KR100555584B1 - The Fabrication of Metal Nanoparticles by Application of Electro-Decomposition Method - Google Patents

Abstract

The present invention is a method applying the electrolysis method without using an electrolyte such as a metal salt generally used in the production of nano-sized metal particles, using a small amount of additives and pure water, and by applying external energy such as ultrasonic or agitator from the outside nanoparticles To form and disperse.

The particle size of the metal produced by the present invention can be controlled by the manufacturing process from a few nm to more than 1000 nm, and there is no generation of harmful substances that can occur in the electrolysis or chemical methods generally using metal salts. And mass production is possible.

In addition, the present invention is a simple process step using only environmentally friendly processes and pure water, and can be mass-produced by size of the nano-metal particles.

Electrolysis, Nanoparticles, Metal Nanoparticles, Nanoparticles Manufacturing Method

Description

The fabrication of metal nanoparticles by application of electro-decomposition method

1 is a schematic configuration diagram showing an example apparatus for realizing a manufacturing method according to the present invention;

Figure 2 is an example of a full length radiation scanning electron micrograph for explaining the length growth occurring in the cathode during the silver powder manufacturing experiment,

3 is a transmission electron micrograph and a diffraction test result of silver nanoparticles as an example of the metal nanoparticles prepared by the manufacturing method according to the present invention,

4 is an X-ray diffraction experiment of the silver nanoparticles of FIG.

5a, 5b, and 5c are full-length scanning electron micrographs showing the size of the silver nanoparticles of FIG.

6 is a transmission electron micrograph and a diffraction test result of gold nanoparticles as another example of the metal nanoparticles prepared by the method according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: container 2: solution

3: electrode 4: ultrasonic generator

5: stirrer

The present invention relates to a method for producing metal nanoparticles using an electrolysis method, and more particularly, to produce nanoparticles of metals in an environmentally friendly manner, to effectively control the size of metal particles, and to produce metal powders in large quantities. It relates to a method for producing metal nanoparticles using a decomposition method.

Methods for obtaining fine metal powders include chemical methods such as coprecipitation, spraying, sol-gel, electrolysis, and reverse phase microemulsion, and mechanical methods such as grinding using a ball mill and a stamp mill. Is being used.

For example, a chemical method for preparing silver powder is a method of reducing silver oxide or silver hydroxide precipitated using a reducing agent such as hydrazine, hydrogen peroxide, or formalin to neutralize an aqueous solution of silver nitrate with an alkaline solution. It is mainly used to inhale the reduced gas such as hydrogen and carbon monoxide to precipitate the produced silver hydroxide and reduce it by adding a reducing agent such as formalin and oxalate to the aqueous solution of alkaline amine complex to reduce it to silver powder. do.

However, this conventional manufacturing method uses a metal salt as an electrolyte as a starting material, it is not environmentally friendly, takes a lot of cost and time to remove the harmful substances, there is a disadvantage that it is not easy to control the particle size.

In addition, conventionally, since surfactants and additives used to prevent particle growth due to aggregation of metal particles also use harmful substances, they are disadvantageous in that they are not environmentally friendly.

In the conventional general electrolysis method, particles are obtained by metallization on the electrode surface by electrolysis using an electrode of a metal material to be synthesized and a metal salt, ie, nitrate, carbonate, sulfate, etc. as an electrolyte.

Of course, the reason why the harmful metal salt is used as an electrolyte for obtaining the harmful metal powder in the electrolysis method is that the metal is not dissolved in water, and when the metal combined with the strong acid salt is dissolved in water, it can be easily dissociated into ions and granulated by a reducing agent. .

In this case, harmful substances are generated as by-products, and harmful gases are generated when the temperature is raised, so it is not environmentally friendly, and the size of particles is not uniform.

Furthermore, in the conventional electrolysis method using metal salts such as nitrate, carbonate, sulfate, etc., the starting material itself is not environmentally friendly, waste water treatment problems occur during neutralization and washing process, and there is a lot of washing process. In the process, a lot of metal powder is lost.

On the other hand, the mechanical method is widely used for grinding silver powder using a ball mill and a stamp mill, but the mechanical grinding method is inherently limited in miniaturization and is unsuitable for obtaining pure metal particles since it is likely to be contaminated during the process. .

The present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to use only the electrode and a small amount of additives, pure water, and by applying an external force, without using most of the harmful metal salts By inducing the formation and dispersion of metal particles, it is possible to produce nanoparticles of metals in an environmentally friendly manner, to effectively control the size of metal particles, and to use a metal electrolysis method to mass produce metal powders of uniform particles in a simple process. To provide a method for producing nanoparticles.

