JP2016167386A - Composite material of ferromagnetic metal nanostructure and two-dimensional structure substrate, manufacturing method thereof, and electrode material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nanowire composite material having sufficiently high mechanical strength such as tensile strength in a thin film direction and excellent in handling, reliability and life. A ferromagnetic metal nanostructure including a base material, a ferromagnetic metal plating layer on the base material, and a ferromagnetic metal nanowire formed from the plating layer in a direction substantially perpendicular to the plating layer. A composite material including a body. It is preferable that the ferromagnetic metal nanowires be formed in a hair-covered state in which hairs are evenly arranged by forming the ferromagnetic metal nanowires close to each other. [Selection diagram] Fig. 3

Description

  The present invention relates to a novel composite material of a ferromagnetic metal nanostructure and a two-dimensional structure substrate, a novel production method of the composite material, and a novel electrode material using the composite material.

  Metal nanostructures such as metal nanoparticles and metal nanowires exhibit different physical properties from bulk metal materials, such as having high catalytic activity depending on the type of metal constituting the metal nanostructure. Therefore, the metal nanostructure is expected to be used in various industrial fields as a material such as an electronic component, an optical component, and a magnetic material.

  Here, as a method for producing metal nanorods and metal nanowires including metal nanotubes, for example, metal electrodeposition is carried out in the pores of a template such as a porous film having fine pores, and rod-like or tube-like metal A method of growing nanostructures is exemplified (template method).

  As another simpler method for producing metal nanowires, Patent Document 1 describes a method of forming a ferromagnetic metal into a nanowire in a magnetic field. Utilization as a material for battery electrodes has also been proposed. This metal nanowire has a three-dimensional structure in which the wires are entangled with each other in the form of a nonwoven fabric. By forming an electrode active material layer on the metal nanowire, an electrode that realizes high capacity, high cycle characteristics, and high rate characteristics can be obtained. It shows that it is obtained.

JP 2011-58021 A

  However, the non-woven metal nanowires obtained by the above-mentioned conventional technology have a large specific surface area exhibited by nanomaterials such as nanoparticles and nanowires, and also have metal foil-like properties, and are easy to handle. On the other hand, it has the disadvantage that it is soft when molded into a sheet and has insufficient mechanical strength, particularly tensile strength in the two-dimensional film direction. Therefore, the metal nanowire sheet is extremely difficult to continuously produce in a roll-to-roll manner, has low reliability, and has a problem in life.

  In order to overcome this problem, the present invention combines a substrate such as a metal foil or a polymer film with metal nanowires, and the tensile strength in the two-dimensional direction of the sheet (the direction parallel to the surface of the substrate). Therefore, it is intended to provide a composite material having a sufficiently high mechanical strength and excellent in handling, reliability, and life.

  The present invention combines a substrate (metal foil, polymer thin film, etc.) and a metal nanowire using a simple manufacturing method by a liquid phase reduction method in a magnetic field, and the mechanical strength of the substrate itself and Provided is a nanocomposite material having both physical properties and characteristics resulting from a high specific surface area that is a feature of nanostructures. And the possibility of using it as a secondary battery electrode material is provided.

  That is, the present invention relates to a ferromagnetic metal comprising a base material, a ferromagnetic metal plating layer on the base material, and ferromagnetic metal nanowires formed substantially perpendicular to the plating layer from the plating layer. A composite comprising a nanostructure is provided.

  A step of placing the substrate in contact with a solution containing ferromagnetic metal ions and a reducing agent; a step of applying a magnetic field in the thickness direction of the substrate to the substrate; As a result, forming the ferromagnetic metal plating layer on the base material, and forming a ferromagnetic metal nanowire in the same direction as the lines of magnetic force on the ferromagnetic metal plating layer. I will provide a.

