KR20200014629A - Method of forming Manganese-doped maghemite-based/hematite-based iron oxides nanoparticle - Google Patents

Abstract

The present invention provides an easy method for manufacturing manganese hematite-based iron oxide nanoparticles as well as thermally stable manganese maghemite-based iron oxide nanoparticles. The method for manufacturing manganese maghemite-based or manganese hematite-based iron oxide nanoparticles comprises the following steps of: preparing a metal oxide aqueous solution containing iron oxide and manganese oxide (S1); adding an organic compound constituting FeMn-MOF (S2); forming the manganese/iron metal-organic framework (FeMn-MOF) (S3); and obtaining manganese maghemite- or manganese hematite-based iron oxide nanoparticles by thermal decomposition (S4).

Description

Manufacturing method of manganese maghemite iron oxide nanoparticles and manganese hematite iron oxide nanoparticles {Method of forming Manganese-doped maghemite-based / hematite-based iron oxides nanoparticle}

The present invention provides a very easy thermally stable maghemite-based (γ-Fe ₂ O ₃ ) iron oxide nanoparticles and hematite-based (α-Fe ₂ O ₃ ) iron oxide nanoparticles using a coordination polymer introduced with manganese and iron It is about how to.

Maghemite (γ-Fe ₂ O ₃ ) is a form of iron oxide, which, like ferrite, has a spinel structure and shows perimagnetic properties. However, maghemite (γ-Fe ₂ O ₃ ) is structurally unstable and easily changes to hematite structure. To prevent this, the thermal properties of the structure are maintained while maintaining the superparamagnetic properties through the introduction of other metal elements such as manganese. Increase stability. These maghemite-based iron oxides have been reported to effectively remove harmful nitrogen oxides when ammonia is used as a reducing agent. In addition, maghemite-based iron oxide has been reported to vary in catalytic activity according to the type of metal to be doped, it is analyzed that the tetrahedral structure of maghemite is the catalytic active site.

Hematite (α-Fe ₂ O ₃ ) is a hexagonal structure at the center of rhombohedral and is filled with divalent iron trivalent ions of octahedral. Hematite (α-Fe ₂ O ₃ ) exhibits ideal antiferromagnet properties at temperatures below 260K for bulk structures and weak ferromagnets or offset antiferromagnetic magnets at temperatures above 260K. Show enemy nature. Hematite structure is the most thermally stable structural form of iron oxide composed of divalent and trivalent, and is widely applied in fields such as photocatalysts.

On the other hand, metal oxide manufacturing method using the thermal decomposition of the metal-organic framework (MOF) is very easy and easy to mass production. However, a method of generating maghemite based on pyrolysis from MOF is generally manufactured in a non-oxygen atmosphere such as nitrogen and it has been reported that a hematite based structure is formed upon heat treatment in an oxygen atmosphere. Thermal conversion of MOF is influenced by metal species, physical properties of MOF scaffolds, temperatures, atmospheric conditions, and physical atmospheres, and studies have continued, but specific mechanisms or causes It is still insufficiently understood. However, various methods of preparing γ-Fe ₂ O ₃ by MOF pyrolysis have been known to require an oxygen-free atmosphere or a reducing process.

One problem to be solved in the present invention, (1) to provide a method for producing a precursor MOF without the addition of nitric acid and control of pH. In addition, another problem to be solved in the present invention, (2) by forming only the MOF containing manganese and iron, by controlling only the sintering temperature while maintaining a high manganese introduction ratio of maghemite-based (γ-Fe ₂ O ₃ ) iron oxide nanoparticles and / or hematite-based (γ-Fe ₂ O ₃ ) to provide a method for obtaining iron oxide nanoparticles.

In addition, another problem to be solved in the present invention is (3) manganese-doped maghemite ('manganese maghemite') and / or manganese-doped hematite ('manganese hematite') in the oxygen atmosphere It is to provide a method for producing.

Another problem to be solved by the present invention is (4) eco-friendly manufacturing process that uses water as a solvent and produces NaCl instead of hydrochloric acid or nitric acid as a by-product, which does not harm the human body and reduces the environmental pollution such as waste water generation. To provide.

