KR100620885B1 - Method for preparing cuprous oxide in nanoscale cubic form and cuprous oxide in nanoscale cubic form prepared by the same - Google Patents

Abstract

The present invention relates to a method for producing cuprous oxide (Cu ₂ O) in the form of nanoscale cubes and to a cuprous oxide in the form of nanosized cubes produced by the present invention, and more specifically, to a copper (Cu) metal of nanoscale By dispersing the powder in water and precipitating while oxidizing, the present invention relates to a method for producing a cuprous nitrous oxide having a nano-sized cube, and to a nano-sized cube-shaped cuprous oxide prepared thereby. The method for producing cuprous oxide of the present invention is low in energy consumption and simple to process, which is economical and suitable for mass production.

Nano size, cube shape, cuprous oxide

Description

TECHNICAL FIELD OF PREPARING CUPROUS OXIDE IN NANOSCALE CUBIC FORM AND CUPROUS OXIDE IN NANOSCALE CUBIC FORM PREPARED BY THE SAME}

1 is a flow chart of a method for producing cuprous oxide (Cu ₂ O) powder in the form of a nano-sized cube according to the present invention.

Figure 2 is a transmission electron microscope (Transmission Electron Microscope) of the nano-sized cube-shaped cuprous oxide (Cu ₂ O) powder prepared in Example 1 of the present invention.

The present invention relates to a method for producing cuprous oxide (Cu ₂ O) in the form of nanoscale cubes and to a cuprous oxide in the form of nanosized cubes produced by the present invention, and more specifically, to a copper (Cu) metal of nanoscale By dispersing the powder in water and precipitating while oxidizing, the present invention relates to a method for producing a cuprous nitrous oxide having a nano-sized cube, and to a nano-sized cube-shaped cuprous oxide prepared thereby. The method for producing cuprous oxide of the present invention is low in energy consumption and simple to process, which is economical and suitable for mass production.

In general, copper nitrous oxide is used in rectifier filters using ionization characteristics together with copper, a transition metal, as a P-type semiconductor, and is used in pigments for special functions such as photovoltaic materials and corrosion protection by playing an electron emission role in photovoltaic cells. It is also used as a negative electrode for solar energy conversion catalysts and lithium ion batteries.

In the case of copper oxide (CuO) in the manufacturing method of copper oxide, since it can manufacture by heating copper of metal in air, the manufacturing method is very simple. On the other hand, in the case of cuprous oxide, it is prepared by adding hydrazine to an aqueous solution of copper acetate (II), or by adding glucose to a Fehling's solution and heating, or using copper hydroxide (Cu (OH) ₂ ). It is common to manufacture by chemical reaction.

However, the conventional copper nitrite manufacturing methods as described above are not suitable for mass production process due to the high production cost and complicated process, and easy to prepare nitrous oxide powder having a size of micron or larger, but nano-size oxidization There is a problem in the production of copper powder, it does not meet the effects such as the increase of the specific surface area or the increase of mechanical properties due to the manufacture of the particles to the nano-size.

On the other hand, recently, methods for manufacturing or using powders of metals in nano-size have been studied. This means that when the metals become nano-sized powders, not only the mechanical properties such as hardness, strength, and abrasion resistance are improved, but the coefficient of thermal expansion is very high. This is because it is known to have improved physical properties compared to existing materials in chemical and electromagnetic properties, such as larger and lower activation energy.

In addition, when the cuprous oxide is manufactured in the shape of a cube having a particle size of several tens to several tens of nanometers, the mechanical properties are improved because the particles are fine, and since the inside of the cube is empty, a higher application value can be obtained using the same. Can be.

Korean Patent Laid-Open Publication No. 2003-0035206 discloses a chemical synthesis method of various types of nano-sized inorganic crystals, including cubes, wherein a single precursor is dissolved in a suitable organic solvent, and the solution is After the injection into the stabilizer of the pyrolysis at a predetermined reaction temperature to have a specific crystal structure, in this way the precursor of the selected nanocrystals of the crystal structure is injected at a predetermined concentration, and reacted for a predetermined time, the size and shape of the nanocrystals Can be adjusted. However, this method is not universally applicable to various metals and inorganic materials, and the type and amount of organic solvents, the type and amount of stabilizers, reaction temperature, injection concentration of nanocrystalline precursors, and reaction time according to numerous target inorganic materials. There are disadvantages, such as different one by one, many kinds of reagents used, complicated process.

As such, in the case of conventional copper nitrite manufacturing methods, it is very difficult to control the shape of the nano-size copper oxide particles in the form of cubes, and the conventional nano-size inorganic crystal synthesis method is difficult due to various problems as described above. Since it is difficult to actually apply to the production of cuprous oxide in the size of the cube, there is a need to develop a method for producing copper oxide in the form of nano-sized cubes simply and economically and effectively.