  According to the composite material of the ferromagnetic metal nanostructure and the two-dimensional structure base material that is one aspect of the present invention, the nanostructure densely oriented in the direction perpendicular to the base material surface on the two-dimensional structure base material In addition, the specific surface area of the entire composite can be significantly increased, and at the same time, there is no physical partition between the external space and the nanostructure, so that there is no gap between the external space and the nanostructure. The movement of the substance becomes easy. In terms of the movement of substances, this movement can be made easier by using a two-dimensional structure base material having a mesh shape or a base material having a large number of through holes. In addition, since this composite material has a structure in which the nanostructure and the two-dimensional structure base material are vertically oriented, the composite material can be maintained while maintaining the shape and flexibility of the nanostructure part by selecting the two-dimensional structure base material. It is possible to achieve both the overall strength and flexibility. Moreover, when this composite material is used for a battery electrode, heat and electron transfer can be promoted by selecting a two-dimensional structure base material having high thermal and electrical conductivity.

1 is a conceptual diagram of a method for manufacturing a composite material of Example 1. FIG. FIG. 2 is an external view photograph of the composite material obtained in Example 1. FIG. 3 is an SEM photograph (cross section) of the composite material obtained in Example 1. 4 is a SEM photograph (surface) of the composite material obtained in Example 1. FIG. FIG. 5 is a conceptual diagram of a method for manufacturing the composite material of Comparative Example 1. FIG. 6 is an appearance photograph of the composite material obtained in Comparative Example 1. FIG. 7 is an SEM photograph (cross section) of the composite material obtained in Comparative Example 1.

[Structure of composite material]
In the present specification, the composite material means a composite material in which two or more materials are combined. In the present invention, a composite material in which a base material and a ferromagnetic metal nanostructure are combined is referred to. means.

  The base material which is a constituent element of the composite material of the present invention is a material having a sheet-like shape (or a foil-like shape) with a small thickness. The thickness is usually 10 μm to 1 mm, but a base material having such a strength that it cannot be broken by a roll-to-roll manufacturing method is preferable.

  Various materials can be used for the substrate. For example, a metal material, a metal oxide material, ceramics, an organic material, a polymer material, a sheet made of paper, a nonwoven fabric sheet, and the like can be given. In this, a metal material is preferable from a viewpoint of electrical conductivity and strength. In addition, the base material without a hole may be sufficient as a base material, and a porous body may be sufficient as it.

  Specific examples of the metal material include aluminum, silicon, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, gallium, germanium, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, Examples thereof include cadmium, indium, tin, hafnium, tantalum, tungsten, osmium, iridium, platinum, gold, and metal alloys arbitrarily selected from these.

  Examples of the metal oxide material include oxides and composite oxides of the above metals, such as aluminum oxide, iron oxide, titanium oxide, manganese oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, bismuth oxide, chromium oxide, Examples thereof include nickel oxide, copper oxide, hafnium oxide, tungsten oxide, zinc molybdate, molybdenum trioxide, zinc stannate, and tin oxide.

  As the organic material, semiconductor organic materials such as Alq3, NPD, CuPc, and pentacene can also be used.

  Polymer materials include polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyether ether ketone, polyether ketone, polysulfone, polyether sulfone, polyphenylene sulfide, polyarylate, poly Aromatic hydrocarbon polymers composed of one or two or more copolymers or mixtures of ether imide, polystyrene, polyimide and the like can be mentioned.

  Non-limiting examples of olefin polymer films include one or more copolymers or mixtures of low density or high density polyethylene, ultrahigh molecular weight polyethylene, polypropylene, polybutene, polymethylpentene, and the like. The film comprised from these is mentioned.

  Non-limiting examples of the fluorine polymer film include polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer, tetrafluoroethylene-hexafluoropropylene copolymer, polytetrafluoroethylene, tetrafluoroethylene-perfluoroethylene film. Examples include films composed of fluoroalkyl vinyl ether copolymers, polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene-vinylidene fluoride copolymers, and mixtures thereof.

  In addition, polycarbonate, phenol resin, melamine resin, (meth) acrylate resin, unsaturated polyester resin, epoxy resin, polyurethane resin, and the like can also be used.

