the aqueous potassium hydroxide (KOH) solution may have a weight ratio of about 30 wt% to about 35 wt%. However, the type of etching solution (50) according to the embodiments of the present invention is exemplary and is not necessarily limited thereto. In one embodiment, the volume of the etching solution (50) may be about 3 ml or more. Preferably, the volume of the etching solution (50) can be about 5 ml.

[0096] A portion of the substrate (10) adjacent to the edge portion of the nanostructure (20) covered by the protective layer (30) is preferentially etched through the etching solution (50), and subsequently, the etching solution (50) diffuses from the groove (40) to remove the portion of the substrate (10) in contact with the nanostructure (20). Accordingly, the nanostructure (20) separated from the substrate (10) floats on the etching solution (50), and the nanostructure (20) can be retrieved from the etching solution (50).

[0097] In the step (S40) of attaching the nanostructure (20) to the transfer target substrate (60), the nanostructure (20) separated from the substrate (10) can be obtained and the nanostructure (20) can be introduced into a deionized water (DI water) solution. The nanostructure (20) can float in the deionized water solution.

[0098] The nanostructure (20) and the transfer target substrate (60) can be brought into contact within the above deionized water solution. For example, the transfer target substrate (60) can be introduced below the nanostructure (20) floating in the above deionized water solution to bring the nanostructure (20) and the transfer target substrate (60) into contact. In one embodiment, the transfer target substrate (60) may be a metal electrode, an exchange membrane, etc. included in a battery for a carbon dioxide reduction reaction.

[0099] After the nanostructure (20) and the transfer target substrate (60) come into contact with each other, the nanostructure (20) and the transfer target substrate (60) can be dried. For example, a blower can be used to remove moisture present between the nanostructure (20) and the transfer target substrate (60), and accordingly, the nanostructure (20) can be completely attached (or transferred) to the transfer target substrate (60).

[0100] In one embodiment, after the step (S40) of attaching the nanostructure (20) to the transfer target substrate (60), the protective layer (30) covering the nanostructure (20) may be removed. For example, the protective layer (30) may be removed using an organic solvent such as toluene. Accordingly, a metal catalyst structure or a metal catalyst electrode having a three-dimensional nanostructure transferred to the transfer target substrate (60) may be manufactured.

[0101] As described above, in a transfer method (S1) of a metal nanostructure catalyst according to one embodiment of the present invention, a groove (40) adjacent to the nanostructure (20) is formed on one surface of a substrate (10), and an etching solution that fills the groove (40) can be applied. Accordingly, even without placing the substrate (10) and the nanostructure (20) into a container containing the etching solution, the etching solution diffusing along the groove (40) can remove a portion of the substrate (10) in contact with the nanostructure (20), thereby allowing the substrate (10) to be easily removed from the nanostructure (20). Therefore, the process time and cost of obtaining the nanostructure (20) used in the metal catalyst structure for carbon dioxide reduction can be reduced.

[0102] Additionally, since the substrate (10) can be easily removed by forming the groove (40), a substrate (10) of a metal or metal oxide containing copper can be used. Accordingly, there are no restrictions on the type of substrate (10) for manufacturing the metal catalyst structure, and since an etching solution for etching copper is not used, the nanostructure (20) can contain copper. Therefore, the metal catalyst structure with high efficiency and high selectivity can be easily manufactured.

[0103] In the present specification, the steps of forming a nanostructure (20) on a substrate (10) (S10), forming a groove (40) on one surface of the substrate (10) (S20), and separating the nanostructure (20) from the substrate (10) using an etching solution (50) (S30) may be referred to as a method for manufacturing a metal nanostructure catalyst.

[0104] FIG. 6 is a diagram illustrating a method for transferring a metal nanostructure catalyst according to another embodiment of the present invention.

[0105] The transfer method (S2) of a metal nanostructure catalyst described with reference to FIG. 6 may be substantially the same or similar as the transfer method (S1) of a metal nanostructure catalyst described with reference to FIG. 1 to 5, except that it further includes the step (S32) of surface treating a transfer target substrate (60). In the following, content that overlaps with the content described with reference to FIG. 1 to 5 may be omitted or briefly described.