The present invention relates to a method for preparing maghemite-based (γ-Fe ₂ O ₃ ) iron oxide nanoparticles and / or hematite-based (γ-Fe ₂ O ₃ ) iron oxide nanoparticles. The first aspect of the present invention is directed to the above method, the method comprising the steps of: (S1) preparing a metal ion aqueous solution containing iron and manganese ions; (S2) adding an organic compound to the aqueous metal ion solution; (S3) forming a manganese / ferrous metal-organic framework (FeMn-MOF); And (S4) pyrolysing the formed manganese / iron metal-organic framework (FeMn-MOF) to obtain maghemite iron oxide nanoparticles or manganese hematite iron oxide nanoparticles.

According to a second aspect of the present invention, in the first aspect, all the steps of the manufacturing method are performed under an atmospheric atmosphere, an atmospheric atmosphere containing oxygen, or an oxygen atmosphere.

According to a third aspect of the present invention, in the first or second aspect, the metal ion in the aqueous solution is included at a concentration of 0.1 mol / liter to 1.0 mol / liter.

In a fourth aspect of the present invention, in any one of the aforementioned aspects, the manganese ion concentration and the iron ion concentration in the aqueous solution are the same.

In a fifth aspect of the invention, in any one of the foregoing aspects, the organic compound comprises an organic acid.

In a sixth aspect of the present invention, in any one of the aforementioned aspects, the organic compound is introduced in the same amount as the concentration of the total metal ions contained in the aqueous solution.

In a seventh aspect of the present invention, in any one of the aforementioned aspects, the sintering is performed at a temperature range of 320 ° C. to 400 ° C., and the final product obtained is manganese maghemite-based iron oxide nanoparticles.

In an eighth aspect of the present invention, in any one of the aforementioned aspects, the sintering is performed at a temperature range of 600 ° C. to 800 ° C., and the final product obtained is manganese hematite iron oxide nanoparticles.

Manganese maghemite-based iron oxide nanoparticles and / or manganese hematite-based iron oxide nanoparticles obtained in the present invention are more eco-friendly and inexpensive than conventional vanadium-based nitrogen oxide reduction catalysts, and have superior performance in reducing iron oxide-based nitrogen oxides. It can be used as a catalyst and can be used as a storage medium and an electronic material through various magnetic properties.

The present invention develops a method for synthesizing MOF in which manganese and iron are introduced, and thermally stabilizes manganese hematite iron oxide nanoparticles and manganese hematite iron oxide nanoparticles through thermal decomposition thereof, thereby thermally introducing manganese ions. Since the stability is improved and does not require reaction conditions such as inert gas and many solvents, it is very easy to prepare manganese maghemite-based iron oxide nanoparticles and manganese hematite-based iron oxide nanoparticles in large quantities. The manganese maghemite iron oxide nanoparticles prepared according to the production method of the present invention are obtained by sintering in air and can maintain a maghemite structure without being denatured with hematite even at a high sintering temperature of up to 400 ° C.

Conventional iron oxide denitrification catalysts are known as vanadium alternative selective catalytic reduction (SCR) denitrification catalysts because they are cheaper and less toxic than vanadium-based denitrification catalysts, but are less thermally stable and not easy to manufacture. The disadvantages needed to be solved. However, the iron oxide-based denitrification catalyst can be manufactured easily by the method of the present invention, which is easy to manufacture, and has excellent performance and economy, and its application as a magnetic material is made possible due to high magnetism. In addition, hematite iron oxide nanoparticles are known to have excellent performance as photocatalysts, and thus may be applied in various photocatalyst fields.

In addition, the method of manufacturing the maghemite-based iron oxide nanoparticles and manganese hematite-based iron oxide nanoparticles according to the present invention is that NaCl is generated as a by-product when Mn-MOF is formed, there is little impact on the environment and human body.