  In addition, the surface state of the base material of the present invention is not particularly limited. Even if the surface of the substrate is not completely smooth, the composite material of the present invention can be formed.

  Next, the ferromagnetic metal nanostructure will be described. The ferromagnetic metal nanostructure includes a ferromagnetic metal plated layer and ferromagnetic metal nanowires formed in a direction substantially perpendicular to the plated layer from the plated layer.

  The ferromagnetic metal plating layer is disposed so as to contact the surface of the substrate. The thickness of the ferromagnetic metal plating layer is about 10 μm to 100 μm, but is not particularly limited and can be changed depending on the application.

  Although the ferromagnetic metal plating layer may be in a state of covering only a part of the base material, it is preferable that the ferromagnetic metal plating layer is covered over the entire base material because of excellent material performance. According to the present invention, since the ferromagnetic metal plating layer is bonded to the base material with sufficient strength, the strength as a composite material is also high.

  The component of the ferromagnetic metal plating layer is not particularly limited as long as it is a metal or metal alloy having magnetism. The component is preferably a metal including nickel, cobalt, iron, and at least two metal alloys arbitrarily selected from them. The ferromagnetic metal plating layer can contain other metals other than the ferromagnetic metal. Of the components of the ferromagnetic metal plating layer, the content of other metal components is preferably 30% or less, more preferably 10% or less, and even more preferably 5% or less. Good.

  Next, the ferromagnetic metal nanowire will be described.

  The ferromagnetic metal nanowire is a ferromagnetic metal having a fiber shape protruding from the ferromagnetic metal plating layer. As used herein, the term “wire” includes meanings such as rods and fibers. In addition, when calling it a nanowire, the diameter or length shall point out the wire which is a nano scale.

  The shape of the cross section of the ferromagnetic metal nanowire is not particularly limited, and is usually a circle or an ellipse. The diameter (in the case of an ellipse, the major axis) is usually 10 nm to 300 nm, preferably 50 nm to 200 nm. The length of the ferromagnetic metal nanowire is usually 10 μm to 800 μm, preferably 200 μm to 500 μm. The cross section of the ferromagnetic metal nanowire can be made substantially the same area from the boundary portion with the ferromagnetic metal plating layer to the vicinity of the tip.

  A plurality of ferromagnetic metal nanowires protrude from the ferromagnetic metal plating layer and exist over a part or the whole of the ferromagnetic metal plating layer.

The density of the ferromagnetic metal nanowires is 50,000 to 100,000 per 1 mm ^{2 of the} ferromagnetic metal plating layer, but the higher the density possible, the higher the conductivity and the higher specific surface area of the composite material can be obtained. Preferred (for example, the state as shown in FIG. 3).

  The shape of the ferromagnetic metal nanowire is formed in a direction perpendicular to the ferromagnetic metal plated layer from the ferromagnetic metal plated layer. However, when the length of the ferromagnetic metal nanowire is long, the ferromagnetic metal nanowire is caused by its own weight. The wire may tilt.

  The ferromagnetic metal nanowires are preferably in a state where the ferromagnetic metal nanowires are generated from the base material, are densely packed toward the tip, and are aligned in one direction like fur hair. Thereby, a composite material can have high electroconductivity and a high specific surface area, maintaining the three-dimensional structure formed with a mutual nanowire. In the present specification, the state aligned in one direction in this way (for example, the state as shown in FIG. 3) is referred to as a coat.

  The component of the ferromagnetic metal nanowire is not particularly limited as long as it is a metal or metal alloy having magnetism like the ferromagnetic metal plating layer. The component is preferably a metal including nickel, cobalt, iron, and at least two metal alloys arbitrarily selected from them. The ferromagnetic metal plating layer can contain other metals other than the ferromagnetic metal. Of the components of the ferromagnetic metal plating layer, the content of other metal components is preferably 30% or less, more preferably 10% or less, and even more preferably 5% or less, and does not contain any other metal components. It can also be.

