WO2011115214A1 - Nanoparticule de nickel-cobalt et procédé de fabrication associé - Google Patents

Nanoparticule de nickel-cobalt et procédé de fabrication associé Download PDF

Info

Publication number
WO2011115214A1
WO2011115214A1 PCT/JP2011/056408 JP2011056408W WO2011115214A1 WO 2011115214 A1 WO2011115214 A1 WO 2011115214A1 JP 2011056408 W JP2011056408 W JP 2011056408W WO 2011115214 A1 WO2011115214 A1 WO 2011115214A1
Authority
WO
WIPO (PCT)
Prior art keywords
nickel
cobalt
nanoparticles
heating
salt
Prior art date
Application number
PCT/JP2011/056408
Other languages
English (en)
Japanese (ja)
Inventor
智央 山内
雄二 和田
保徳 塚原
勝弘 山田
修治 井上
英朗 野本
亮次 川端
Original Assignee
新日鐵化学株式会社
国立大学法人大阪大学
岩谷産業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 新日鐵化学株式会社, 国立大学法人大阪大学, 岩谷産業株式会社 filed Critical 新日鐵化学株式会社
Priority to CN201180014315.6A priority Critical patent/CN102811829B/zh
Priority to JP2012505745A priority patent/JP5830010B2/ja
Priority to KR1020127021767A priority patent/KR101671049B1/ko
Publication of WO2011115214A1 publication Critical patent/WO2011115214A1/fr

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • B22F1/17—Metallic particles coated with metal
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F9/00—Making metallic powder or suspensions thereof
    • B22F9/16—Making metallic powder or suspensions thereof using chemical processes
    • B22F9/18—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds
    • B22F9/24—Making metallic powder or suspensions thereof using chemical processes with reduction of metal compounds starting from liquid metal compounds, e.g. solutions
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2999/00—Aspects linked to processes or compositions used in powder metallurgy