1 is a schematic diagram showing the manufacturing process of manganese maghemite- and manganese hematite-iron oxide nanoparticles.
Figure 2 (a) is an SEM image of the FeMn-320 MOF prepared in Example 1, Figure 2 (b) is a TEM image of the FeMn-320 MOF, Figure 2 (c) is an EDS of the FeMn-320 MOF The mapping image.
3 is an FT-IR graph of (a) sodium fumarate, (b) Mn-MOF, (c) FeMn-MOF, and (d) Fe-MIL-88A used in the examples of the present invention.
4 is a graph of powder X-ray diffraction (XRD) of FeMn-320, FeMn-400, FeMn-600, and FeMn-800 prepared in Examples 1 to 4. FIG.
5 is a TGA (Thermogravimetric analysis) graph of FeMn-MOF obtained in Preparation Example 1. FIG.
Figure 6 (a) is an XPS graph of the manganese of FeMn-MOF obtained in Preparation Example 1 and Mn-MOF obtained in Comparative Example 2, Figure 6 (b) is a product obtained in Examples 1 to 4 (manganese Maghemite or manganese hematite), Figure 6 (c) is an XPS graph for iron of the product obtained in Preparation Example 1 and Comparative Example 2, Figure 6 (d) is in Examples 1-4 XPS graph of the product obtained.
Each of FIGS. 7A-7D is a TEM image of the product obtained in Examples 1-4.
8 (a) to 8 (d) are graphs of nitrogen adsorption and desorption analysis of the products obtained in Examples 1 to 4, respectively.
9 (a) shows the magnetic properties of the products obtained in Examples 1 to 4 in one graph, and FIGS. 9 (b) to 9 (e) are obtained in Examples 1 to 4. Graph showing the magnetic properties of each of the resulting products.
10 (a) to 10 (d) are each EDS mapping images showing the products obtained in Examples 1 to 4 using STEM.
11 is a result of analyzing the denitrification catalyst characteristics of the product obtained in Examples 1 to 4 by injecting ammonia reducing agent.
Figure 12 shows the content of each component contained in FeMn-MOF obtained in Preparation Example 1.

The objects, specific advantages and novel features of the present invention will become more apparent from the following detailed description and preferred embodiments associated with the accompanying drawings. In addition, the present invention may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein. In describing the present invention, detailed descriptions of related well-known technologies that may unnecessarily obscure the subject matter of the present invention will be omitted.

According to one aspect of the present invention, a method for producing manganese maghemite-based iron oxide nanoparticles or manganese hematite-based iron oxide nanoparticles, (S1) preparing a metal ion aqueous solution containing iron ions and manganese ions; (S2) adding an organic compound to the aqueous metal ion solution; (S3) forming a manganese / ferrous metal-organic framework (FeMn-MOF); And (S4) sintering to pyrolyze to obtain manganese maghemite iron oxide nanoparticles or manganese hematite iron oxide nanoparticles.

In particular, the production method of the present invention is characterized in that FeMn-MOF is prepared without addition of hydrochloric acid or nitric acid and without pH adjustment, and all processes are performed under an oxygen atmosphere. Hereinafter, each step will be described in more detail.

First, an aqueous metal ion solution containing iron ions and manganese ions is prepared (S1).

The aqueous metal ion solution may be prepared by dissolving iron and manganese metals in the form of metal salts, chlorides of metals, nitrides, bromide, sulfides, and the like in an aqueous solution. Non-limiting examples of iron include Iron (III) nitrate nonahydrate, Iron (III) bromide, Iron (III) trifluoromethanesulfonate, and Manganese (II) nitrate hexahydrate and Manganese (II) acetate hexahydrate. However, the present invention is not particularly limited thereto. In one embodiment of the invention, the aqueous metal ion solution may be prepared by dissolving FeCl ₃ .6H ₂ O and MnCl ₂ .4H ₂ O in water.

In one embodiment of the present invention, the concentration of metal ions in the aqueous solution may be included in the range of 0.1 mol / liter to 1.0 mol / liter, preferably 0.2 mol / liter to 0.5 mol / liter for each of manganese and iron In this case, the manganese and iron in the aqueous solution are included in the same number of moles. For example, when the water in the aqueous solution is 4L Using MnCl ₂ .4H ₂ O197g to 1 molar amount with FeCl ₃ .6H ₂ O1 moles relative to the ₃ .6H ₂ O with or FeCl ₂ .4H ₂ O can be used MnCl the same molar amount.

Next, the organic compound is added to the aqueous metal ion solution obtained in the above-mentioned step (S2). In one embodiment of the invention the organic compound may comprise an organic acid. The organic acid is not particularly limited, but may include, for example, at least one selected from sodium fumarate, fumaric acid, terephtalic acid, and sodium terephthalate. In one embodiment of the present invention, sodium fumarate may be used as the organic acid. In this step, the organic acid is added to the aqueous metal ion solution, and the organic acid, manganese ions, and iron ions are combined to form a FeMn-MOF precursor. In one embodiment of the present invention, the organic acid may be added in the same number of moles or more than the metal ions added to the aqueous solution. That is, it may be added in the same amount or in excess of the concentration (molar number) of the manganese ions and iron ions introduced. For example, sodium fumarate can be added in an amount of 320 g or 2 moles, relative to ₁ mole of FeCl ₃ .6H ₂ O.

Thereafter, manganese / iron metal-organic framework (FeMn-MOF) is formed (S3).