  The ferromagnetic metal plating layer and the ferromagnetic metal nanowire may be the same component or different components, but are preferably the same component from the viewpoint of ease of production and conductivity.

  The composite material of the present invention described above has a high specific surface area and a high tensile strength in a direction parallel to the surface of the substrate. Such a composite material has high productivity and is expected to be used as an electrode material for a secondary battery.

[Production method of composite material]
Next, the manufacturing method of the composite material of this invention is demonstrated.

  The production method of the present invention employs a method of reducing ferromagnetic metal ions and precipitating them on a substrate.

[Arrangement of magnet and substrate]
The base material is placed in a reaction vessel for depositing the ferromagnetic metal on the base material, and a magnet is arranged so that a magnetic field can be applied in the thickness direction of the base material. Even when the magnetic field is applied in a direction perpendicular to the thickness direction of the base material (a direction parallel to the surface of the base material), the ferromagnetic metal plating layer and the ferromagnetic metal nanowire do not grow uniformly on the base material. However, it is not preferable because the wire cannot be grown at all.

  As the type of magnet, a plate magnet, electromagnetic, superconducting magnet or the like can be used, and the magnetic force is 1 mT to 500 mT, preferably 10 mT to 300 mT.

  When the thickness direction of the substrate is arranged in the vertical direction in the reaction tank, the magnets are installed above and below the reaction tank. The position of the magnet may be arranged so as to be in contact with the reaction vessel, or may be arranged in a state where a certain distance is separated.

  Moreover, in order to adjust a magnetic flux density, a bar magnet etc. other than the said magnet can also be arrange | positioned in a reaction tank.

[Preparation of ion-containing solution of ferromagnetic metal]
Next, an ion-containing aqueous solution of a ferromagnetic metal is prepared. The solution containing ferromagnetic metal ions usually has a concentration of about 0.001 to 1 mol / l. When the concentration is within the above range, the length of the wire to be formed is substantially uniform, so that the predetermined characteristics can be exhibited in any part of the composite material.

  Ferromagnetic metal ions can be used as the raw material of the ferromagnetic metal ions, and examples thereof include metal acetates, metal chlorides, metal sulfates, and metal nitrates. For example, these salts may be hydrates or anhydrides. Examples of the metal salt of the ferromagnetic metal include cobalt acetate (II) tetrahydrate, cobalt acetate (II) anhydride, cobalt sulfate (II) heptahydrate, cobalt sulfate (II) anhydride, cobalt chloride ( II) hexahydrate, cobalt chloride (II) anhydride, cobalt nitrate (II) hexahydrate, cobalt nitrate (II) anhydride, nickel acetate (II) tetrahydrate, nickel acetate (II) anhydride , Nickel chloride (II) hexahydrate, nickel chloride (II) anhydride, nickel sulfate (II) hexahydrate, nickel sulfate (II) anhydride, nickel nitrate (II) hexahydrate, nickel nitrate ( II) Anhydride, iron (II) sulfate heptahydrate, iron (II) sulfate anhydride and the like.

  The solvent of the ferromagnetic metal ion-containing solution is preferably water from the viewpoint of ease of handling, but an organic solvent can also be used.

  The organic solvent is not particularly limited, and examples thereof include alcohols having 1 to 6 carbon atoms, alkylene glycols having 2 to 4 carbon atoms, ketones having 3 to 6 carbon atoms, and alkylene glycol alkyl ethers having 3 to 6 carbon atoms. Can be mentioned.

  Examples of the alcohol include methanol, ethanol, isopropyl alcohol, propyl alcohol, butanol, pentanol, and hexanol. Examples of the alkylene glycol include ethylene glycol and propylene glycol. Examples of the alkylene glycol alkyl ether include ethylene glycol methyl ether, ethylene glycol mono-n-propyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether, and propylene glycol propyl ether. Examples of the ketone include acetone, methyl ethyl ketone, ethyl isobutyl ketone, and methyl isobutyl ketone.

  Among these organic solvents, propylene glycol is preferable from the viewpoint of availability and excellent dispersibility of metal particles in the liquid phase.

