KR101566942B1 - Synthesis method of gallium oxide nanomaterials by using thermal plasma and the gallium oxide thereby - Google Patents
Synthesis method of gallium oxide nanomaterials by using thermal plasma and the gallium oxide thereby Download PDFInfo
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- KR101566942B1 KR101566942B1 KR1020140145144A KR20140145144A KR101566942B1 KR 101566942 B1 KR101566942 B1 KR 101566942B1 KR 1020140145144 A KR1020140145144 A KR 1020140145144A KR 20140145144 A KR20140145144 A KR 20140145144A KR 101566942 B1 KR101566942 B1 KR 101566942B1
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J12/00—Chemical processes in general for reacting gaseous media with gaseous media; Apparatus specially adapted therefor
- B01J12/002—Chemical processes in general for reacting gaseous media with gaseous media; Apparatus specially adapted therefor carried out in the plasma state
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G1/00—Methods of preparing compounds of metals not covered by subclasses C01B, C01C, C01D, or C01F, in general
- C01G1/02—Oxides
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G15/00—Compounds of gallium, indium or thallium
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J2219/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J2219/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
- B01J2219/0894—Processes carried out in the presence of a plasma
- B01J2219/0898—Hot plasma
Abstract
Description
The present invention relates to a method for producing gallium oxide powder using thermal plasma and gallium oxide produced thereby.
Gallium oxide (Ga 2 O 3 ) has a wide band gap of 4.8 eV. It can be applied to photodetector, luminescent phosphors, transparent electrode solar cell, and high-temperature chemical gas sensors. Gallium oxide is used not only for dielectric gates, phosphors, transparent conductive electrodes, etc., but also for gas sensors at high temperatures.
Generally, a precipitation method is used for synthesizing gallium oxide powder. When the gallium oxide powder is synthesized by the precipitation method, the calcination temperature is low, so that it is easy to produce and can be mass-produced at a time, which is industrially useful. However, the particle size of the gallium oxide powder is in the range of several to several tens of micrometers Mu m), and thus is not suitable for the production of powders of several tens of nanometers (nm).
As a method of synthesizing another gallium oxide powder, a conventional synthesis method using an electric furnace is generally carried out by placing the catalyst at the center of an electric furnace, adjusting the atmosphere, synthesizing the mixture by raising the temperature to the synthesis temperature, And then collecting gallium oxide as a synthetic material.
In such a case, it is not easy to obtain and evaluate the synthesis behavior or the result of the precise nanomaterial at a certain temperature since the catalyst is already exposed to a temperature different from the actual synthesis temperature in the temperature rise before the temperature to be synthesized is reached .
Korean Patent Laid-Open Publication No. 10-2013-0131619 discloses a method for producing gallium oxide powder, and more particularly, to a method for producing gallium oxide powder by mixing a solvent and a chelating agent, Adding a metal ion material containing a gallium (Ga) component to the resultant solution in which the chelating agent is dissolved and stirring to obtain a transparent solution; adjusting the pH of the transparent solution A step of heating the transparent solution whose pH is adjusted to a first temperature to proceed with polyesterification to form a polymer complex; and a step of pulverizing the polymer complex and a step of pulverizing the polymer complex to a second Thereby forming a gallium oxide powder. The present invention also provides a method for producing gallium oxide powder.
In the present invention, in order to solve the above problems, a gallium oxide powder was prepared by using a thermal plasma jet while preparing gallium oxide, which is a stable bonding structure, and completed the present invention.
It is an object of the present invention to provide a method for producing gallium oxide powder using thermal plasma and gallium oxide produced thereby.
In order to achieve the above object,
The present invention
Generating a thermal plasma jet by supplying a thermal plasma generating gas (step 1);
Supplying a raw material solution containing gallium nitrate hydrate (Ga (NO 3 ) 3 .xH 2 O) to the thermal plasma jet generated in
And cooling and collecting the vaporized vapor in the step 2 (step 3).
Further, according to the present invention,
A gallium oxide powder produced by the above method is provided.
The method of manufacturing gallium oxide powder using thermal plasma according to the present invention can synthesize nano-sized gallium oxide powder in a short time, and it is easy to vaporize by using high temperature plasma, and high process efficiency and control of process conditions are easy And the continuous process can be effected as the process is performed under atmospheric pressure conditions.
1 is a schematic view of a plasma apparatus for synthesis of gallium oxide powder according to the present invention;
2 is a graph showing X-ray diffraction (XRD) results of the gallium oxide powder prepared in Examples 1 to 4;
3 is a photograph and a graph showing the results of transmission electron microscopy and energy dispersion spectroscopy (TEM-EDS) of gallium oxide prepared in Examples 3 and 4;
4 is a photograph of the gallium oxide prepared in Examples 1 to 4 through a transmission electron microscope.