Definitions

  • the present invention relates to nanoparticles having a core-shell structure made of different metals.
  • Cobalt nanoparticles are cheaper than silver nanoparticles, chemically more stable than copper nanoparticles, and have higher catalytic activity and saturation magnetization than nickel particles, so various catalysts, magnetic materials, fuel cells and multilayer ceramics It is expected to be used for electrodes in capacitors.
  • cobalt is a rare metal and is considerably more expensive than nickel particles, development of cobalt particles that can extract cobalt performance in a smaller amount and a method for producing the same is desired. In order to bring out the performance of cobalt well, its particle size and particle shape must be controlled to be uniform.
  • the method for producing metal nanoparticles is roughly classified into a physical method and a chemical method.
  • the physical method is a method of pulverizing bulk metal to produce nanoparticles (pulverization method)
  • the chemical method is a method of generating metal atoms and controlling their aggregation (aggregation method).
  • pulverization method there is a limit to reducing the particle size, and the shape of the particles varies and it is difficult to make a uniform one. For this reason, the chemical method is more advantageous for controlling the shape and particle size of the particles.
  • the manufacturing method of metal nanoparticles by chemical method is classified into wet method and dry method.
  • Known chemical dry methods include CVD (chemical vapor deposition), gas evaporation, laser, sputtering, and metal droplet spraying, and the generated particles are treated at high temperature. It is spherical and has good crystallinity, but has the disadvantages of wide particle size distribution and low productivity.
  • the wet method represented by the chemical reduction method has the advantage of higher productivity and easier particle size control than the dry method. Therefore, many studies have been made with the recent development of nanotechnology. Yes.
  • a metal including a copper core and a thin film layer of a metal such as silver, palladium, platinum, or gold surrounding the copper core and having a reduction potential higher than that of copper Nanoparticles are disclosed (Patent Document 1).
  • This method for producing metal nanoparticles comprises a copper precursor comprising a copper complex such as copper nitrate, copper chloride, copper formate using tert-butylhydroxytoluene, ascorbic acid, flavonoid, etc. as a reducing agent in a solution containing a primary amine.
  • the resulting metal nanoparticles having a core-shell structure have copper particles as a core and are coated with a noble metal, so that the copper content can be increased while preventing copper oxidation.
  • the thin film layer contains a metal such as silver having an electrical conductivity superior to that of copper, it has an advantage that a wiring having an electrical conductivity superior to that of copper can be formed.
  • a metal precursor containing a first metal (for example, cobalt) that is a nanoparticle and a second metal (for example, platinum) having a reduction potential higher than that of the first metal is dissolved in an appropriate organic solvent.
  • a method for producing core-shell structured metal nanoparticles by mixing each solution and performing a metal substitution reaction between the first metal and the second metal is disclosed (Patent Document 2).
  • Patent Documents 1 and 2 realize metal nanoparticles having a core made of a metal having a low reduction potential and a shell made of a metal having a high reduction potential by different methods. However, it is not clear whether or not the core-shell structure metal nanoparticles made of other different metals can be appropriately obtained by using the manufacturing methods of Patent Documents 1 and 2. In particular, it is difficult to apply the same technique as in Patent Documents 1 and 2 to dissimilar metals having similar oxidation-reduction potentials, such as nickel and cobalt.
  • Non-patent Documents 1 and 2 the present inventors examined and reported on a Cu—Ni alloy having copper as a core and nickel having a lower reduction potential than copper in the shell (Non-patent Documents 1 and 2).
  • the Cu—Ni alloy was prepared by mixing copper formate and nickel formate separately with oleylamine, and the copper formate mixture at room temperature.
  • the nickel formate mixed solution is complexed by heating at 393 K to prepare a precursor, mixed with 1-octal, and then rapidly heated with microwaves to obtain nanoparticles.
  • JP 2007-224420 A Japanese Patent Laid-Open No. 2003-055703
  • An object of the present invention is to provide nickel-cobalt nanoparticles that can be suitably used for applications such as catalysts, magnetic materials, electrodes, etc., in which nickel forms a core and cobalt forms a shell layer, and a method for producing the same. .
  • the nickel-cobalt nanoparticles according to the present invention include a core made of nickel and a shell made of cobalt substantially covering the entire surface of the core.
  • the nickel-cobalt nanoparticles according to the present invention preferably have a nickel content in the range of 30 to 90% by mass, a cobalt content in the range of 10 to 70% by mass, and an average particle size.
  • the thickness is in the range of 10 to 200 nm, and the thickness of the shell is in the range of 1 to 50 nm.
  • the method for producing nickel-cobalt nanoparticles according to the present invention includes a step of heating a mixture containing a nickel salt, a cobalt salt and a primary amine to obtain a complexing reaction solution, and heating the complexing reaction solution. Obtaining a nickel-cobalt nanoparticle slurry.
  • the method for producing nickel-cobalt nanoparticles according to the present invention includes a step of heating a mixture containing nickel fine particles, a cobalt salt and a primary amine to obtain a complexing reaction solution, and heating the complexing reaction solution. Obtaining a nickel-cobalt nanoparticle slurry.
  • the method for producing nickel-cobalt nanoparticles according to the present invention includes a step of heating a mixture containing a cobalt salt and a primary amine to obtain a complexing reaction solution, and adding nickel fine particles to the complexing reaction solution. Heating to obtain a nickel-cobalt nanoparticle slurry.
  • the nickel salt and the cobalt salt are each represented by a linear carboxylic acid group having 1 to 3 carbon atoms or the following structural formula (1). It is characterized by having any one of the following groups.
  • substituents Ra to Rc are groups selected from the group consisting of methyl, ethyl, phenyl and halogen.
  • the substituents Ra to Rc may be the same or different from each other.
  • the carboxylic acid group is a formic acid group or an acetic acid group, and the group represented by the structural formula (1) is acetylacetonate.
  • the method for producing nickel-cobalt nanoparticles according to the present invention preferably uses microwaves as a heating means in the step of obtaining the nickel-cobalt nanoparticle slurry.
  • the nickel-cobalt nanoparticles according to the present invention are composed of a nickel core and a cobalt shell, they are suitable for applications such as catalysts, magnetic materials, and electrodes. Further, by adjusting the cobalt content according to these applications, the cost can be made appropriate, and the performance of cobalt can be maximized in each of the above applications.
  • the nickel-cobalt nanoparticles according to the present invention can be suitably obtained.
  • FIG. 2 is a transmission electron microscope (TEM) photo of the nickel-cobalt nanoparticles obtained in Example 1.
  • TEM transmission electron microscope