The aqueous solution obtained in (S2) is stirred for 6 hours to 12 hours in the temperature range of 60 ℃ to 80 ℃. Through this process, manganese / iron metal organic framework (FeMn-MOF) is formed. The aqueous solution is centrifuged and washed with deionized water and acetone to obtain manganese / iron metal-organic framework (FeMn-MOF) from the aqueous solution.

Thereafter, the obtained manganese / iron metal-organic framework (FeMn-MOF) is pyrolyzed by high temperature sintering to obtain manganese maghemite iron oxide nanoparticles or manganese hematite iron oxide nanoparticles (S4). In one embodiment of the present invention, the sintering may have different temperature conditions depending on the nature of the particles to be obtained. In the present invention, when the sintering temperature is performed in the temperature range of about 320 ° C to about 400 ° C, manganese maghemite iron oxide nanoparticles may be obtained. In addition, manganese hematite iron oxide nanoparticles can be obtained when the sintering temperature is higher than the above, preferably about 600 ° C. or more, for example, in the range of 600 ° C. to 800 ° C.

In one embodiment of the present invention, the manganese maghemite iron oxide nanoparticles obtained by heating the metal-organic skeleton (FeMn-MOF) obtained above to a temperature range of 320 ℃ to 400 ℃ at a temperature increase rate of 5 ℃ / min It can then be obtained by holding for about 30 minutes to 1 hour in each temperature range. In addition, the manganese hematite iron oxide nanoparticles were heated in the temperature range of 5 ° C./min to 600 ° C. or 800 ° C. at a temperature increase rate of 5 ° C./min. When sintered for 1 to 1 hour, manganese hematite particles are obtained. On the other hand, the sintering may be performed in an atmospheric atmosphere or an oxygen atmosphere or an atmosphere containing oxygen. When oxygen is included in the sintering gas, the concentration of oxygen may be maintained in the range of 1 vol% to 20 vol% in 100 vol% of the sintering gas while the sintering is in progress.

The present invention also provides manganese maghemite and manganese hematite obtained by the aforementioned method. Manganese maghemite according to the present invention is a high doping amount of manganese, the content of manganese up to 30% by weight compared to 100% by weight of maghemite. In addition, the manganese maghemite according to the present invention has a specific surface area of 40 m ² / g to 70 m ² / g, which is significantly higher than that of the manganese maghemite obtained by the conventional method, and is expected to have high catalytic activity.

On the other hand, hematite according to the present invention exhibits a magnetic property in which ferro-para is mixed with magnetic properties, rather than superparamagnetic magnetic properties previously reported.

Hereinafter, the present invention will be described in more detail with reference to the following Examples / Comparative Examples, but the following Examples / Comparative Examples are merely illustrative for easier understanding of the present invention, and are not limited thereto.

Example

Production Example  One

40 mL of distilled water was added to a glass jar with a lid and dissolved by adding 1.35 g (5 mmol) of FeCl ₃ .6H ₂ O and 0.99 g (5 mmol) of MnCl ₂ .4H ₂ O. Then sodium fumarate (1.6 g, 10 mmol) was dissolved in 40 mL of distilled water and slowly added. Thereafter, the mixture was stirred at 60 ° C. for 6 hours to synthesize iron / manganese dissimilar metal metal-organic framework (FeMn-MOF).

Example 1: FeMn Manufacture of -320

Thereafter, the iron / manganese metal-organic skeleton obtained in the above production example was put in a ceramic boat, and the temperature was raised at a rate of 5 ° C./min, and sintered at 320 ° C. under air conditions for about 1 hour to obtain manganese maghemite powder. The manganese maghemite obtained in Example 1 was named 'FeMn-320' according to the sintering temperature.

Example 2: FeMn Manufacture of -400

Except that the sintering temperature to 400 ℃ to prepare a manganese maghemite in the same manner as in Example 1, it was named 'FeMn-400'.

Example 3: FeMn Manufacture of -600

Manganese hematite was prepared in the same manner as in Example 1 except that the sintering temperature was set at 600 ° C., which was named “FeMn-600”.

Example 4: FeMn Manufacture of -800

Manganese hematite was prepared in the same manner as in Example 1 except that the sintering temperature was 800 ° C., which was named “FeMn-800”.

Comparative Example 1 Preparation of Fe-MIL-88A

40 mL of distilled water was added to the glass jar with a lid and dissolved by adding 1.35 g (5 mmol) of FeCl ₃ .6H ₂ O. Then sodium fumarate (1.6 g, 10 mmol) was dissolved in 40 mL of distilled water and slowly added. Thereafter, the mixture was stirred at 60 ° C. for 6 hours to synthesize a metal (iron) -organic framework (Fe-MOF). It was named Fe-MIL-88A.