Hereinafter, the present invention will be described in detail.
The present invention
Generating a thermal plasma jet by supplying a thermal plasma generating gas (step 1);
Supplying a raw material solution containing gallium nitrate hydrate (Ga (NO 3 ) 3 .xH 2 O) to the thermal plasma jet generated in
And cooling and collecting the vaporized vapor in the step 2 (step 3).
Hereinafter, the method for producing gallium oxide powder according to the present invention will be described in detail for each step.
In the method for producing gallium oxide powder according to the present invention,
FIG. 1 is a schematic view of a plasma apparatus for synthesizing gallium oxide powder. The plasma apparatus can be roughly implemented using a power source, a torch, which is a plasma generator, a reaction tube, a reaction chamber, and a syringe pump for injecting a raw material. have.
The thermal plasma is a gas composed of electrons, ions, and neutral particles generated mainly by arc discharge, and has a high-speed jet flame having a particle size of 1,000-20,000 ° C and 100-2,000 m / s. The gallium oxide nano powder can be produced using the characteristics of the thermal plasma having such a high heat capacity, high speed and a large amount of active particles.
At this time, the thermal plasma generating gas in the
Next, the
The gallium nitrate hydrate used as a raw material for producing the gallium oxide powder according to the present invention is a compound containing a large amount of gallium and provides both gallium and an oxygen source for gallium oxide synthesis. In addition, in comparison with conventional gallium or gallium nitride for the synthesis of gallium oxide, it is an economical base material because it is a very cheap raw material. These base materials can be diluted in solution and injected into the plasma apparatus in liquid form. At this time, water (H 2 O) or methyl alcohol (CH 3 OH) is preferable as the solution.
Also, nitrogen gas may be used as a carrier gas to supply the raw material solution containing the nitrate hydrate. For example, the raw material solution and a nitrogen gas at a flow rate of about 1 to 5 L / Can be injected into the nozzle through the anode in the plasma torch at a constant injection rate and can easily penetrate into the high temperature part of the plasma jet.
Further, in the method for producing a gallium oxide powder according to the present invention, the step 3 is a step of cooling and collecting the vaporized vapor in the
As shown in FIG. 1, the injected gallium nitrate hydrate is vaporized and decomposed in the high temperature region inside the torch and is synthesized as gallium oxide. The synthesized gallium oxide vapor condenses on the inner cold surface of the reaction tube to become nano powder, The gallium oxide vapor entering the reaction chamber through the reaction tube condenses into the cold lid of the reaction chamber and becomes a nano powder.
As shown in Fig. 1, a narrow and small reaction tube was placed on a large reaction chamber, and collected on the inner surface of the reaction tube and the upper lid of the reaction chamber when collecting the synthesized gallium oxide powder. At this time, in the case of the powder collected in the reaction chamber, amorphous gallium oxide powder is collected, and crystalline gallium oxide powder can be collected in the reaction tube.
In addition, when the raw material solution in
On the other hand, the crystal size of the gallium oxide powder synthesized from the raw material solution containing methyl alcohol is about twice as large as that of the powder synthesized from the raw material solution containing water.
This is because different gases and ions are generated in water and methyl alcohol when they are vaporized and decomposed in a high-temperature plasma jet at a temperature of 10,000 ° C. or higher, and these influence the synthesis of gallium oxide.
In the case of water, oxygen gas (O 2 ), hydrogen gas (H 2 ) and hydroxide ion (OH) are generated from 1800 K or more, and oxygen (O) and hydrogen (H) radicals are generated from 2500 K or more
On the other hand, in the case of methyl alcohol, from less than 500 K readily decomposes to water (H 2 O) and hydrogen (H 2), from more than 500 K is-containing gas (methane (CH 4), carbon dioxide (CO 2 carbons), Carbon monoxide (CO)). The carbon-containing gas is a gas with a higher thermal conductivity than hydrogen or oxygen gas, which has an effect of increasing the heat transfer effect in a chemical reaction for oxidation.
Therefore, in the method for producing gallium oxide powder according to the present invention, crystalline and amorphous gallium gallium nano-particles and nanowires can be selectively synthesized by different kinds of solutions mixed with the raw materials to be supplied and their collecting positions .
Also,
A gallium oxide powder produced by the above method is provided.
The gallium oxide powder produced according to the present invention is in the form of nanoparticles or nanowires.
Depending on the position to be collected, the gallium oxide powder may also be crystalline (? - gallium oxide) or an amorphous form.
Hereinafter, the present invention will be described in more detail with reference to the following examples. It should be noted, however, that the following examples are illustrative of the invention and are not intended to limit the scope of the invention.
≪ Example 1 > Preparation of gallium oxide powder using
Step 1: In order to produce gallium oxide powder, a plasma apparatus was used as a power source, a torch as a plasma generator, a reaction tube, a reaction chamber, and a syringe pump for injecting a raw material as shown in FIG. Table 1 shows the results.
