Cuprous oxide nanoparticles with high oxidation stability and method of menufacturign the same

Abstract

A copper(II) oxide nanoparticle with high oxidation stability and a method for manufacturing the same are disclosed. The copper(II) oxide nanoparticle of the present invention is a copper(II) oxide nanoparticle comprising copper(II) oxide (Cu2O), and the copper(II) oxide nanoparticle has a shape selected from the group consisting of a sphere, a hexahedron, and an octahedron. It has high crystallinity and excellent oxidation stability, excellent oxidation stability even after heat treatment, excellent antibacterial efficiency due to the surface crystal plane according to the shape of the copper(II) oxide nanoparticle, and maintains antibacterial properties even when exposed to a humid environment.

Description

Technology Field

[0001] The present invention relates to copper(I) oxide nanoparticles with high oxidation stability and a method for manufacturing the same. Background Technology

[0002] The antimicrobial properties of copper are widely known, and it is used as a key ingredient in various antimicrobial products. However, copper loses its inherent antimicrobial ability because it oxidizes easily. Copper oxides appear in forms such as cuprous oxide (Cu2O), cuprous oxide (CuO), and ternary oxide (Cu2O3). Generally, metallic copper exhibits excellent antimicrobial activity; in particular, cuprous oxide is known to display high antimicrobial activity by releasing more copper ions than cuprous oxide. However, cuprous oxide can also transform into cuprous oxide over time. Therefore, cuprous oxide, which has high oxidation stability, is expected to be widely utilized not only as an antimicrobial agent but also as an electrode and catalyst material.

[0003] Methods for manufacturing nano-sized copper oxide particles are classified into gas-phase and liquid-phase methods, and they can be synthesized using various techniques such as chemical vapor condensation, hydrothermal methods, sol-gel, precipitation, and spraying. However, most copper oxide particle manufacturing methods have limited applicability due to complex processes or difficulties in effectively controlling particle size.

[0004] Therefore, there is a need to develop copper particles that are easy to manufacture, highly economical, and have excellent thermal oxidation stability. Prior art literature

[0005] Korean Registered Patent No. 10-0692159 (March 2, 2007) The problem to be solved

[0006] The objective of the present invention is to provide copper(I) oxide nanoparticles with excellent oxidation stability and antibacterial properties by controlling the shape of the copper(I) oxide nanoparticles, and a method for manufacturing the same. means of solving the problem

[0007] According to one aspect of the present invention, a copper(I) oxide nanoparticle is provided, comprising copper(I) oxide (Cu2O), wherein the copper(I) oxide nanoparticle has a shape selected from the group consisting of a sphere, a hexahedron, and an octahedron.

[0008] In addition, the copper(II) oxide nanoparticles have a spherical shape, and the specific surface area of ​​the spherical copper(II) oxide nanoparticles is 30 to 50 m² 2 / g, preferably 35 to 40 m 2 It can be / g.

[0009] In addition, the crystal size of the spherical copper(I) oxide nanoparticles may be 3 to 8 nm, preferably 5 to 7 nm, and the ratio of (111) crystal face / (200) crystal face (facet) may be 2 to 5, preferably 3 to 4.

[0010] In addition, the copper(II) oxide nanoparticles have a cubic shape, and the specific surface area of ​​the cubic copper(II) oxide nanoparticles is 2 to 6 m² 2 / g, preferably 3 to 5 m 2 It can be / g.

[0011] In addition, the crystal size of the hexahedral-shaped copper(I) oxide nanoparticles may be 30 to 50 nm, preferably 35 to 40 nm, and the ratio of (110) crystal planes to (200) crystal planes may be 1.5 to 4, preferably 2 to 3.

[0012] In addition, the copper(II) oxide nanoparticles have an octahedral shape, and the surface area of ​​the octahedral copper(II) oxide nanoparticles is 2 to 9 m 2 / g, preferably 4 to 6 m 2 It can be / g.

[0013] In addition, the crystal size of the above octahedral-shaped copper(I) oxide nanoparticles may be 15 to 30 nm, preferably 20 to 25 nm, and the ratio of (110) crystal planes to (200) crystal planes may be 1 to 4, preferably 2.5 to 3.0.