[0106] Referring to FIGS. 2 to 6, a transfer method (S2) of a metal nanostructure catalyst according to another embodiment of the present invention may further include a step (S32) of surface treatment on a transfer target substrate (60). In one embodiment, the transfer target substrate (60) may be a highly hydrophobic gas diffusion layer (GDL) included in a battery for a carbon dioxide reduction reaction. For example, the highly hydrophobic gas diffusion layer may be carbon paper, polytetrafluoroethylene (PTFE), etc.

[0107] In one embodiment, in the step (S32) of surface treatment on the transfer target substrate (60), a surface treatment such as an oxygen plasma process may be performed on the gas diffusion layer so that hydroxyl groups are formed on the transfer target substrate (60). A hydrophilic polymer brush may be coated on the transfer target substrate (60) after surface treatment. Subsequently, the transfer target substrate (60) is immersed in the deionized water solution to come into contact with the nanostructure (20), and the nanostructure (20) and the transfer target substrate (60) are dried together so that the nanostructure (20) can be completely attached (or transferred) to the transfer target substrate (60). Subsequently, a protective layer (30) covering the nanostructure (20) may be removed. Accordingly, a metal catalyst structure having a three-dimensional nanostructure transferred to the transfer target substrate (60) can be manufactured.

[0108] As described above, in a transfer method (S2) of a metal nanostructure catalyst according to one embodiment of the present invention, a groove (40) adjacent to the nanostructure (20) is formed on one surface of a substrate (10), and an etching solution that fills the groove (40) can be applied. Accordingly, even without placing the substrate (10) and the nanostructure (20) into a container containing the etching solution, the etching solution diffusing along the groove (40) can remove a portion of the substrate (10) in contact with the nanostructure (20), thereby allowing the substrate (10) to be easily removed from the nanostructure (20). Therefore, the process time and cost of obtaining the nanostructure (20) used in the metal catalyst structure for carbon dioxide reduction can be reduced.

[0109] Additionally, since the substrate (10) can be easily removed by forming the groove (40), a substrate (10) of a metal or metal oxide containing copper can be used. Accordingly, there are no restrictions on the type of substrate (10) for manufacturing the metal catalyst structure, and since an etching solution for etching copper is not used, the nanostructure (20) can contain copper. Therefore, the metal catalyst structure with high efficiency and high selectivity can be easily manufactured.

[0110] Additionally, if the transfer target substrate (60) is a gas diffusion layer having hydrophobicity, a surface treatment can be performed so that the surface of the transfer target substrate (60) has hydroxyl groups. Accordingly, the nanostructure (20) can be easily attached to or transferred to the gas diffusion layer.

[0111] In the present specification, the steps of forming a nanostructure (20) on a substrate (10) (S10), forming a groove (40) on one surface of the substrate (10) (S20), and separating the nanostructure (20) from the substrate (10) using an etching solution (50) (S30) may be referred to as a method for manufacturing a metal nanostructure catalyst.

[0112] FIG. 7 is a diagram illustrating a method for transferring a metal nanostructure catalyst according to another embodiment of the present invention.

[0113] The transfer method (S3) of a metal nanostructure catalyst described with reference to FIG. 7 may be substantially the same or similar as the transfer method (S1) of a metal nanostructure catalyst described with reference to FIG. 1 to 5, except that it further includes the step (S12) of performing heat treatment on the nanostructure (20). In the following, content that overlaps with the content described with reference to FIG. 1 to 5 may be omitted or briefly described.

[0114] Referring to FIGS. 2 to 5 and FIG. 7, a transfer method (S3) of a metal nanostructure catalyst according to another embodiment of the present invention may further include a step (S12) of performing heat treatment on a nanostructure (20) performed between the step (S10) of forming a nanostructure (20) on a substrate (10) and the step (S20) of forming a groove (40) on one surface of the substrate (10).