Comparative Example 2 Preparation of Mn-MOF

40 mL of distilled water was added to the glass jar with a lid, and 0.99 g (5 mmol) of MnCl ₂ .4H ₂ O was added to dissolve it. Then sodium fumarate (1.6 g, 10 mmol) was dissolved in 40 mL of distilled water and slowly added. Thereafter, the mixture was stirred at 60 ° C. for 6 hours to synthesize a metal (manganese) -organic framework (Mn-MOF).

<Evaluation Example 1>

FeMn -MOF / FeMn -320, FeMn -400 / FeMn -600, FeMn -800 Structure and Properties Analysis

Synthesis of manganese maghemite and hematite and doping of manganese in Preparation Examples and Examples 1 to 4 were carried out using Fourier Transform Infrared (FT-IR) and Energy Dispersive Spectroscopy (EDS). ).

In addition, the crystal form and crystal size of the prepared material was analyzed by using powder X-ray diffraction (XRD) analysis.

High-resolution Transmission Electron Microscopy (HR-TEM), Scanning Transmission Electron Microscopy (STEM), and Field-Emission Scanning Electron Microscopy (FE-SEM) The organic framework and the shape and particle size of manganese maghemite and hematite were analyzed.

In addition, the specific surface area of the material was confirmed by Brunauer-Emmett-Teller (BET) method through nitrogen adsorption and desorption curve analysis, and the magnetic properties of the material were measured using a Vibrating Sample Magnetometer (VSM).

(1) Field emission scanning microscope (FE-SEM) analysis

The macrostructure of the synthesized manganese / iron binary metal-organic framework can be observed. It was confirmed from the images of FIGS. 2 (a) to 2 (c) that diamond particles having a size of about 200 to 300 nm were produced.

(2) Fourier Transform Infrared (FT-IR)

Using FT-IR analysis, it can be confirmed that manganese / iron dissimilar metal coordination compounds were formed. As will be confirmed from Figure 3, the asymmetric vibration mode of a symmetric carboxylic acid groups of the sodium fumarate molecules used as a ligand, represented at 1396 and 1603 cm ^-1 to go to the iron and manganese ions react with 1380 and 1594 cm ^-1 through It can be seen that the carboxyl group is combined with the metal ion.

(3) Powder X-ray diffraction (XRD)

X-ray diffraction analysis showed that the binary metal-organic framework was in an amorphous state and the metal oxide produced through sintering formed an oxidative base crystal structure. It can be seen from Figure 4 (a) that the iron / manganese metal-organic framework (FeMn-MOF) does not have a lot of crystallinity, and the crystal structure after sintering at 320 ℃ through Figure 4 (b) can be confirmed The coincidence of the major peaks of hemite can be seen to form a maghemite crystal structure, one of the iron oxide structures. It can be seen from FIG. 4 (d) that the peaks of (104) and (110) appear at 33.18 degrees and 35.3 degrees after sintering at 800 ° C., and coincide with the hematite crystal structure of iron oxide.

(4) thermogravimetric analysis (TGA)

TGA was performed in air on the FeMn-MOF obtained in the preparation example. It was confirmed from the TGA curve of FeMn-MOF shown in FIG. 5 that water was removed below 100 ° C. and pyrolyzed organic building blocks at temperatures above 440 ° C. in a two step process.

(5) X-ray photoelectron spectroscopy (XPS)

FeMn-MOF prepared by X-ray photoelectron spectroscopy (Preparation Example), Fe-MOF (Comparative Example 1), Mn-MOF (Comparative Example 2) and maghemite prepared by introducing manganese prepared (Example 1) And 2) and hematite (Examples 3 and 4). When the manganese was analyzed, it was confirmed that unlike the MOF (Comparative Example 2) in which only manganese was introduced, the manganese was reduced in the MOF (Preparation Example) in which iron and manganese were simultaneously introduced. It was confirmed that the peaks of manganese bivalent corresponding to 640.47 eV and manganese trivalent corresponding to 642.13 eV existed in the structure. When the peak corresponding to iron was analyzed, a reduced iron divalent peak was observed at 709.01 eV in the case of MOF (preparation example) introduced simultaneously with iron and manganese, unlike Fe-MOF of Comparative Example 1. After sintering, it was confirmed that the iron trivalent value of 710.7 eV was superior as the sintering temperature was increased in the maghemite and hematite structures of Examples 1 to 4.