[0014] In addition, the above-mentioned copper(I) oxide nanoparticles may be used as an antimicrobial material.

[0015] According to another aspect of the present invention, a method for producing copper(I) oxide nanoparticles is provided, comprising: (a) preparing a copper precursor solution containing a copper precursor; (b) preparing a reducing agent solution containing a reducing agent; (c) mixing the copper precursor solution and the reducing agent solution to prepare a mixed solution; and (d) reacting the mixed solution to produce copper(I) oxide (Cu2O) nanoparticles.

[0016] In addition, in step (a), the copper precursor may include one or more selected from the group consisting of Cu(NO3)2 hydrate, Cu(Ac)2 hydrate, and CuCl2 hydrate.

[0017] In addition, in step (b), the reducing agent may include one or more selected from the group consisting of hydrazine (N2H4), ascorbic acid (C6H8O6) and sodium borohydroxide (NaBH4).

[0018] In addition, the copper(I) oxide nanoparticles may have a shape selected from the group consisting of spheres, hexahedrons, and octahedrons.

[0019] In addition, the reducing agent may include hydrazine (N2H4), and the copper(I) oxide nanoparticles may have a spherical shape.

[0020] In addition, the copper precursor solution of step (a) may further contain a base, the reducing agent of step (b) may contain hydrazine (N2H4), and the copper(I) oxide nanoparticles may have an octahedral shape.

[0021] In addition, the copper precursor solution of step (a) may further contain a base, the reducing agent of step (b) may contain ascorbic acid (C6H8O6), and the copper(I) oxide nanoparticles may have a hexahedral shape.

[0022] In addition, the above base may include one or more selected from the group consisting of NaOH, KOH, and NH4OH.

[0023] In addition, the shape of the copper(I) oxide nanoparticles can be controlled by adjusting the type of the reducing agent.

[0024] In addition, in step (c), the mixing may be performed by stirring for 10 to 90 minutes. Effects of the invention

[0025] The present invention controls the shape of copper(I) oxide nanoparticles to achieve high crystallinity and excellent oxidation stability, and has the effect of maintaining excellent oxidation stability even after heat treatment.

[0026] In addition, the antibacterial efficiency is excellent due to the surface crystal planes according to the shape of the copper(II) oxide nanoparticles, and the antibacterial properties are maintained even when exposed to a humid environment. Brief explanation of the drawing

[0027] These drawings are for reference to explain exemplary embodiments of the present invention, and therefore, the technical concept of the present invention should not be interpreted as being limited to the attached drawings. FIG. 1 is a flowchart illustrating a method for preparing copper(II) oxide nanoparticles according to one embodiment of the present invention. FIG. 2 is a table showing the morphology and surface crystal planes of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention. FIG. 3 is a diagram showing the atomic arrangement of copper(I) oxide nanoparticles according to crystal planes according to Examples 1 to 3 of the present invention. Figure 4 is an SEM image of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention. Figure 5 is a TGA graph showing the heat-treated state of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention. FIG. 6a is an XRD graph showing the state of heat-treated copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention, and FIG. 6b is an XRD graph showing the state before and after heat-treated copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention, respectively. FIG. 7a is an XRD graph showing the state of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention before exposure to a humid environment, FIG. 7b is an XRD graph showing the state of copper(I) oxide nanoparticles according to Example 1 of the present invention after exposure to a humid environment for 1 to 8 weeks, FIG. 7c is an XRD graph showing the state of copper(I) oxide nanoparticles according to Example 2 of the present invention after exposure to a humid environment for 1 to 8 weeks, and FIG. 7d is an XRD graph showing the state of copper(I) oxide nanoparticles according to Example 3 of the present invention after exposure to a humid environment for 1 to 8 weeks. FIG. 8a is an XPS graph showing the state of copper(II) oxide nanoparticles according to Examples 1 to 3 of the present invention after being exposed to a humid environment for 4 weeks, FIG. 8b is an XPS graph showing the state of copper(II) oxide nanoparticles according to Example 1 of the present invention after being exposed to a humid environment for 4 weeks, FIG. 8c is an XPS graph showing the state of copper(II) oxide nanoparticles according to Example 2 of the present invention after being exposed to a humid environment for 4 weeks, and FIG. 8d is an XPS graph showing the state of copper(II) oxide nanoparticles according to Example 2 of the present invention after being exposed to a humid environment for 4 weeks. FIG. 9 is a graph showing the change in antibacterial activity of copper(I) oxide nanoparticle powder according to the exposure period by exposing copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention to a humid environment for 1 to 8 weeks. FIG. 10 is a graph showing the results of an antibacterial test before and after heat treatment of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention. Specific details for implementing the invention

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention.