  • FIG. 2A It is a figure which shows the electron diffraction (ED: * Electron * diffraction) pattern from the TEM photograph area
  • 2 is a diagram showing a mapping image of nickel-cobalt nanoparticles obtained in Example 1 by STEM-EDS.
  • FIG. 3 is a diagram showing the results of line analysis of the nickel-cobalt nanoparticles obtained in Example 1 by STEM-EDS. It is a figure which shows the result of the SQUID magnetic susceptibility measurement of the nickel- cobalt nanoparticle of Example 1, 2 and the nickel particle of the comparative example 8, and a commercially available cobalt particle.
  • 4 is a diagram showing a mapping image of nickel-cobalt nanoparticles obtained in Example 2 by STEM-EDS.
  • FIG. 6 is a view showing a mapping image of nickel-cobalt nanoparticles obtained in Example 4 by STEM-EDS.
  • the nickel-cobalt nanoparticles according to the present embodiment are substantially a core made of nickel and substantially cobalt substantially covering the entire surface of the core. Includes a shell consisting of Here, the nanoparticles do not exclude the form in which the core contains a small amount of cobalt and the shell contains a small amount of nickel.
  • substantially nickel core means that a small amount of cobalt inevitably contained in the core is allowed, but most of it consists of nickel, and “substantially cobalt shell”. "Means that a small amount of nickel inevitably contained in the shell is allowed, but most consists of cobalt.
  • the nanoparticle shell covers the entire surface of the core.
  • the present invention is not limited to this, and does not exclude a form in which nickel is partially exposed. That is, “substantially covering the entire surface of the core” means not only a form in which the shell completely covers the core, but also a discontinuous formation of the shell within a range that does not impair the effect of the present invention (the function of the nanoparticles). While the partially exposed core is allowed, it means that most of the surface of the nickel-cobalt nanoparticles consists of a shell. Moreover, the structure which has an inner shell between the shell of cobalt and nickel may be sufficient as a nanoparticle.
  • the nanoparticles according to the present embodiment have, for example, a nickel content of 30 to 90% by mass and a cobalt content of 10 to 70% by mass.
  • the cobalt content of the nanoparticles can be appropriately set in consideration of the characteristics required for the application to be applied, cost, etc., but if it is less than 10% by mass, for example, the core is greatly exposed from the shell, and the catalyst performance and magnetic characteristics are reduced. The effect may not be sufficiently obtained. On the other hand, if it exceeds 70% by mass, the cost increases.
  • the average particle diameter of the nanoparticles is, for example, 10 to 200 nm, preferably 10 to 150 nm. If the average particle size of the nanoparticles is less than 10 nm, the agglomeration is severe and the dispersibility is deteriorated, which may make it unsuitable as a paste material such as a catalyst or an electrode. On the other hand, if the average particle diameter of the nanoparticles exceeds 200 nm, the specific surface area becomes small, and for example, high catalyst performance may not be exhibited.
  • the nanoparticles preferably have a Cv value [coefficient of variation; ratio ⁇ / d of average particle diameter (d) to standard deviation ( ⁇ )] of 0.01 ⁇ ⁇ / d ⁇ 0.5.
  • the thickness of the nanoparticle shell is, for example, 1 to 50 nm, preferably 5 to 20 nm. If the thickness of the nanoparticle shell layer is less than 1 nm, the amount of cobalt is so small that the catalytic activity and magnetic properties inherent in cobalt may not be sufficiently exhibited. On the other hand, if it exceeds 50 nm, the cost increases.
  • Nanoparticles have various shapes such as spherical, pseudo-spherical, spheroid, cubic, truncated tetrahedral, dihedral pyramidal, octahedral, icosahedral, and icosahedral.
  • a spherical shape or a pseudospherical shape is preferable, and a spherical shape is more preferable.
  • the shape of the nanoparticles can be confirmed by observing with a scanning electron microscope (SEM).
  • the nanoparticles according to the present embodiment described above can adjust the cobalt content according to the use of the catalyst, magnetic material, electrode, etc., to make the cost appropriate, and also draw out the performance of cobalt suitably. be able to.
  • a first example of a method for producing nanoparticles includes a step of heating a mixture containing a nickel salt, a cobalt salt and a primary amine to obtain a complexing reaction solution, and heating the complexing reaction solution to obtain nickel-cobalt nanoparticles. Obtaining a slurry.
  • the second example of the method for producing nanoparticles includes a step of heating a mixture containing nickel fine particles, a cobalt salt and a primary amine to obtain a complexing reaction solution, and heating the complexing reaction solution to obtain nickel-cobalt nanoparticles. Obtaining a slurry. That is, nickel fine particles are used in place of the nickel salt of the first example.
  • a third example of the method for producing nanoparticles includes a step of heating a mixture containing a cobalt salt and a primary amine to obtain a complexing reaction solution, adding nickel fine particles to the complexing reaction solution, and then heating to obtain nickel.
  • a cobalt nanoparticle slurry That is, the nickel fine particles of the second example are added not in the complexing reaction solution generation process but in the nickel-cobalt nanoparticle slurry generation process.
  • Both the second example and the third example are preferred embodiments. However, when nickel fine particles are added, it is necessary to highly disperse the nickel fine particles in the complexing reaction solution. If sufficient, the cobalt shell may not be formed uniformly. In that sense, the first example that does not require high dispersion processing is the most preferable method.
  • Step of obtaining complexing reaction solution In this step, a mixture containing nickel salt, cobalt salt and primary amine is heated (first example), or a mixture containing nickel fine particles, cobalt salt and primary amine is heated (second example), Or the complex containing nickel and / or cobalt is produced
  • the complexing reaction liquid refers to a reaction product liquid (reaction product) generated by a reaction between a nickel salt and / or a cobalt salt and a primary amine.
  • the complexing reaction solution contains, as a complex, a nickel complex and a cobalt complex in the first example, and a cobalt complex in the second example and the third example.
  • the nickel ions and / or cobalt ions of the nickel complex and / or cobalt complex are reduced, and the carboxylate ions coordinated to the ions are simultaneously decomposed, and finally zero-valent.
  • Ni and / or zero-valent Co are formed, and core-shell structured nanoparticles are formed.
  • the nickel salt and the cobalt salt are not particularly limited, but either one or both of a linear carboxylic acid group having 1 to 3 carbon atoms and a group represented by the following structural formula (1) are used. What has is preferable.
  • the group represented by the following structural formula (1) is a 1,3-diketonato group ( ⁇ -diketonato ligand).
  • the nickel salt and cobalt salt may be the same or different salts. Further, both the nickel salt and the cobalt salt may be anhydrides or hydrates.
  • substituents Ra to Rc are groups selected from the group consisting of methyl, ethyl, phenyl and halogen.
  • the substituents Ra to Rc may be the same or different from each other.