(6) Transmission electron microscope (TEM) analysis

In order to observe small particles which are hard to observe in FE-SEM, particles produced after sintering of binary metal-organic framework were observed using TEM. 7 (a), it was confirmed that very small manganese maghemite particles having a size of about 10 nm were produced. 7 (b), it was confirmed that after sintering at 800 ° C., manganese hematite particles having a size of about 200 nm larger than that of manganese maghemite were produced.

(7) Nitrogen (N ₂ ) adsorption / desorption analysis

In order to confirm the specific surface area of manganese maghemite and hematite, nitrogen adsorption / desorption analysis was performed and the specific surface area was measured using the BET method. The results, Fig. 8 (a) to the case of manganese Marg H. boehmite from Fig. 8 (d) each of 62.0993 m ² /g,45.1486m ² for manganese hematite each 15.8991m ² /g,4.0526m measured by the ² / g It became.

(8) Vibrating Sample Magnetometer (VSM)

The magnetic properties of the prepared manganese maghemite and hematite were measured. 9 (a) and 9 (b), it was analyzed that the magnetic properties of 36 emu / g in the case of manganese maghemite and about 2.9 emu / g in the case of manganese hematite, and all show the superparamagnetic properties. .

(9) Energy Dispersive Spectroscopy (EDS)

To determine whether manganese ions were introduced into the maghemite and hematite structures, they were analyzed by energy dispersive spectral mapping. Particles with maghemite and hematite structures obtained through sintering through images of scanning transmission electron microscopy (STEM) and energy dispersive spectroscopy (EDS) of FIGS. 10 (a)-(d) and (e)-(h) It was observed that manganese was introduced.

(10) Nitrogen oxide reduction evaluation

Manganese-doped maghemite and hematite prepared in Examples 1 to 4 were evaluated for the ability to reduce nitrogen oxides using ammonia as the reducing agent. [NO] = [NH ₃ ] = 400ppm, 3vol% O ₂ and N ₂ were injected into the moving gas and the total gas flow was 1,000 mL / min and the space velocity was 30,000 h-1. FeMn-320) showed more than 80% catalytic activity from 150 ℃ to 300 ℃ and the highest performance of 97% at 250 ℃. As the sintering temperature increased, the catalytic performance decreased with temperature, and all of the materials showed the best performance at 250 ℃.

<Evaluation Example 2>

The reduction catalyst characteristics of nitrogen oxides were evaluated using the prepared manganese doped iron oxide catalyst.

The experimental conditions were [NO] = [NH ₃ ] = 400ppm, 3vol% O ₂ and N ₂ as a moving gas, the total gas flow was 1,000 mL / min, and the space velocity was 30,000 h ^-1 . The gas concentration was measured using a Test 350k analyzer, and the results are shown in FIG. 11.

Claims (8)

(S1) preparing an aqueous metal ion solution containing iron and manganese ions;
(S2) adding an organic compound to the aqueous metal ion solution;
(S3) forming a manganese / ferrous metal-organic framework (FeMn-MOF); And
(S4) pyrolysing the formed manganese / iron metal-organic framework (FeMn-MOF) to obtain maghemite iron oxide nanoparticles or manganese hematite iron oxide nanoparticles;
Manganese magehite-based iron oxide nanoparticles or manganese hematite-based iron oxide nanoparticles manufacturing method comprising a.
The method of claim 1,
All the steps of the manufacturing method is characterized in that carried out under an oxygen atmosphere, an atmospheric atmosphere or an atmosphere containing oxygen.
The method of claim 1,
Metal ion in the aqueous solution is to be included in a concentration of 0.1 mol / liter to 1.0 mol / liter, manufacturing method.
The method of claim 1,
Manganese ion concentration and iron ion concentration in the aqueous solution is the same, manufacturing method.
The method of claim 1,
The organic compound is a manufacturing method comprising an organic acid.
The method of claim 1,
The organic compound is prepared in the same amount as the concentration of the total metal ions contained in the aqueous solution.
The method of claim 1,
The sintering is carried out in the temperature range of 320 ℃ to 400 ℃, the final product obtained is characterized in that the manganese maghemite-based iron oxide nanoparticles.
The method of claim 1,
The sintering is carried out in the temperature range of 600 ℃ to 800 ℃, the final product obtained is characterized in that the manganese hematite iron oxide nanoparticles.

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