Plasma jets were generated using 13 L / min of argon and 2 L / min of nitrogen gas, and the injected power was fixed at 10.8 kW (300 A, 36 V).
Step 2: 2 g of gallium nitrate hydrate as a starting material was diluted with 8 ml of water (H 2 O), and the solution was injected at a rate of 0.4 ml / min using a syringe pump together with 3 L / min nitrogen gas It was constantly infused.
The liquid raw material was injected into a 2 mm nozzle passing through the anode in the plasma torch, and then it was permeated into the high temperature part of the plasma jet and vaporized.
Step 3: The vaporized vapor in
Example 2: Production of gallium oxide powder using
A gallium oxide powder was produced in the same manner as in Example 1, except that the gallium oxide powder was collected in the reaction chamber in the step 3 of the above Example 1. The inner diameter and the length of the reaction chamber are 300 mm and 300 mm, respectively.
≪ Example 3 > Preparation of gallium oxide powder using thermal plasma 3
In the same manner as in Example 1 except that 2 g of gallium nitrate hydrate as a raw material was diluted and injected into 8 ml of methyl alcohol (CH 3 OH) in the
Example 4 Production of Gallium Oxide Powder Using Thermal Plasma
A gallium oxide powder was produced in the same manner as in Example 3 except that gallium oxide powder was collected in a reaction chamber.
Experimental Example 1 X-ray diffraction analysis of gallium oxide powder
X-ray diffraction (XRD) was performed for crystal analysis of the gallium oxide powder prepared in Examples 1 to 4, and the results are shown in FIG.
2 shows XRD peaks of the products synthesized by the two solutions (water, methyl alcohol) for each trapping position (reaction tube and reaction chamber). Fig. 2 (a) And FIG. 2 (b) shows the XRD pattern of the gallium oxide powder prepared in Examples 2 and 4, which were collected in the reaction chamber.
As shown in Fig. 2 (a), in the case of the powder collected in the reaction tube, gallium oxide was synthesized in the β crystal phase in both of water and methyl alcohol solution.
On the other hand, as shown in Fig. 2 (b), in the case of the powder collected in the reaction chamber, it can be confirmed that an amorphous substance having no specific crystal peak is synthesized in both solutions (water and methyl alcohol).
Experimental Example 2 Transmission electron microscopy and energy dispersion spectroscopic analysis of gallium oxide powder
In order to identify the components of gallium oxide synthesized from gallium nitrate hydrate diluted in methyl alcohol, gallium oxide prepared in Examples 3 and 4 was analyzed by transmission electron microscopy and energy dispersive spectroscopy (TEM) EDS). The results are shown in FIG.
FIG. 3 (a) shows the gallium oxide of Example 3 captured in the reaction tube, and FIG. 3 (b) shows the TEM-EDS results of the gallium oxide of Example 4 captured in the reaction chamber.
As can be seen from FIG. 3, it can be seen that both the powder collected in the reaction tube and the reaction chamber do not have elements other than gallium and oxygen. Therefore, along with the XRD results of Experimental Example 1, crystalline gallium oxide was synthesized in the reaction tube and amorphous gallium oxide was synthesized in the reaction chamber.
Experimental Example 3: Analysis of crystal size of gallium oxide powder
To determine the crystal size of the gallium oxide powder synthesized from the two solutions of water and methyl alcohol, the gallium oxide produced in Examples 1 and 3 collected in the reaction tube was calculated through the XRD peak shown in FIG. 2, Table 2 shows the results.
As shown in Table 2, it was confirmed that the crystal size of the gallium oxide powder synthesized by diluting methyl alcohol was about 2.3 times larger than that of the synthesized gallium oxide powder diluted with water.
It can be considered that when gases injected from a high-temperature plasma jet at a temperature higher than 10,000 ° C are vaporized and decomposed, different gases and ions are generated in water and methyl alcohol, and the influence of these gases on the synthesis of gallium oxide is considered.
In the case of water, oxygen gas (O 2 ), hydrogen gas (H 2 ) and hydroxide ion (OH) are generated from above 1800 K and oxygen (O) and hydrogen (H) radicals are generated from above 2500 K.
On the other hand, in the case of methyl alcohol, from less than 500 K readily decomposes to water (H 2 O) and hydrogen (H 2), from more than 500 K is-containing gas (methane (CH 4), carbon dioxide (CO 2 carbons), Carbon monoxide (CO)). The carbon-containing gas is a gas with a higher thermal conductivity than hydrogen or oxygen gas, because it affects the heat transfer effect in the chemical reaction for oxidation.
EXPERIMENTAL EXAMPLE 4 Transmission electron microscopic analysis of gallium oxide powder
FIG. 4 is a photograph of the gallium oxide obtained in Examples 1 to 4, observed through a transmission electron microscope.