  • the nickel salt having a linear carboxylic acid group having 1 to 3 carbon atoms is nickel formate, nickel acetate, or nickel propionate, and it is particularly preferable to use nickel formate or nickel acetate.
  • the cobalt salt having a straight-chain carboxylic acid group having 1 to 3 carbon atoms is specifically cobalt formate, cobalt acetate or cobalt propionate, and it is particularly preferable to use cobalt formate or cobalt acetate.
  • These nickel carboxylate and cobalt carboxylate may be anhydrides or hydrates.
  • nickel carboxylate or cobalt carboxylate nickel chloride (cobalt chloride), nickel nitrate (cobalt nitrate), nickel sulfate (cobalt sulfate), nickel carbonate (cobalt carbonate), nickel hydroxide (cobalt hydroxide), etc.
  • inorganic salts dissociation (decomposition) is a high temperature, so that in the process of reducing the dissociated nickel ions (or nickel complexes) and cobalt ions (or cobalt complexes), This is not preferable because heating at a high temperature is required.
  • Examples of the group represented by the structural formula (1) include 2,4-pentadionato (also known as acetylacetonato), 2,4-hexadionato, 3,5-heptadionate, 1-phenyl-1,3-butanedionate, -Chlor-1,3-butanedionate and the like, among which acetylacetonate is preferably used.
  • the blending amount of the nickel salt and the cobalt salt is, for example, 30 to 90 parts by weight of nickel and 10 to 70 parts by weight of cobalt with respect to 100 parts by weight of the total amount of nickel and cobalt in the complexing reaction solution. It is preferable to use 50 to 80 parts by mass of nickel and 20 to 50 parts by mass of cobalt.
  • the compounding quantity of cobalt can be suitably set in consideration of the characteristics and cost required for the use of the nanoparticles, when it is less than 10 parts by mass with respect to the total amount of nickel and cobalt of 100 parts by mass, for example, There is a possibility that the core is greatly exposed from the shell and the effect of the catalyst performance and magnetic characteristics may not be sufficiently obtained.
  • the nickel fine particles used in the second and third examples of the nanoparticle production method are not limited in size, but for example, those having a particle size of 5 to 200 nm are preferably used.
  • the particle size is less than 5 nm, aggregation is severe and there is a possibility that it is difficult to disperse even in the liquid.
  • the particle size exceeds 200 nm, the specific surface area of the particles becomes too small, and there is a possibility that sufficient reaction is not performed.
  • the shape of the nickel fine particles is preferably, for example, spherical or pseudospherical, but most preferably spherical.
  • the addition amount of the nickel fine particles is preferably 30 to 90 parts by mass, and preferably 50 to 80 parts by mass with respect to 100 parts by mass of the total amount of nickel and cobalt in the complexing reaction solution in terms of metal. Is more preferable.
  • the primary amine can form a complex with a nickel ion or a cobalt ion, and effectively exhibits a reducing ability for the nickel complex (or nickel ion).
  • secondary amines have large steric hindrance, which may hinder good formation of nickel complexes and cobalt complexes, and tertiary amines cannot be used because they do not have the ability to reduce nickel ions and cobalt ions.
  • the primary amine is not particularly limited as long as it can form a complex with nickel ion or cobalt ion, and can be solid or liquid at room temperature.
  • room temperature means 20 ° C. ⁇ 15 ° C.
  • the primary amine that is liquid at room temperature also functions as an organic solvent when forming a nickel complex or a cobalt complex.
  • it is a primary amine solid at normal temperature, there is no particular problem as long as it is liquid by heating at 100 ° C. or higher, or can be dissolved using an organic solvent.
  • the primary amine also functions as a dispersing agent and can favorably disperse the nickel complex or cobalt complex in the reaction solution. Therefore, after the complex formation, the nickel complex or cobalt complex is heated and decomposed to obtain nanoparticles. Aggregation of particles at the time can be suppressed.
  • the primary amine may be an aromatic primary amine, but an aliphatic primary amine is preferred from the viewpoint of ease of nickel complex formation and cobalt complex formation in the reaction solution.
  • the aliphatic primary amine can control the particle size of the produced nanoparticles, for example, by adjusting the length of the carbon chain thereof, and is particularly advantageous when producing nanoparticles having an average particle size of 10 to 200 nm. It is.
  • the aliphatic primary amine is preferably selected from those having about 6 to 20 carbon atoms.
  • examples of such amines include octylamine, trioctylamine, dioctylamine, hexadecylamine, dodecylamine, tetradecylamine, stearylamine, oleylamine, myristylamine, and laurylamine.
  • oleylamine exists in a liquid state under the temperature conditions in the nanoparticle production process, and therefore can efficiently proceed with a reaction in a homogeneous solution.
  • the primary amine functions as a surface modifier during the production of the nanoparticles, secondary aggregation can be suppressed even after removal of the primary amine.
  • the primary amine is also preferable from the viewpoint of ease of processing operation in the washing step of separating the solid component of the produced nanoparticles after the reduction reaction and the solvent or the unreacted primary amine.
  • the primary amine is preferably one having a boiling point higher than the reduction temperature from the viewpoint of ease of reaction control when reducing the nickel complex or cobalt complex to obtain nanoparticles. That is, the aliphatic primary amine preferably has a boiling point of 200 ° C. or higher, and preferably has 9 or more carbon atoms.
  • the boiling point of C 9 H 21 N (nonylamine) of an aliphatic amine having 9 carbon atoms is 201 ° C.
  • the amount of the primary amine is preferably 2 mol or more, more preferably 2.5 mol or more, and more preferably 4 mol or more with respect to 1 mol of the total amount of nickel and cobalt in terms of metal.
  • the upper limit of the amount of primary amine is not particularly limited, but for example, from the viewpoint of productivity, it is preferably about 20 mol or less with respect to 1 mol of the total amount of nickel and cobalt in terms of metal.
  • a divalent nickel ion is known as a ligand-substituted active species, and the ligand of the complex to be formed may easily change in complex formation by ligand exchange depending on temperature and concentration.
  • carboxylate ions R 1 COO as shown in FIG. 1 , R 2 COO
  • R 1 COO as shown in FIG. 1
  • R 2 COO may be coordinated by either bidentate coordination (a) or monodentate coordination (b), and carboxylate ions are present in the outer sphere when the amine concentration is in large excess.
  • the structure (c) to be taken may be taken.
  • At least one of the ligands of A, B, C, D, E, and F must be coordinated with a primary amine.
  • the primary amine is excessively present in the reaction solution, and it is preferable that at least 2 mol per 1 mol of nickel ions is present, and 2.5 mol or more exist. It is more preferable that 4 mol or more is present.
  • Cobalt ions are thought to behave like nickel ions and form complexes.
  • the primary amine needs to be present in an excessive amount with respect to the cobalt ion, and is preferably present at least 2 mol, more preferably 2.5 mol or more, relative to 1 mol of nickel ion, It is desirable that 4 mol or more exists.
  • the complex formation reaction can proceed even at room temperature, it is preferable to perform heating at a temperature of 100 ° C. or higher in order to carry out the reaction reliably and more efficiently.