[0115] In the step (S12) of performing a heat treatment on a nanostructure (20), the heat treatment may be performed to crystallize the metal nanowires included in the nanostructure (20). In one embodiment, the heat treatment may be performed at about 400 °C to about 800 °C. Preferably, the heat treatment may be performed at about 500 °C to about 700 °C. In one embodiment, the heat treatment may be performed for about 5 minutes to about 3 hours. Preferably, the heat treatment may be performed for about 1 hour to about 2 hours. However, the time of performing the heat treatment according to the embodiments of the present invention is not necessarily limited thereto and may be performed for a longer time than 3 hours.

[0116] However, the transfer method (S3) of the metal nanostructure catalyst according to the embodiments of the present invention is not necessarily limited thereto, and the transfer method (S3) of the metal nanostructure catalyst may further include a step (S32) of surface treating the transfer target substrate (60) of FIG. 6.

[0117] As described above, in the transfer method (S3) of a metal nanostructure catalyst according to one embodiment of the present invention, a groove (40) adjacent to the nanostructure (20) is formed on one surface of the substrate (10), and an etching solution that fills the groove (40) can be applied. Accordingly, even without placing the substrate (10) and the nanostructure (20) into a container containing the etching solution, the etching solution diffusing along the groove (40) can remove a portion of the substrate (10) in contact with the nanostructure (20), thereby allowing the substrate (10) to be easily removed from the nanostructure (20). Therefore, the process time and cost of obtaining the nanostructure (20) used in the metal catalyst structure for carbon dioxide reduction can be reduced.

[0118] Additionally, since the substrate (10) can be easily removed by forming the groove (40), a substrate (10) of a metal or metal oxide containing copper can be used. Accordingly, there are no restrictions on the type of substrate (10) for manufacturing the metal catalyst structure, and since an etching solution for etching copper is not used, the nanostructure (20) can contain copper. Therefore, the metal catalyst structure with high efficiency and high selectivity can be easily manufactured.

[0119] In addition, since there are no significant restrictions on the type of substrate (10) to be used to manufacture the metal catalyst structure, heat treatment can be performed on the nanostructure (20) before forming the groove (40). Accordingly, the crystallinity of the nanostructure (20) can be improved. Therefore, the performance of the metal catalyst structure for carbon dioxide reduction manufactured from the nanostructure (20) can be improved.

[0120] In the present specification, the steps of forming a nanostructure (20) on a substrate (10) (S10), performing heat treatment on the nanostructure (20) (S12), forming a groove (40) on one surface of the substrate (10) (S20), and separating the nanostructure (20) from the substrate (10) using an etching solution (50) (S30) may be referred to as a method for manufacturing a metal nanostructure catalyst.

[0121] FIG. 8 is a graph showing the electrical characteristics of a preparation example prepared according to the method for preparing and transferring a metal nanostructure catalyst of the present invention. FIG. 9 is a graph showing the carbon dioxide reduction efficiency of the preparation example of FIG. 8.

[0122] In the following, the performance evaluation of the following manufacturing example is described to explain the effects of the present invention.

[0123] Preparation Example

[0124] Referring to FIGS. 8 and 9, a total of 20 layers of nanostructures were formed by alternately stacking copper nanowire layers containing copper (Cu) and gold nanowire layers containing gold (Au) by irradiating the deposition material toward the upper surface of the silicon wafer substrate such that the angle of incidence of the deposition material emitted from the electron beam evaporator (e-beam evaporator) and the angle formed by the upper surface of the silicon wafer substrate was 85°, the upper and side portions of the nanostructures were coated with a PMMA coating film, a groove was formed in the portion of the silicon wafer surrounding the boundary of the PMMA coating film on a flat surface, 30 wt% potassium hydroxide (KOH) was applied to separate the nanostructures from the silicon wafer, and the nanostructures were transferred onto a PiperION® exchange membrane to produce a metal nanostructure catalyst according to the above preparation example.

[0125] At this time, the width of the deposition material incident from the electron beam deposition machine is 30 nm, and the width of one nanowire included in each copper nanowire layer and gold nanowire layer deposited on the silicon wafer due to the inclined angle of the silicon wafer is 60 nm, and the spacing of nanowires placed in the same layer is 400 nm.