Fig. 4 (a) shows gallium oxide of Example 1, (b) shows gallium oxide of Example 2, (c) shows gallium oxide of Example 3, It is a photograph observing through.
In the method for producing gallium oxide powder using the thermal plasma according to the present invention, the injected gallium nitrate hydrate is vaporized and decomposed in the high temperature region inside the torch to be synthesized as gallium oxide, Condensed on a cold surface to become a nano powder, or a gallium oxide vapor which enters a reaction chamber through a reaction tube is condensed into a cold lid of the reaction chamber to become a nano powder.
At this time, gallium oxide synthesized in the reaction chamber has a longer residence time than that of the gallium oxide synthesized in the reaction tube, and thus it can be seen that the growth time has been longer. Therefore, regardless of the kind of the solution, the size of the powder collected in the reaction chamber is larger than that of the powder collected in the reaction tube. But the shape of the powder was different.
(A) and (b) diluted in water as shown in FIG. 4, nanoparticles of about 10 nm in the case of (a) collected in the reaction tube were synthesized, and , Larger nanoparticles of about 50 nm were synthesized.
In (c) and (d) diluted with methyl alcohol, nanoparticles of about 30 nm were synthesized in the reaction tube (c), but in the reaction chamber (d) It can be seen that the nanowires are synthesized.
As shown in FIGS. 4 (a) and 4 (c), in the case of powder collected in a reaction tube, nanoparticles were synthesized irrespective of the kind of the solution.
In this case, in the case of Fig. 4 (c) using a solution containing methyl alcohol, it is characterized in that it decomposes to produce a highly thermally conductive carbon-containing gas. Thus, the synthesized powder is much larger than that of Fig. 4 Size can be confirmed.
On the other hand, as shown in FIGS. 4 (b) and 4 (d), the powder collected in the reaction chamber had different shapes depending on the kind of the solution. In the case of (b), which is a raw material diluted in water, the reaction tube was able to withstand a longer growth time, and maintained its shape and increased in size. However, in the case of (d) which is a raw material diluted with methyl alcohol, it grew in the form of nanowires instead of spherical nanoparticles when grown through a reaction tube.
As a result, when the raw material was diluted with water, the nanoparticles were synthesized in both the reaction tube and the reaction chamber. However, when the raw material was diluted with methyl alcohol, nanoparticles were synthesized in the reaction tube and nanowires were synthesized in the reaction chamber.
As a result, it was confirmed that crystalline and amorphous nanoparticles and nanowires can be selectively synthesized by varying the dilution solution.
Claims (9)
Supplying a raw material solution containing gallium nitrate hydrate (Ga (NO 3 ) 3 .xH 2 O) to the thermal plasma jet generated in step 1 and vaporizing (step 2); And
Step for cooling and collecting the vapor vaporized in the step 2 (step 3); gallium oxide (Ga 2 O 3) The method for producing a powder comprising a.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101835726B1 (en) | 2016-12-15 | 2018-03-07 | 인하대학교 산학협력단 | Method of manufacturing of cerium oxide nanopowder and Apparatus of manufacturing of cerium oxide nanopowder |
| KR20200060914A (en) * | 2018-11-23 | 2020-06-02 | 주식회사 퀀타머티리얼스 | VAPORIZATION METHOD FOR A Ga2O3 POWDER AND MANUFACTURING FOR A Ga2O3 NANO-POWDER USING THE SAME |
| KR20210036608A (en) | 2019-09-26 | 2021-04-05 | 주식회사 퀀타머티리얼스 | Manufacturing apparatus of gallium oxide powder for continuous production |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101835726B1 (en) | 2016-12-15 | 2018-03-07 | 인하대학교 산학협력단 | Method of manufacturing of cerium oxide nanopowder and Apparatus of manufacturing of cerium oxide nanopowder |
| KR20200060914A (en) * | 2018-11-23 | 2020-06-02 | 주식회사 퀀타머티리얼스 | VAPORIZATION METHOD FOR A Ga2O3 POWDER AND MANUFACTURING FOR A Ga2O3 NANO-POWDER USING THE SAME |
| KR102165563B1 (en) | 2018-11-23 | 2020-10-14 | 주식회사 퀀타머티리얼스 | VAPORIZATION METHOD FOR A Ga2O3 POWDER AND MANUFACTURING FOR A Ga2O3 NANO-POWDER USING THE SAME |
| KR20210036608A (en) | 2019-09-26 | 2021-04-05 | 주식회사 퀀타머티리얼스 | Manufacturing apparatus of gallium oxide powder for continuous production |
| KR102292258B1 (en) | 2019-09-26 | 2021-08-24 | 주식회사 퀀타머티리얼스 | Manufacturing apparatus of gallium oxide powder for continuous production |
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