  • This heating is particularly advantageous when nickel carboxylate hydrate such as nickel acetate tetrahydrate or cobalt carboxylate hydrate is used as the nickel salt or cobalt salt.
  • the heating temperature is preferably a temperature exceeding 100 ° C., more preferably a temperature of 105 ° C. or more, so that the ligand substitution between the coordinated water coordinated with nickel carboxylate or cobalt carboxylate and primary amine is performed.
  • nickel acetate tetrahydrate has a complex structure in which two coordinated water, two acetate ions that are bidentate ligands, and two water molecules exist in the outer sphere at room temperature.
  • the heating at the time of complex formation is preferably performed at 105 to 175 ° C., for example. More preferably, the heating temperature is 125 to 160 ° C.
  • the heating time can be appropriately determined according to the heating temperature and the content of each raw material, but is preferably 15 minutes or more from the viewpoint of reliably completing the complex formation reaction. Although there is no upper limit on the heating time, heating for a long time is useless from the viewpoint of saving energy consumption and process time.
  • the heating method is not particularly limited, and may be heating by a heat medium such as an oil bath or heating by microwave irradiation.
  • the complex formation reaction can be confirmed by a change in the color of the solution when the solution obtained by mixing the nickel salt and / or cobalt salt and the primary amine is heated.
  • this complex formation reaction is carried out by measuring the absorption maximum wavelength of the absorption spectrum observed in the wavelength region of 300 nm to 750 nm using, for example, an ultraviolet / visible absorption spectrum measuring apparatus, and measuring the maximum absorption wavelength of the raw material (for example, nickel acetate). In tetrahydrate, the maximum absorption wavelength is 710 nm.), And this can be confirmed by observing the shift of the reaction solution with respect to.
  • the resulting reaction solution is heated by a method such as microwave irradiation, as described later, so that nickel of the nickel complex is obtained.
  • nickel carboxylate and cobalt carboxylate are hardly soluble under conditions other than using water as a solvent.
  • a solution containing nickel carboxylate or cobalt carboxylate is a homogeneous reaction solution.
  • the primary amine used in the present embodiment is liquid at the operating temperature conditions, and is considered to be liquefied by coordination with nickel ions or cobalt ions to form a uniform reaction solution. It is done.
  • an organic solvent other than the primary amine may be newly added.
  • the organic solvent may be mixed with the nickel salt or cobalt salt and the primary amine at the same time, but when the nickel salt or cobalt salt and the primary amine are first mixed and complexed, the organic solvent is added.
  • Primary amines are more preferable because they efficiently coordinate to nickel ions and cobalt ions.
  • the organic solvent that can be used is not particularly limited as long as it does not inhibit the complex formation between the primary amine and the nickel ion or cobalt ion.
  • the ether-based organic solvent having 4 to 30 carbon atoms, 7 carbon atoms, and the like.
  • a saturated or unsaturated hydrocarbon organic solvent having ⁇ 30, an alcohol organic solvent having 8 to 18 carbon atoms, or the like can be used. From the viewpoint of enabling use even under heating conditions such as by microwave irradiation, it is preferable to select an organic solvent having a boiling point of 170 ° C. or higher, more preferably in the range of 200 to 300 ° C. It is better to choose something. Specific examples of such an organic solvent include tetraethylene glycol and n-octyl ether.
  • Step of obtaining nickel-cobalt nanoparticle slurry the complexing reaction solution is heated to reduce the nickel complex and / or cobalt complex (nickel ion and / or cobalt ion) to a metal to generate nanoparticles.
  • the nickel complex and / or cobalt complex nickel ion and / or cobalt ion
  • the nickel complex is thermally decomposed at a lower temperature before the cobalt complex and reduced by the amine, and the nickel particles Is considered to be a core, and a cobalt shell is formed on the surface of the core.
  • a cobalt complex is dissociated by thermal decomposition, and Co (zero-valent) nanoparticles are formed from the Co 2+ complex.
  • the cobalt complex in the presence of excess oleylamine, is reduced from Co 2+ to Co (valent 0) at a lower temperature than usual (complex dissociates) using Ni as a catalyst.
  • the heating temperature is preferably 200 ° C. or higher, more preferably 220 ° C. or higher, from the viewpoint of efficiently performing the reduction reaction. From the viewpoint of efficiently performing the treatment, it is preferably 270 ° C. or lower, more preferably about 250 ° C. or lower.
  • a nickel complex is uniformly and sufficiently produced in the step of obtaining a complexing reaction solution, and a complexation reaction solution is obtained.
  • Ni (zero-valent) nuclei generated by reduction of nickel ions in the step of heating nickel it is necessary to simultaneously generate and grow Ni (zero-valent) nuclei generated by reduction of nickel ions in the step of heating nickel to obtain a nickel-cobalt nanoparticle slurry.
  • the heating temperature in the step of obtaining the complexing reaction liquid within the above specific range and ensuring that it is lower than the heating temperature in the step of obtaining the nickel-cobalt nanoparticle slurry, the particle size and shape Are easy to produce.
  • the heating temperature is too high in the step of obtaining a complexing reaction solution, the formation of a nickel complex and the reduction reaction to Ni (zero valence) proceed simultaneously, and the particles having a uniform particle shape in the step of obtaining a nickel-cobalt nanoparticle slurry May be difficult to generate.
  • the heating temperature in the step of obtaining the nickel-cobalt nanoparticle slurry is too low, the reduction reaction rate to Ni (zero valence) is slowed, and the generation of nuclei is reduced. It is not preferable also in terms of rate.
  • the heating source may be an oil bath or the like, but is preferably microwave.
  • the microwave penetrates into the complexing reaction liquid, and rapid heating and uniform heating are performed by internal heating.
  • the entire complexing reaction solution can be made uniform at a desired temperature, and the reduction, nucleation, and nucleation processes of nickel and cobalt particles occur simultaneously in the entire solution, resulting in a narrow particle size distribution.
  • Monodispersed particles can be easily produced in a short time.
  • the use wavelength of a microwave is not specifically limited, For example, it is 2.45 GHz.
  • the nanoparticle slurry obtained by heating the complexing reaction liquid is, for example, left and separated, and after removing the supernatant liquid, washed with an appropriate solvent and dried to obtain nanoparticles.
  • the above-mentioned organic solvent may be added to the complexing reaction solution as necessary.
  • the primary amine used in the complex formation reaction as an organic solvent as it is.
  • the solvent added as needed in the step of heating the complexing reaction solution is not particularly limited, and for example, alcohol such as octanol (octyl alcohol), nonpolar solvent, or the like can be used.
  • alcohol such as octanol (octyl alcohol), nonpolar solvent, or the like can be used.
  • oleylamine is used as the primary amine, the solvent can be omitted.
  • the method for producing nanoparticles according to the present embodiment can include an optional step in addition to the above steps.