  According to the production method of the present invention, a nanoparticle nucleus composed of a ferromagnetic metal formed by reducing and precipitating a ferromagnetic metal ion is formed to generate a ferromagnetic metal nanostructure. From the viewpoint of more efficiently performing this generation, it is preferable to add a nucleating agent for forming the ferromagnetic metal nanoparticle nuclei to the ferromagnetic metal ion-containing solution. From the viewpoint of promoting the reduction reaction at room temperature, the nucleating agent preferably contains a metal having a catalytic action for promoting the reduction.

Examples of the nucleating agent is not particularly limited, for example, chloroplatinic acid hexahydrate _{(H 2 [PtCl 6] ·} 6H 2 O), lead chloride, silver nitrate and the like. Of these, chloroplatinic acid hexahydrate is preferred from the viewpoint of favorably proceeding the reduction reaction. From the viewpoint of satisfactorily forming nanoparticle nuclei, for example, the nucleating agent is preferably selected from those having a metal having a smaller ionization tendency than a ferromagnetic metal.

[Addition of reducing agent or preparation of reducing solution]
In order to reduce the ferromagnetic metal ions and deposit them on the substrate, a reducing agent is added to the ferromagnetic metal ion-containing solution. When adding the reducing agent, it is preferable to prepare a reducing solution containing the reducing agent separately from the ferromagnetic metal-containing solution and add it to the ferromagnetic metal ion-containing solution from the viewpoint of easy operation.

  Examples of the reducing agent include hydrazines, hypophosphorous acid, borohydride and salts thereof, dimethylamine borane (DMAB), and the like. From the viewpoints of maintaining the ferromagnetic properties of the metal, sufficiently exhibiting the effect of applying a strong magnetic field, and obtaining a highly pure ferromagnetic metal nanostructure, hydrazines are preferred.

  The concentration of the reducing agent in the solution is preferably about 10 times the concentration of ferromagnetic metal ions in the solution from the viewpoint of good reduction reaction.

  The pH of the solution can be adjusted by adding a pH adjuster to the solvent. Such pH is preferably 10 to 13 from the viewpoint of favorably proceeding the reduction reaction.

  Examples of the pH adjuster include sodium hydroxide and potassium hydroxide. The concentration of the pH adjusting agent in the liquid phase is preferably 0.1 mol / l to 1 mol / l from the viewpoint of obtaining a metal nanostructure having an appropriate size.

  In addition, a dispersing agent or an additive can be appropriately added to the ferromagnetic metal ion-containing solution or the reducing solution.

[reaction]
Next, while applying a magnetic field in the arranged reaction vessel, the prepared ferromagnetic metal ion-containing solution and a reducing agent (in some cases, a reducing solution) are mixed and reacted. The reaction is preferably performed at a temperature higher than room temperature in order to increase the reaction rate, for example, 40 to 100 ° C, more preferably 50 to 90 ° C.

  The reaction is carried out for about 1 hour. After completion of the reaction, the substrate is taken out and washed with ion exchange water and ethanol.

  By performing such a reaction, a ferromagnetic metal plating layer and a ferromagnetic metal nanowire protruding perpendicularly from the plating layer are formed over a part or the whole of the substrate. Ferromagnetic metal nanowires can cause self-organization such as alignment along the magnetic field direction by the action of a magnetic field. Thereby, a nanostructure can be formed.

  The resulting composite material has a ferromagnetic metal with an infinite number of wires growing perpendicular to the substrate and having a very high specific surface area. By utilizing this high specific surface area, it is expected that the composite material of the present invention is used as a material for an electrode of a fuel cell.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, these Examples are only the illustrations for demonstrating this invention suitably, and do not limit this invention at all.

  In Examples and Comparative Examples, confirmation was made using SEM images in order to confirm the state of the wires. SEM used was FE-SEM (SM-Z11040TTV) manufactured by JEOL.