The present invention is to solve the problems of the prior art as described above, an object of the present invention, by producing a cuprous oxide particles in the form of nano-sized cubes to exhibit very excellent catalytic activity, useful for high-performance filters, photovoltaic materials, etc. In addition to being able to be used, low energy consumption is economical, and the manufacturing process is simple to provide a method for producing a nano-sized cube-shaped cuprous oxide suitable for mass production and the nano-sized cube-shaped cuprous oxide produced thereby.

In order to achieve the above object, according to the present invention, (1) adding a nano-sized copper powder having a particle size of 1 ~ 500nm in water and dispersing; (2) producing and precipitating cuprous oxide by leaving the dispersion at a temperature of 30-70 ° C .; And (3) filtering and drying the resultant precipitate of step (2), thereby providing a method for producing copper oxide in the form of nano-sized cubes.

The nano-sized copper powder used in the present invention may be obtained through a nano-sized metal powder manufacturing method such as an electroexplosion method, a dry smelting method, a flotation gas condensation method, and the like. It is preferable to use the copper powder.

For the production of nano-sized copper powder by the flotation gas condensation method or the electro-explosion method, the flotation gas condensation method and the Republic of Korea Patent Publication No. 10-2003-0093636 already filed by the present inventors The electroexplosion method described in -29606 may be used, and other conventional methods for preparing nano-sized copper powder may be used as is or appropriately modified.

By the flotation gas condensation method or the electric explosion method, not only the nano-sized copper powder can be easily produced in large quantities, but also because the manufactured powder has a size of about 30 nm or less, It has a specific surface area (about 17 m 2 / g). The prepared copper powder may be used by applying a passivation film having a thickness of 1 to 2 nm on its surface, so that copper having high oxidizing power can be handled in air.

The nano-sized copper powder used in the present invention has a particle size of 1 to 500 nm, preferably 10 to 100 nm, but when the particle size is less than 1 nm, workability and productivity are lowered. The size of the copper is too large, the work time is long. In the case of general commercial copper powder has a particle size of about 50㎛, when using the copper powder of this size in the manufacturing method according to the present invention, the time required for the completion of the precipitation is about 3 to 4 days, a relatively long time It takes

In the production method of the present invention, the water (H ₂ O) used in the step (1) is a medium for dispersing the nano-sized copper powder, and in the subsequent oxidation reaction becomes a reactant, the final nitrous oxide Since the mother liquid in which copper crystal grains grow, it is necessary to suppress the containment of the impurity which affects crystal growth as much as possible. Therefore, it is preferable to use purified water as the water used in the step (1). There is no particular limitation on the level of purification, and within the range in which the nano-sized cube-shaped cuprous oxide crystal grains can be grown, one skilled in the art can easily select according to the conditions of the production equipment. The temperature of the water used in step (1) is not particularly limited, but about 40 ° C. is appropriate in consideration of the temperature conditions of the subsequent oxidation reaction.

There is no particular limitation as to the method of dispersion performed in the step (1), but in consideration of the fact that the nano-sized copper powder should be uniformly dispersed, and the incorporation of impurities into the dispersion medium as described above. In view, a dispersion method using ultrasonication is preferred.

In the above step (1), the amount of the nano-sized copper powder dispersed in water can be dispersed in water and consequently within the range in which the nano-sized cube-shaped cuprous oxide crystal particles of the present invention can be obtained. There is no limitation, but considering the efficiency and economic efficiency of the production process, the copper powder is preferably added in an amount of 0.1 to 1 part by weight, more preferably 0.2 to 0.4 part by weight based on 100 parts by weight of water. When the amount of the copper powder dispersed in 100 parts by weight of water is less than 0.1 part by weight, the amount of copper nitrite produced in one reaction is not sufficient, which is inefficient, and when the amount of the copper powder exceeds 1 part by weight, the following formula ( In the subsequent oxidation reactions such as 1), the amount of unreacted copper is not economical because the amount of unreacted copper becomes too large, and the unreacted copper is recovered from the precipitate obtained in step (2) and reused. This is because there is a disadvantage in that the process is required separately.

2Cu + H ₂ O-> Cu ₂ O + H ₂ ... … Formula (1)

In the production method of the present invention, in the step (2), by maintaining the temperature of 30 ~ 70 ℃ in the presence of the catalyst of the oxidation reaction in the dispersion obtained as a result of the step (1), The reaction produces and precipitates cuprous oxide.

In step (2), a catalyst may be used to further promote the oxidation reaction. The type and amount of the catalyst used is not particularly limited as long as it is a type and amount capable of performing a catalytic function in the oxidation reaction, and an acid catalyst such as acetic acid can be used, and the amount is about 0.1 to 0.8 ml with respect to 1000 ml of the dispersion. The range of is suitable.