In order to realize this, in the present invention, in the preparation of metal into nanoparticles using electrolysis, the step of dissolving any one of environmentally friendly metal ion reducing agent and organic metal ion reducing agent in pure water (DI water) and dissolving the above, Two electrodes are spaced apart from each other in the solution, and the electrode is composed of the same components as the metal particles to be obtained and ionized in the solution by electricity, and the metal ions are reduced by the reducing agent in the solution to reduce the metal It provides a method for producing metal nanoparticles using an electrolysis method comprising the step of depositing particles, and the ultrasonic generator is disposed in the solution to disperse the metal particles in the solution in a uniform particle shape.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

The present invention uses an electrolysis method such as silver (Ag), gold (Au), platinum (Pt), palladium (Pd), copper (Cu), nickel (Ni), zinc (Zn), iron (Fe), etc. Nanoparticles of various sizes, that is, several nanometers to 1000nm, can be prepared by using a small amount of environmentally friendly reducing agents and pure water, and applying external energy such as ultrasonic waves or agitators. Formation of nanoparticles is to disperse in solution.

1 shows an example of an apparatus for explaining a metal nanoparticle manufacturing method using the electrolysis method according to the present invention, it is apparent that the position of each component can be variously changed.

Therefore, in the apparatus for producing metal nanoparticles to which the method of the present invention is applied, a solution 2 of pure water and additives is introduced into a container 1, and two electrode rods 3 are introduced into the solution 2. Spaced apart, it consists of a structure in which the ultrasonic generator 4 for emitting ultrasonic waves to the solution 2 and the stirrer 5 for stirring the solution 2 are arranged above and below the container 1, respectively.

Of course, in FIG. 1, both the ultrasonic generator 4 and the stirrer 5 are installed in the solution 2, but one of the ultrasonic generator 4 and the stirrer 5 may be installed in the solution 2. It may be.

In particular, the manufacturing method of the present invention is to use a solution (2) in which any one of the environmentally friendly metal ion reducing agent and the organic metal ion reducing agent as the additive is dissolved in pure water, the electrode rod (3) is the same as the metal particles to obtain It is composed of components and decomposed in the solution (2) by electricity, at least one of the ultrasonic generator 4 and the stirrer (5) is disposed in the solution (2) to uniform the metal particles in the solution (2) It is made to disperse | distribute to one particle shape.

The eco-friendly metal ion reducing agent is any one of trisodium citrate (TRISODIUM CITRATE), monosodium citrate (MONOSODIUM CITRATE), potassium citrate (POTASSIUM CITRATE), alcohol, the eco-friendly metal ion reducing agent is harmless to the human body 10 ppm to 10 ⁶ ppm of ion-reducing agent are added and dissolved in pure water.

The organic metal ion reducing agent is any one of hydrazine (HYDRAZINE), ethylene oxide (ETHYLENEOXIDE), and since these organic metal ion reducing agents are harmful to the human body in some small amount than the above-mentioned environmentally friendly metal ion reducing agent 10ppm ~ 10 ³ ppm is dissolved in pure water.

In other words, the present invention does not use an electrolyte harmful to the environment, and uses a small amount of applied voltage and eco-friendly metal ion reducing agent based on pure water, or even a small amount of the existing organic metal ion reducing agent, which is harmful to some extent, so it is simple. The metal nanoparticles can be sufficiently obtained by washing. The pure water refers to DI water, and refers to water having almost no anions and cations existing in tap water or bottled water, and when preparing metal nanoparticles, anions and cations which are impurities other than environmentally friendly metal ion reducing agents and organic metal ion reducing agents are contained. In this case, the above-mentioned DI water is used because impurities may occur in the nanometal particles, and metal particles cannot be obtained by forming a complex compound. In addition, limiting the numerical value as described above can be determined by the reaction time and temperature of nanoparticles of various sizes from several nm to 1,000 nm, one of the important factors is the amount of environmentally friendly metal ion reducing agent and organic metal ion reducing agent. At the same reaction temperature and reaction time, when the amount of reducing agent is small, fine particles are obtained, and when the amount is large, large particles are obtained. However, when the amount of the reducing agent is 10 ppm or less, the amount of the nanoparticles obtained is extremely small, and when the amount is 1,000 ppm or more, micron particles are obtained, and therefore, an appropriate value limitation is required to obtain metal nanoparticles.

Anyway, the atom needs energy to break the metal bond and ionize. At low voltage, the energy is insufficient and no reaction occurs, but if a voltage above the binding energy is applied, ions are released into the solution.

Therefore, in the present invention, when a voltage higher than the binding energy is applied to the metal rod 3 in the power supply 6, the metal cations emanating from the metal rod move to the cathode by electrostatic attraction to obtain electrons and particles.

In the state in which the ultrasonic generator 4 and the stirrer 5 are not in operation as shown in FIG. 2, the particles remain in the cathode.

Therefore, as the anion of the additive dissolved in the pure water is rapidly electrolyzed by one of the environmentally friendly metal ion reducing agent and the organic metal ion reducing agent as additives, the ionization energy of the metal is drastically lowered and the resistance of the power source is drastically reduced, thereby reducing the metal particles. Precipitation also increases rapidly, thereby enabling mass production of metal powders.