[Example 1]
A reaction vessel is installed on a plate magnet having a magnetic flux density of about 30 mT magnetized in the thickness direction, and a two-dimensional structure base is formed on the bottom surface of the reaction vessel so that a magnetic field perpendicular to the substrate surface is applied. A copper foil base material having a thickness of 30 μm was installed (FIG. 1). Subsequently, Ni (II) chloride hexahydrate (1.9008 g), 3Na citrate dihydrate (0.8821 g), and H ₂ [PtCl ₆ ] .6H ₂ O (0.0540M) in the reaction vessel. ) Mixed aqueous solution (80 g) adjusted to 80 ° C. with caustic soda containing aqueous solution (0.2956 g) and aqueous solution adjusted to 80 ° C. with caustic soda containing hydrazine monohydrate (4 g) (84 g) was mixed and reacted at 80 ° C. for 1 hour, and a composite metal containing copper foil, Ni plating layer formed on the copper foil, and Ni nanowires formed vertically from the Ni plating layer A nanostructured composite foil was obtained. The composite foil was subsequently washed with ion exchanged water and ethanol, and the solvent was removed by drying.

  The appearance photograph (FIG. 2) and SEM images (FIGS. 3 and 4) of the obtained metal nanostructure composite foil are shown below. It was observed that the copper foil and the Ni nanowire were bonded via the Ni plating layer. Moreover, it was confirmed that Ni nanowires are densely packed and hairs are in a hair-like shape in which the hairs are aligned in one direction.

[Comparative Example 1]
A reaction vessel is installed between two opposing plate magnets having a magnetic flux density of about 200 mT magnetized in the thickness direction, and a magnetic field in a direction substantially parallel to the substrate surface is applied. A copper foil base material having a thickness of 30 μm, which is a two-dimensional structure base material, was placed on the upper surface (FIG. 5). Subsequently, in the same reaction vessel as in Example 1, Ni (II) chloride hexahydrate (1.9001 g), 3Na citrate dihydrate (0.8817 g), and H ₂ [PtCl ₆ ] · 6H A mixed aqueous solution (80 g) adjusted to 80 ° C. at pH 12.5 with caustic soda containing ₂ O (0.0540 M) aqueous solution (0.2948 g) and caustic soda containing hydrazine monohydrate (4 g) at pH 12.5 An aqueous solution (84 g) adjusted to 80 ° C. is mixed and reacted at 80 ° C. for 1 hour to obtain a composite of the above-mentioned installation copper foil whose surface is Ni-plated and a non-woven Ni nanowire covering the periphery. It was. The composite was subsequently washed with ion exchanged water and ethanol, and the solvent was removed by drying.

  An appearance photograph (FIG. 6) and an SEM image (FIG. 7) of the obtained composite are shown below. A part of the nonwoven fabric Ni was formed on the copper foil. The bond between the layer and the Ni nanowire could not be confirmed.

Although the tensile strength (test based on JIS Z2240) of the surface direction of the composite foil of Example 1 was confirmed, the composite material of Example 1 was compared with the conventional nanowire only in which the material was 5 N / mm ² or less. Has also been confirmed to have a very high strength of about 350 N / mm ² .