  • an arbitrary treatment such as addition of a surface modifier can be performed.
  • the nanoparticle production method of the present embodiment employs a reduction method by heating using a microwave or the like in the step of obtaining the nickel-cobalt nanoparticle slurry, and therefore it is not necessary to use a strong reducing agent. However, it does not prevent the presence of a substance having a reducing action in the complex-forming reaction solution as long as the effects of the invention are not impaired.
  • a surface modifier for controlling the particle size of the nanoparticles for example, polymer resins such as polyvinylpyrrolidone (PVP), polyethyleneimine, polyacrylamide, myristic acid, olein A long-chain carboxylic acid such as an acid or a carboxylate can be added.
  • PVP polyvinylpyrrolidone
  • the surface modification amount of the obtained nanoparticles is large, there is a risk of adverse effects as impurities depending on the use. Therefore, the surface modification amount after washing the obtained nanoparticles is preferably as small as possible.
  • the amount of the surface modifier added is preferably in the range of 0.1 to 100 parts by mass with respect to 100 parts by mass of the total amount of nickel elements.
  • the surface modifier may be added at the stage of the mixture of nickel carboxylate and primary amine in the complexing reaction liquid forming step, or may be added to the complexing reaction liquid obtained in the complexing reaction liquid forming step.
  • the timing of addition is after the complexing reaction or after the formation of nickel nanoparticles.
  • the average particle size is 10 to 200 nm and the Cv value [coefficient of variation; ratio of average particle size (d) to standard deviation ( ⁇ ) ⁇ / It is possible to obtain nickel-cobalt nanoparticles composed of a nickel core and a cobalt shell, wherein d] has a narrow particle size distribution of 0.01 ⁇ ⁇ / d ⁇ 0.5.
  • STEM-EDS scanning transmission electron microscope
  • the analysis in the vicinity of the particle surface shows a simple concentration on the particle surface, but the analysis result in the vicinity of the center of the particle is the sum of the concentration of the metal element on the particle surface and the inside (core). Therefore, in the result of this analysis, the average value of the thickness of the layer in which the strength of cobalt is higher than that of nickel is defined as the thickness of the cobalt shell layer.
  • the composition of the obtained particles was analyzed by ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectrometry).
  • Example 1 Oleylamine (275 mmol) was added to cobalt formate dihydrate (12.5 mmol) and nickel acetate tetrahydrate (12.5 mmol), followed by heating at 120 ° C. for 20 minutes under a nitrogen flow to obtain a complexing reaction solution. Next, the complexing reaction solution was heated to 225 ° C. using a microwave, and the temperature was maintained for 30 minutes to obtain a nanoparticle slurry. The nanoparticle slurry was allowed to stand and separated, and the supernatant was removed, followed by washing with hexane three times. Then, it dried with the vacuum dryer maintained at 60 degreeC for 6 hours, and obtained the nanoparticle.
  • the TEM (Transmission Electron Microscope, transmission electron microscope) photograph of the obtained nanoparticles is shown in FIG. 2A
  • the ED (Electron Diffraction) pattern is shown in FIG. 2B.
  • Spherical uniform particles having an average particle diameter of 82 nm were formed. It can also be seen from the ED pattern that the nanoparticles are fcc-structured metals that do not contain oxides.
  • a photograph of the STEM-EDS mapping image is also shown in FIG. Since nickel is distributed in the center of the nanoparticle and cobalt is distributed on the surface of the nanoparticle, it can be seen that the nanoparticle has a Ni (core) -Co (shell) structure.
  • the thickness of the cobalt shell layer (shell) is about 13 nm.
  • the result of the saturation magnetization (unit: emu / g) obtained by SQUID magnetic susceptibility measurement is shown in FIG.
  • the saturation magnetization is lower than that of commercially available cobalt nanoparticles (particle size of 50 nm or less, manufactured by Aldrich), it can be seen that the saturation magnetization is significantly increased as compared with the nanoparticles of Comparative Example 8 described later.
  • Example 2 to 7, Comparative Examples 1 to 8 In Examples 2 to 7 and Comparative Examples 1 to 8, according to Example 1 except that the kind of nickel salt and cobalt salt and the kind of heating source and reaction temperature (heating temperature) in the step of obtaining the nanoparticle slurry were changed. Nanoparticles were prepared. The results are shown in Table 1 together with Example 1. In each example and each comparative example, the oleylamine / (Ni salt + Co salt) molar ratio is 10 in all cases. Moreover, the heating method of the complexing reaction liquid was all performed by microwave heating except Example 3 using an oil bath.
  • nickel-cobalt nanoparticles having an average particle diameter of 10 to 200 nm and a cobalt shell layer of 1 to 50 nm can be obtained by using formic acid, acetate or acetylacetone salt as nickel salt and cobalt salt. It was done. Further, from FIG. 5, it was confirmed that the nickel-cobalt nanoparticles of Examples 1 and 2 were close to the saturation magnetization of cobalt.
  • Example 8 12.5 mmol of cobalt formate dihydrate and 25 mmol of nickel particles having an average particle size of 100 nm and a Cv value of 0.14 (no cobalt salt is used and complexed from nickel acetate tetrahydrate according to the first example above)
  • a complexation reaction solution was obtained by adding 125 mmol of oleylamine to particles prepared by heating and heating it, and then heating it at 120 ° C. for 20 minutes under a nitrogen flow. Next, the complexing reaction solution was heated to 225 ° C. using a microwave, and the temperature was maintained for 30 minutes to obtain a nickel-cobalt nanoparticle slurry.
  • the nickel-cobalt nanoparticle slurry was allowed to stand and separated, and the supernatant was removed, followed by washing with hexane three times. Thereafter, it was dried for 6 hours with a vacuum dryer maintained at 60 ° C. to obtain nickel-cobalt nanoparticles.
  • the average particle diameter of the obtained nickel-cobalt nanoparticles was 120 nm, the Cv value of the particle size distribution was 0.15, and the thickness of the cobalt shell layer was 17 nm.
  • Example 9 125 mmol of oleylamine was added to 12.5 mmol of cobalt formate dihydrate and heated at 120 ° C. for 20 minutes under a nitrogen flow to obtain a complexing reaction solution. Next, 25 mmol of nickel particles having an average particle diameter of 100 nm and a Cv value of 0.14 were obtained in the complexing reaction solution (cobalt salt was not used, a complexing reaction was obtained from nickel acetate tetrahydrate, The prepared particles; Comparative Example 8) was added and stirred well, and then heated to 225 ° C. using microwaves, and the temperature was maintained for 30 minutes to obtain a nickel-cobalt nanoparticle slurry.
  • the nickel-cobalt nanoparticle slurry was allowed to stand and separated, and the supernatant was removed, followed by washing with hexane three times. Thereafter, it was dried for 6 hours with a vacuum dryer maintained at 60 ° C. to obtain nickel-cobalt nanoparticles.
  • the average particle diameter of the obtained nickel-cobalt nanoparticles was 117 nm, the Cv value of the particle size distribution was 0.15, and the thickness of the cobalt shell layer was 15 nm.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Electrochemistry (AREA)
  • Manufacture Of Metal Powder And Suspensions Thereof (AREA)
  • Powder Metallurgy (AREA)