In particular, as shown in FIG. 2, the metal particles staying in the cathode are blocked by the ultrasonic generator 4 and the stirrer 5, and thus the particle size of the metal particles is small and uniformly formed as shown in FIGS. 5A, 5B, and 5C.

In addition, the ultrasonic generator 4 and the stirrer 5 prevent the aggregation of metal particles in the solution 2 and easily move ions to produce uniform nanoparticles.

3 and 4 are TEM photographs and XRD diagrams of silver powders obtained in an experiment in which silver is composed of the electrode 3, and it can be seen that fairly uniform silver particles within 20 nm are generated.

5A, 5B, and 5C are the results obtained from the experiment using silver as the electrode 3, and from this photograph, it can be seen that the particle size is several nm to several hundred nm.

In addition, FIG. 6 is a TEM photograph and a diffraction test result of the gold powder obtained in the experiment using gold as the electrode (3), it can be seen that the gold particles are generated and dispersed in a smaller size than the silver particles at about 5nm.

In other words, when the power source 6 is a direct current, the cations from which the electrode 3 connected to the positive electrode is dissolved are moved to the electrode 3 connected to the negative electrode by means of a static attraction force, thereby obtaining electrons and granulating the particles. They stay in the cathode, which not only leads to the growth of the metal particles in the longitudinal direction, but also reduces the surface area of the cathode, which gives other metal ions the opportunity to oxidize, further accelerating the length growth of the particles.

In addition, the ultrasonic wave generator 4 and the stirrer 5 prevent the retention at the cathode, thereby forming a small and uniform particle size.

Of course, in the present invention, to control the size of the metal particles to adjust the voltage, current and time.

In the present invention, the metal material to be obtained without such harmful substances is used as an electrode, and the metal ions are quickly metallized, and eco-friendly metal ion reducing agents that are harmless to the human body and organic metal ion reducing agents that are harmful to the human body to a certain extent are used, so simple washing Through the metal nanoparticles are obtained.

In addition, in order to prevent agglomeration of metallized particles, by applying external energy such as ultrasonic wave or agitator, environmentally friendly, economical and mass production is possible. The particle size and yield of the metal are determined by the area of the electrode, the temperature of the reactor, The amount of additives is controlled by the magnitude of the voltage.

In the present invention, when the metal nanoparticles are manufactured, the metal rods are directly ionized and granulated, and thus, not only silver and gold powders but also platinum (Pt), palladium (Pd), copper (Cu), and nickel (Ni) are produced. It is apparent that metals such as zinc (Zn), iron (Fe), and the like may be manufactured as nanoparticles.

Of course, the fine metal powder prepared by the present invention can be produced uniformly in an environment-friendly manner in a simple process, can be produced in large quantities by size, medical, clothing, cosmetics, catalysts, electrode materials, electronic materials, structural materials, etc. Likewise, it can be widely used in most of the applications we encounter.

As described above, the method for producing metal nanoparticles using the electrolysis method according to the present invention is to prepare metal particles by simply applying a voltage higher than the ionization energy of the metal to a small amount of additives and pure water without using an unfriendly metal salt. Therefore, there is an advantage that the nanoparticles of the metal can be easily manufactured in an environmentally friendly manner.

In addition, the present invention can effectively control the size of the metal particles by adjusting the voltage, current and reaction time, etc., environmentally friendly, using a small amount of additives to lower the ionization energy of the metal and mobility of the ions with an ultrasonic generator or agitator And by controlling the residence time of the metal particles in the negative electrode has the advantage that can be mass produced a uniform nano powder under a high voltage wide electrode.

Claims (5)

In the preparation of metal into nanoparticles using electrolysis, Either one of the environmentally friendly metal ion reducing agent and the organic metal ion reducing agent is dissolved in pure water (DI water), and the two electrode electrodes are spaced apart from each other in the solution, and the electrode has the same components as the metal particles to be obtained. Configured to be ionized in the solution by electricity, metal ions are reduced by the reducing agent in the solution to precipitate metal particles, and an ultrasonic wave generator is disposed in the solution to uniform the metal particles in the solution. Method for producing metal nanoparticles using an electrolysis method comprising the step of dispersing in a particle shape. The method of claim 1, The environmentally friendly metal ion reduction agent is a method for producing metal nanoparticles using an electrolysis method characterized in that any one of trisodium citrate, monosodium citrate, potassium citrate, alcohol. The method according to claim 1 or 2, Wherein the environmentally friendly metal ion reducing agent 10ppm ⁶ to 10 ppm is introduced in the pure water production method of metal nanoparticles using electrolytic method characterized in that the dissolution. The method of claim 1, The organic metal ion reduction agent is a metal nanoparticles manufacturing method using an electrolysis method, characterized in that any one of hydrazine, ethylene oxide. The method according to claim 1 or 4, The organic metal ion reducing agent 10ppm ³ to 10 ppm is added to the pure water using the method of metal nano-electrolytic method characterized in that the soluble particles made.

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