[0126] In a flow cell, the metal nanostructure catalyst in which the nanostructure according to the above manufacturing example is transferred to the exchange membrane, an electrolyte containing 1.0 M KHCO3 with a pH of 7.5 and bubbling carbon dioxide gas, a counter electrode made of nickel foam (Ni foam), and a reverse hydrogen electrode (RHE) are arranged as reference electrodes, and the metal nanostructure catalyst in which the nanostructure according to the above manufacturing example is transferred to the exchange membrane is used as a working electrode to change the voltage from 0V to -2V for 30 minutes, and the amount of carbon monoxide (CO) and hydrogen (H2) generated from the catalyst for 30 minutes is measured as shown in the current density graph against the voltage potential of the reference electrode and Figure 9.

[0127] As shown in Fig. 8, the intensity of the current density is proportional to the magnitude of the voltage potential of the reference electrode, and as shown in Fig. 9, at a potential of -0.8V, the ratio of the amount of carbon monoxide to the amount of total product, which indicates the degree of carbon dioxide reduction, was measured to be 92.5%. Accordingly, it can be confirmed that the metal nanostructure catalyst prepared according to the metal nanostructure catalyst preparation and transfer method according to the embodiments of the present invention and separated from the substrate has high selectivity and high efficiency in the carbon dioxide reduction reaction, despite containing copper (Cu), a non-transferable metal material.

[0128] A method for manufacturing a metal nanostructure catalyst according to exemplary embodiments of the present invention and a method for transferring a metal nanostructure catalyst including the same can be used as a catalyst for carbon dioxide reduction, a battery including the same, an electronic device, a plant, etc.

[0129] Although the present invention has been described above with reference to exemplary embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as set forth in the following claims.

[0130] <Explanation of Symbols>

[0131] 10: Substrate 20: Nanostructure

[0132] 22: First metal nanowire layer 24: Second metal nanowire layer

[0133] 30: Protective layer 40: Home

[0134] 50: Etching solution 60: Transfer target substrate

[0135] 70: Master mold 80: Replica mold

Claims

1. A step of forming a nanostructure in which a plurality of metal nanowires containing metal are aligned on a substrate; A step of forming a protective layer containing an organic material on the above nanostructure; A step of forming a groove adjacent to the nanostructure on one surface of the substrate on which the nanostructure is formed; and A method for manufacturing a metal nanostructure catalyst comprising the step of applying an etching solution onto one surface of the substrate to fill the grooves, thereby separating the nanostructure from the substrate.

2. In the step of separating the nanostructure from the substrate according to claim 1, A method for manufacturing a metal nanostructure catalyst characterized by removing a portion of the substrate in contact with the nanostructure through the etching solution.

3. In Paragraph 1, The above nanostructure contains copper (Cu), and The above substrate is a silicon wafer (Si wafer) substrate, and A method for manufacturing a metal nanostructure catalyst characterized in that the etching solution is an aqueous potassium hydroxide (KOH) solution.

4. In claim 1, the substrate is a silicon oxide wafer (SiO₂ x wafer) is a substrate, and A method for manufacturing a metal nanostructure catalyst characterized in that the above etching solution is a buffered oxide etchant (BOE).

5. In the step of forming the groove adjacent to the nanostructure in claim 1, A method for manufacturing a metal nanostructure catalyst, characterized in that the above groove is formed to completely surround the boundary of the protective layer on a flat surface.

6. In the step of forming the groove adjacent to the nanostructure in claim 1, A method for manufacturing a metal nanostructure catalyst characterized in that the shortest distance between the boundary of the groove and the protective layer on a plane is 2 mm or less.

7. In claim 1, the step of forming the nanostructure is, A step of forming an acrylic resin on a master mold having multiple indentation patterns formed thereon; A step of separating the acrylic resin from the master mold and forming a plurality of protruding patterns corresponding to the plurality of indented patterns on the acrylic resin; A step of forming a first nano metal line layer in which a plurality of metal nanowires are aligned on the plurality of protruding patterns of the acrylic resin; A step of attaching the first metal nanowire layer to the substrate and removing the acrylic resin from the first metal nanowire layer; and A method for manufacturing a metal nanostructure catalyst characterized by including the step of stacking a second nano metal line layer containing a material different from the first nano metal line layer on the substrate alternately with the first nano metal line layer.