Abstract

La présente invention concerne une nanoparticule de nickel-cobalt comprenant un noyau, qui comprend essentiellement du nickel, et une coquille, qui recouvre essentiellement l'ensemble du noyau et qui comprend essentiellement du cobalt. La présente invention concerne également un procédé de fabrication de ladite nanoparticule comprenant : une étape au cours de laquelle un mélange contenant un sel de nickel ou des nanoparticules de nickel, un sel de cobalt et une amine primaire est chauffé pour produire une solution de réaction, ou une étape au cours de laquelle un mélange contenant un sel de cobalt et une amine primaire est chauffé pour produire une solution de réaction ; et une étape au cours de laquelle la solution de réaction est chauffée pour produire une pâte de nanoparticules de nickel-cobalt.
PCT/JP2011/056408 2010-03-17 2011-03-17 Nanoparticule de nickel-cobalt et procédé de fabrication associé WO2011115214A1 (fr)

Priority Applications (3)

Application Number Priority Date Filing Date Title
CN201180014315.6A CN102811829B (zh) 2010-03-17 2011-03-17 镍-钴纳米粒子及其制造方法
JP2012505745A JP5830010B2 (ja) 2010-03-17 2011-03-17 ニッケル−コバルトナノ粒子の製造方法
KR1020127021767A KR101671049B1 (ko) 2010-03-17 2011-03-17 니켈-코발트 나노 입자 및 그 제조 방법

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2010-060773 2010-03-17
JP2010060773 2010-03-17

Publications (1)

Publication Number Publication Date
WO2011115214A1 true WO2011115214A1 (fr) 2011-09-22

Family

ID=44649297

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2011/056408 WO2011115214A1 (fr) 2010-03-17 2011-03-17 Nanoparticule de nickel-cobalt et procédé de fabrication associé

Country Status (4)

Country Link
JP (1) JP5830010B2 (fr)
KR (1) KR101671049B1 (fr)
CN (1) CN102811829B (fr)
WO (1) WO2011115214A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013181177A (ja) * 2012-02-29 2013-09-12 Jx Nippon Mining & Metals Corp コバルトめっき銅微粉及びコバルトめっき銅微粉を用いて製造した導電ペースト並びにコバルトめっき銅微粉の製造方法
JP2015138915A (ja) * 2014-01-23 2015-07-30 住友金属鉱山株式会社 積層コンデンサ用ニッケル系合金微粒子およびその製造方法
JP2017066525A (ja) * 2015-09-30 2017-04-06 新日鉄住金化学株式会社 銅−ニッケル−コバルト３元ナノ粒子及びその製造方法、焼結体、集電材並びに燃料電池
KR20170061659A (ko) 2014-09-30 2017-06-05 신닛테츠 수미킨 가가쿠 가부시키가이샤 니켈 입자의 제조 방법

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2568858C2 (ru) * 2013-10-24 2015-11-20 Федеральное государственное бюджетное образовательное учреждение высшего профессионального образования "Кемеровский государственный университет" (КемГУ) Наноструктурированный порошок твердого раствора кобальт-никель и способ его получения
CN106141171B (zh) * 2015-04-27 2018-06-05 中国科学院宁波材料技术与工程研究所 核壳型超结构纳米材料、其制备方法及应用
CN106834763B (zh) * 2017-01-05 2018-06-19 东南大学 一种超黑纳米柱状Co及其制备方法
CN110899718B (zh) * 2018-09-14 2022-11-15 上海铁路通信有限公司 一种大粒径壳核结构钴颗粒的制备方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008031104A (ja) * 2006-07-28 2008-02-14 Seiko Epson Corp ギ酸銅の製造方法、銅粒子の製造方法および配線基板の製造方法
JP2009270146A (ja) * 2008-05-02 2009-11-19 Shoei Chem Ind Co 銀超微粒子の製造方法
JP2009293126A (ja) * 2008-06-05 2009-12-17 Xerox Corp コア−シェル金属ナノ粒子を形成する方法