In the step (2), the temperature of the dispersion liquid during the oxidation reaction and precipitation is maintained at 30 to 70 ° C, preferably at 30 to 50 ° C. When the oxidation reaction and precipitation is carried out at 30 ℃ or less, the reaction rate is too slow to reduce the production efficiency, and even if it exceeds 70 ℃ no further reaction rate is increased, the reaction is carried out at temperature conditions exceeding 70 ℃ Doing is inefficient in terms of energy.

In the step (2), if the dispersion is left while maintaining the temperature of 30 ~ 70 ℃, the red cuprous oxide precipitate is formed as the leaving time elapses. The leaving time is slightly different depending on the use of the catalyst, the type and amount of the catalyst used and the actual production conditions, but if it is too short, the amount of precipitation of copper oxide becomes insufficient, and if it is too long, the work efficiency and production efficiency are lowered. Generally, it is preferable to leave for 1 to 40 hours.

The formation of cuprous oxide precipitates is not formed immediately with the initiation of the reaction, but only after some time of incubation, which means that there is a relatively high energy barrier to the oxidation reaction. Therefore, by lowering the energy barrier by using a catalyst, or by supplying energy to the reactants to overcome the energy barrier by increasing the reaction temperature, it is possible to reduce the waiting time required to complete the precipitation step. . However, an object of the present invention is the production of cuprous oxide powder having a nano-sized cube form, the excessive increase in the reaction and precipitation rate may lead to irregular growth of the cuprous oxide particles crystals, rather it may make it difficult to achieve the object of the invention. Therefore, in the modification of the present invention, whether or not the catalyst is used in step (2), the type and amount of the catalyst used and the reaction temperature achieve the object of the present invention to prepare a cuprous oxide powder having a nano-sized cube shape. It should be done to the extent possible.

In the production method of the present invention, in step (3), the resultant step of step (2) is filtered and dried to obtain a cuprous oxide powder having a nano-sized cube form. The filtration is generally performed using a filtration medium having pores of about 0.1 μm in view of the filtration efficiency, and the filtered product is washed with purified water or the like and then dried in an oven at about 40 ° C. to obtain cuprous oxide powder.

The copper oxide in the form of a nano-sized cube according to the present invention obtained as described above is a cubic system having a crystal structure of a ₀ = 4.264 kPa, and has an average particle diameter of 2 to 50 nm, and its particle shape is a cube.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited by these examples.

Example 1

To 1000 g of distilled water at 40 ° C. contained in a predetermined reaction container, 1 g of spherical nano-sized copper powder prepared by gas condensation and having a BET specific surface area of 17 m 2 / g was added thereto, followed by dispersing by sonication for 10 minutes. ((Stage 1). Next, 0.4 ml of acetic acid was added to the dispersion as a catalyst for the oxidation reaction, and left for 6 hours while maintaining the temperature of the dispersion at 40 ° C. to precipitate copper nitrite ((2)). The precipitate obtained above was collected, filtered using a filter paper having pores of 0.1 μm, washed with purified water, and dried in an oven at 40 ° C. for 12 hours to obtain a cuprous oxide powder having a nano-sized cube. Step 3).

The total mass after drying of the obtained cuprous oxide was measured and shown in Table 1, and an X-ray diffractometer (Rigaku D / Max III, manufactured by Rigaku, Japan; Ni-filter CuKα light source) was used. The relative contents of copper (Cu) and cuprous oxide (Cu ₂ O) contained in the cuprous oxide powder were measured, respectively, and the results are shown in Table 1. In addition, the obtained cuprous oxide powder was observed with a Transmission Electron Microscope (JEM2000, manufactured by JEOL, Inc .; acceleration voltage 200kV), and a photograph thereof is shown in FIG. 2. The observation magnification was 300,000 times. As a result, the cuprous oxide powder particles were in the form of cubes, and the average length of the edge was about 20 nm.

Example 2

A cuprous oxide powder was produced in the same manner as in Example 1 except that the amount of copper powder added to 1000 g of distilled water was 2 g. The total mass and the relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the copper nitrous oxide powder after drying was measured in the same manner as in Example 1, and the results are shown in Table 1. .

Example 3

A cuprous oxide powder was produced in the same manner as in Example 1, except that the amount of copper powder added to 1000 g of distilled water was 3 g. The total mass and the relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the copper nitrous oxide powder after drying was measured in the same manner as in Example 1, and the results are shown in Table 1. .

Example 4

A cuprous oxide powder was prepared in the same manner as in Example 1, except that the amount of copper powder added to 1000 g of distilled water was 4 g. The total mass and the relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the copper nitrous oxide powder after drying was measured in the same manner as in Example 1, and the results are shown in Table 1. .