8. In Paragraph 7, Each of the plurality of metal nanowires included in the first nano metal wire layer comprises gold (Au), and A method for manufacturing a metal nanostructure catalyst, characterized in that each of the plurality of metal nanowires included in the second nano metal wire layer comprises copper (Cu).

9. A method for manufacturing a non-transferable metal nanostructure catalyst according to claim 7, characterized in that the direction in which each of the plurality of metal nanowires included in the first nano metal wire layer extends and the direction in which each of the plurality of metal nanowires included in the second nano metal wire layer extends form an angle of 80° to 90° in a plane.

10. In the step of forming the protective layer according to claim 1, A method for manufacturing a non-transferable metal nanostructure catalyst, characterized in that the protective layer is formed by coating the nanostructure with a solution comprising a solvent having a volume ratio of acetone, toluene, and heptane of 4:4:2 to 4.5:4.5:1 and an acrylic resin having a weight ratio of 3 wt% to 5 wt%.

11. A method for preparing a metal nanostructure catalyst according to claim 1, wherein the protective layer comprises at least one material selected from the group consisting of polymethyl methacrylate (PMMA), methyl acrylate, ethyl acrylate, n-butyl acrylate, t-butyl acrylate, and cellulose acetate.

12. In Paragraph 1, A method for manufacturing a metal nanostructure catalyst, characterized by further including a step of performing heat treatment on the nanostructure between the step of forming the nanostructure and the step of forming the groove.

13. In the step of performing the heat treatment according to claim 12, A method for transferring a metal nanostructure catalyst, characterized in that the above heat treatment is performed at a temperature range of 500°C to 700°C for 5 minutes to 2 hours.

14. A step of forming a nanostructure in which a plurality of metal nanowires containing metal are aligned on a substrate; A step of forming a protective layer containing an organic material on the above nanostructure; A step of forming a groove adjacent to the nanostructure on one surface of the substrate on which the nanostructure is formed; A step of separating the nanostructure from the substrate by applying an etching solution onto one surface of the substrate to fill the groove; and A method for transferring a metal nanostructure catalyst comprising a metal, comprising the step of attaching the separated nanostructure to a transfer target substrate.

15. In claim 14, the step of attaching the nanostructure to the transfer target substrate is, A step of introducing the above nanostructure into a deionized water (DI water) solution; A step of introducing the transfer target substrate into the deionized water solution so that the transfer target substrate comes into contact with the nanostructure from below the nanostructure; and A method for transferring a metal nanostructure catalyst, characterized by including the step of drying the nanostructure and the transfer target substrate.

16. In claim 15, the step of attaching the nanostructure to the transfer target substrate is, A method for transferring a metal nanostructure catalyst, characterized by further including the step of surface treating the transfer target substrate so that hydroxyl groups are formed on the surface of the transfer target substrate before immersing the transfer target substrate in the deionized water solution.

17. In Paragraph 14, The above nanostructure contains copper (Cu), and The above substrate is a silicon wafer (Si wafer) substrate, and A method for transferring a metal nanostructure catalyst, characterized in that the etching solution is an aqueous potassium hydroxide (KOH) solution.

18. In Paragraph 14, The above substrate is a silicon oxide wafer (SiO₂ x wafer) is a substrate, and A method for transferring a metal nanostructure catalyst, characterized in that the above etching solution is a buffered oxide etchant (BOE).

19. In the step of forming the groove adjacent to the nanostructure according to claim 14, A method for transferring a metal nanostructure catalyst containing metal, characterized in that the groove is formed to completely surround the boundary of the protective layer on a flat surface.

20. A first metal nanowire layer comprising a plurality of metal nanowires spaced apart from each other in a plane and containing copper (Cu); and It comprises a second metal nanowire layer containing gold (Au) and including a plurality of metal nanowires spaced apart from each other in a planar manner, and A metal nanostructure catalyst in which a plurality of the first metal nanowire layer and the second metal nanowire layer are alternately stacked.

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