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH11233121A (ja) * 1998-02-18 1999-08-27 Yoyu Tansanengata Nenryo Denchi Hatsuden System Gijutsu Kenkyu Kumiai 溶融炭酸塩型燃料電池の空気極材料及びその製造方法
JP2003013103A (ja) * 2001-06-26 2003-01-15 Murata Mfg Co Ltd 導電粉末の製造方法、導電粉末、導電性ペーストおよび積層セラミック電子部品
US7704919B2 (en) * 2005-08-01 2010-04-27 Brookhaven Science Associates, Llc Electrocatalysts having gold monolayers on platinum nanoparticle cores, and uses thereof
JP5063003B2 (ja) * 2006-01-25 2012-10-31 株式会社日本触媒 銅ナノ粒子の製造方法、銅ナノ粒子、導電性組成物および電子デバイス

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2008031104A (ja) * 2006-07-28 2008-02-14 Seiko Epson Corp ギ酸銅の製造方法、銅粒子の製造方法および配線基板の製造方法
JP2009270146A (ja) * 2008-05-02 2009-11-19 Shoei Chem Ind Co 銀超微粒子の製造方法
JP2009293126A (ja) * 2008-06-05 2009-12-17 Xerox Corp コア−シェル金属ナノ粒子を形成する方法

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
TOMOHISA YAMAUCHI ET AL.: "Microwave-Assisted Synthesis of Monodisperse Nickel Nanoparticles Using a Complex of Nickel Formate with Long- Chain Amine Ligands", BULL. CHEM. SOC. JPN., vol. 82, no. 8, 2009, pages 1044 - 1051 *
YASUNORI TSUKAHARA ET AL.: "Heterogeneous reaction system using metal nanoparticle catalysts under microwave irradiation", SHOKUBAI, vol. 51, no. 6, 10 September 2009 (2009-09-10), pages 417 - 419 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013181177A (ja) * 2012-02-29 2013-09-12 Jx Nippon Mining & Metals Corp コバルトめっき銅微粉及びコバルトめっき銅微粉を用いて製造した導電ペースト並びにコバルトめっき銅微粉の製造方法
JP2015138915A (ja) * 2014-01-23 2015-07-30 住友金属鉱山株式会社 積層コンデンサ用ニッケル系合金微粒子およびその製造方法
KR20170061659A (ko) 2014-09-30 2017-06-05 신닛테츠 수미킨 가가쿠 가부시키가이샤 니켈 입자의 제조 방법
JPWO2016052067A1 (ja) * 2014-09-30 2017-07-20 新日鉄住金化学株式会社 ニッケル粒子の製造方法
JP2017066525A (ja) * 2015-09-30 2017-04-06 新日鉄住金化学株式会社 銅−ニッケル−コバルト３元ナノ粒子及びその製造方法、焼結体、集電材並びに燃料電池

Also Published As

Publication number Publication date
CN102811829A (zh) 2012-12-05
JPWO2011115214A1 (ja) 2013-07-04
KR101671049B1 (ko) 2016-10-31
JP5830010B2 (ja) 2015-12-09
KR20130056852A (ko) 2013-05-30
CN102811829B (zh) 2015-08-05

Similar Documents

Publication Publication Date Title
JP5830010B2 (ja) ニッケル−コバルトナノ粒子の製造方法
KR101635664B1 (ko) 니켈 나노 입자의 제조 방법
JP5068614B2 (ja) マイクロ波を用いた銅ナノ粒子の製造方法
JP2011214143A (ja) ニッケルナノ粒子の製造方法
JP5525301B2 (ja) 金属微粒子・金属酸化物微粒子の製造方法、金属微粒子・金属酸化物微粒子、並びに金属含有ペーストおよび金属膜・金属酸化物膜
Wang et al. Solution synthesis of triangular and hexagonal nickel nanosheets with the aid of tungsten hexacarbonyl
JP5818318B2 (ja) ニッケルナノ粒子の製造方法
JP5831967B2 (ja) 複合ニッケルナノ粒子及びその製造方法
JP2011214142A (ja) ニッケルナノ粒子の製造方法
JP2016160531A (ja) 有機化合物に分散された微粒子の集まりの製造と製造方法
JP2011214144A (ja) 金属複合ニッケルナノ粒子の製造方法
Songping et al. Preparation of ultra-fine copper–nickel bimetallic powders with hydrothermal–reduction method
JP5744580B2 (ja) 鉄酸化物を含有する金属複合ニッケルナノ粒子の製造方法及び鉄酸化物を含有する金属複合ニッケルナノ粒子
Singh et al. Glycerol mediated low temperature synthesis of nickel nanoparticles by solution reduction method
WO2013031670A1 (fr) Dispersant, et composition de nanoparticules métalliques susceptibles de dispersion
JP6603031B2 (ja) ニッケル粒子及びその製造方法
JP2013043159A (ja) 分散剤及び分散性金属ナノ粒子組成物
JP2013108141A (ja) 金属微粒子組成物及びその製造方法
JP2013043157A (ja) 分散剤及び分散性金属ナノ粒子組成物
JP2021188087A (ja) ニッケルナノ粒子凝集体、その製造方法及びニッケルナノ粒子複合基板
JP6608378B2 (ja) ニッケル粒子の製造方法
WO2016139967A1 (fr) Particules de nickel et procédé pour sa production et pâte électroconductrice
JP2013043160A (ja) 分散剤及び分散性金属ナノ粒子組成物
JP2013043158A (ja) 分散剤及び分散性金属ナノ粒子組成物
Guo et al. Preparation of Spherical Tungsten Particles Assisted by Hydrothermal Method

Legal Events

Date Code Title Description
WWE Wipo information: entry into national phase

Ref document number: 201180014315.6

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11756398

Country of ref document: EP

Kind code of ref document: A1

ENP Entry into the national phase

Ref document number: 20127021767

Country of ref document: KR

Kind code of ref document: A

WWE Wipo information: entry into national phase

Ref document number: 2012505745

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11756398

Country of ref document: EP

Kind code of ref document: A1