[effect]
The effects of each configuration are listed below.
[1] A ferromagnetic metal nanostructure comprising a base material, a ferromagnetic metal plating layer on the base material, and a ferromagnetic metal nanowire formed in a direction substantially perpendicular to the plating layer from the plating layer The composite material containing, has a high specific surface area as compared with a conventional metal nanowire sheet, has a high tensile strength, and can be expected to form a sheet by a roll-to-roll method. Further, since the ferromagnetic metal plating layer is fused with the base material with sufficient strength, there is little risk of the composite material being decomposed.
[2] When the ferromagnetic metal nanowires are densely packed and the hairs are in a hair-like shape arranged in one direction, the three-dimensional structure formed by the nanowires is maintained and high. The composite material has electrical conductivity and a high specific surface area.
[3] When the ferromagnetic metal plating layer and the ferromagnetic metal nanowire are the same component, the manufacture of the composite material is facilitated, and the connection between the ferromagnetic metal plating layer and the ferromagnetic metal nanowire is facilitated. Is strong.
[4] When the ferromagnetic metal nanowire is at least one selected from the group consisting of nickel, cobalt, iron, and alloys thereof, it is extremely effective as an electrode material.
[5] If the substrate is a metal, it has high conductivity and is useful as an electrode material.
[6] If the base material is a copper foil, it has high conductivity, is extremely suitable as an electrode material, and also has high tensile strength, so that productivity is high and handling is easy.
[7] A secondary battery using the composite material as an electrode material is a secondary battery with cost merit because the composite material can be manufactured with high productivity.
[8] A step of disposing a base material so as to come into contact with a solution containing ions of a ferromagnetic metal and a reducing agent, a step of applying a magnetic field in the thickness direction of the base material to the base material, and applying a magnetic field As a result, forming a ferromagnetic metal plating layer on the substrate and forming a ferromagnetic metal nanowire on the ferromagnetic metal plating layer in the same direction as the lines of magnetic force. If it exists, the composite material of this invention can be manufactured easily, and the said composite material has high tensile strength. According to the production method of the present invention, the ferromagnetic metal plating layer and the ferromagnetic metal nanowire can be uniformly formed on the substrate.
[9] If the reducing agent is hydrazines, the reduction reaction proceeds easily and the deposition rate of the ferromagnetic metal is fast.
[10] In this method, when the ferromagnetic metal ions are ions of at least one metal selected from the group consisting of nickel, cobalt, and iron, all of them are strong magnetic metals. Can easily produce metal nanowires.
[11] In the above method, when the base material is a copper foil, the base material is a stable base material, so that it is easy to handle and has high conductivity and is extremely suitable as an electrode material.

  The composite material of the present invention utilizes the above properties, and as an electrode material, further, a catalyst, a battery cell, a filter, a film material, an absorbent / adsorbent, a nanocomposite material, a transparent conductive film material, and an adhesive filler , Conductive paste, printable electronics materials, electronic components, wiring materials, MEMS component materials, sensor materials, coating materials, bio / medical device materials, heat dissipation / heat exchange materials, photo / electric / magnetic response materials, antireflection materials, emitters It can also be used for magnetism imparting materials, magnetic sheets, sound absorbing materials, hydrogen storage materials, electronic device materials, and electromagnetic wave shielding materials.

Claims (11)

A ferromagnetic metal nanostructure comprising a base material, and a ferromagnetic metal plating layer on the base material, and a ferromagnetic metal nanowire formed in a direction substantially perpendicular to the plating layer from the plating layer. Composite material.   The composite material according to claim 1, wherein the ferromagnetic metal nanowires are formed so as to be densely packed with each other, whereby the ferromagnetic metal nanostructure has a hair-like shape in which hairs are aligned.   The composite material according to claim 1, wherein the ferromagnetic metal plating layer and the ferromagnetic metal nanowire are the same component.   The composite material according to any one of claims 1 to 3, wherein the ferromagnetic metal nanowire is at least one selected from the group consisting of nickel, cobalt, iron, and alloys thereof.   The composite material according to claim 1, wherein the base material is a metal.   The composite material according to claim 1, wherein the base material is a copper foil.   The secondary battery which uses the composite material as described in any one of Claims 1 thru | or 6 as an electrode material. Placing the substrate in contact with a solution containing ferromagnetic metal ions and a reducing agent;
Applying a magnetic field in the thickness direction of the base material to the base material;
Forming a ferromagnetic metal plating layer on the substrate as a result of applying a magnetic field, and forming a ferromagnetic metal nanowire from the ferromagnetic metal plating layer in the same direction as the lines of magnetic force. Method.   The method according to claim 8, wherein the reducing agent is hydrazines.   The method according to claim 8 or 9, wherein the ferromagnetic metal ions are ions of at least one metal selected from the group consisting of nickel, cobalt, and iron. The method according to claim 8, wherein the substrate is a copper foil.