Example 5

A cuprous oxide powder was produced in the same manner as in Example 1 except that the amount of copper powder added to 1000 g of distilled water was 6 g. The total mass and the relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the copper nitrous oxide powder after drying was measured in the same manner as in Example 1, and the results are shown in Table 1. It was.

Example 6

A cuprous oxide powder was produced in the same manner as in Example 1, except that the amount of copper powder added to 1000 g of distilled water was 10 g. The total mass and the relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the copper nitrous oxide powder after drying was measured in the same manner as in Example 1, and the results are shown in Table 1. .

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Amount of Nanosize Copper Powder per 1000g of Water (g) One 2 3 4 6 10 Total mass (g) after drying of the obtained cuprous oxide powder 0.8 2.3 4.1 5.5 7 11.5 Cu content in cuprous oxide powder (%) 0 0 0 0 24 41 Cu ₂ O content in cuprous oxide powder (%) 100 100 100 100 76 59

Referring to Table 1, in the case of Examples 1 to 4 in which 1 to 4 g of the nano-sized copper powder was added to 1000 g of distilled water, all of the reactants Cu were oxidized to Cu ₂ O, while 6 g and 10 g of the nano copper powder were added, respectively. In Examples 5 and 6, a significant amount of unreacted copper powder remained in the obtained cuprous oxide powder, and it was found that the reaction and precipitation time were more necessary than those of Examples 1 to 4 in order to complete the reaction. In addition, in the case of Example 1, since the amount of the nano-sized copper powder as a reactant was relatively small (1 g), the amount lost during the collection process of the prepared cuprous oxide powder was relatively higher than that of the other examples.

Comparative Example 1

A cuprous oxide powder was prepared in the same manner as in Example 4, except that the temperature of the dispersion was maintained at 20 ° C. in step (2) for the reaction and precipitation. The relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the prepared cuprous oxide powder was measured in the same manner as in Example 4, the results are shown in Table 2.

Example 7

A cuprous oxide powder was prepared in the same manner as in Example 4, except that the temperature of the dispersion was maintained at 30 ° C. in step (2). The relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the prepared cuprous oxide powder was measured in the same manner as in Example 4, the results are shown in Table 2.

Example 8

A cuprous oxide powder was prepared in the same manner as in Example 4 except that the temperature of the dispersion was maintained at 50 ° C. in step (2). The relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the prepared cuprous oxide powder was measured in the same manner as in Example 4, the results are shown in Table 2.

Example 9

A cuprous oxide powder was prepared in the same manner as in Example 4 except that the temperature of the dispersion was maintained at 70 ° C. in step (2). The relative content of copper (Cu) and copper nitrous oxide (Cu ₂ O) contained in the prepared cuprous oxide powder was measured in the same manner as in Example 4, the results are shown in Table 2.

Comparative Example 1 Example 7 Example 8 Example 9 Temperature of Dispersion (℃) 20 30 50 70 Cu content in cuprous oxide powder (%) 56 42 39 37 Cu ₂ O content in cuprous oxide powder (%) 44 58 61 63

Looking at Table 2, in Examples 7 to 9 where the temperature of the dispersion was maintained at 30 to 70 ° C. in step (2), copper (Cu) and copper nitrous oxide (Cu ₂ O) included in the manufactured cuprous oxide powder. While the relative content of is relatively constant, in Comparative Example 1 in which the temperature of the dispersion was maintained at 20 ° C., it can be seen that very much unreacted copper (Cu) powder remains in the prepared cuprous oxide powder.

As described above, according to the method for producing a nano-sized cube-type cuprous oxide according to the present invention, it shows a very excellent catalytic activity and can be useful in the nano-sized cube-type which can be usefully used for hydrogen peroxide separation catalyst, calorimetry sensor, high-performance filter Copper nitrous oxide can be manufactured economically and simply with high production efficiency.

Claims (5)

(1) adding and dispersing nano-sized copper powder having a particle size of 1-500 nm to water; (2) adding an oxidation reaction catalyst to the dispersion, and generating and precipitated cuprous oxide by leaving it at a temperature of 30 ° C. to 70 ° C .; And (3) The method for producing cuprous oxide in the form of nano-sized cube characterized in that it comprises the step of filtering and drying the resultant precipitate of step (2). The method of claim 1, wherein in the step (1), 0.1 to 1 part by weight of the nano-sized copper powder is added to 100 parts by weight of water. The method of claim 1, wherein in step (2), the temperature of the dispersion is maintained at 30 to 50 ° C. delete A method according to any one of claims 1 to 3, characterized in that the crystal structure is a cubic system having a ₀ = 4.264 Å, has a particle diameter of 2 to 50 nm, and the particle shape is in the form of a cube. Cuprous oxide.

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