[0029] However, the following description is not intended to limit the present invention to specific embodiments, and detailed descriptions of related prior art are omitted if it is determined that such detailed descriptions could obscure the essence of the present invention.

[0030] The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, terms such as “comprising” or “having” are intended to specify the presence of the features, numbers, steps, actions, components, or combinations thereof described in the specification, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, or combinations thereof.

[0031] Additionally, terms including ordinal numbers, such as "first," "second," etc., used below may be used to describe various components, but said components are not limited by said terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0032] Furthermore, when it is stated that a component is "formed" or "laminated" on another component, it should be understood that while it may be formed or laminated by being directly attached to the entire surface or one surface of the other component, there may also be other components present in between.

[0033] Hereinafter, copper(II) oxide nanoparticles with high oxidation stability and a method for manufacturing the same will be described in detail. However, this is presented as an example and is not intended to limit the present invention, and the present invention is defined only by the scope of the claims set forth below.

[0034] According to one aspect of the present invention, a copper(I) oxide nanoparticle is provided, comprising copper(I) oxide (Cu2O), wherein the copper(I) oxide nanoparticle has a shape selected from the group consisting of a sphere, a hexahedron, and an octahedron.

[0035] In addition, the copper(II) oxide nanoparticles have a spherical shape, and the specific surface area of ​​the spherical copper(II) oxide nanoparticles is 30 to 50 m² 2 / g, preferably 35 to 40 m 2 It can be / g. Here, the specific surface area of ​​the spherical cuprous oxide nanoparticles is 30 m² 2 If it is less than / g, the antibacterial activity may be low, so it is undesirable, and 50 m 2If it exceeds / g, oxidation stability may decrease, which is undesirable.

[0036] In addition, the crystal size of the spherical copper(I) oxide nanoparticles may be 3 to 8 nm, preferably 5 to 7 nm, and the ratio of (111) crystal face to (200) crystal face may be 2 to 5, preferably 3 to 4. Here, if the crystal size of the spherical copper(I) oxide nanoparticles is less than 3 nm, the crystallinity is low and there are many crystal boundaries, so the possibility of oxidation is high and is undesirable; if the ratio of (111) crystal face to (200) crystal face is less than 2, the antibacterial activity may be low and is undesirable; and if it exceeds 5, the stability of the (111) crystal face is low and may oxidize and is undesirable.

[0037] In addition, the copper(II) oxide nanoparticles have a cubic shape, and the specific surface area of ​​the cubic copper(II) oxide nanoparticles is 2 to 6 m² 2 / g, preferably 3 to 5 m 2 It can be / g. Here, the specific surface area of ​​the hexahedral-shaped cuprous oxide nanoparticles is 2 m 2 If it is less than / g, the antibacterial activity may be low, so it is undesirable, and 6 m 2 If it exceeds / g, oxidation stability may decrease, which is undesirable.

[0038] In addition, the crystal size of the hexahedral-shaped copper(I) oxide nanoparticles may be 20 to 50 nm, preferably 35 to 40 nm, and the ratio of (111) crystal facets to (200) crystal facets may be 1.5 to 4, preferably 2 to 3. Here, if the crystal size of the hexahedral-shaped copper(I) oxide nanoparticles is less than 20 nm, there are many crystal boundaries, so there is a high possibility of oxidation, which is undesirable; if the ratio of (111) crystal facets to (200) crystal facets is less than 1.5, there are few (111) crystal facets, so antibacterial activity may be reduced, which is undesirable; and if it exceeds 4, the stability of the (111) crystal facets is low, so there is a high possibility of oxidation, which is undesirable.

[0039] In addition, the copper(II) oxide nanoparticles have an octahedral shape, and the surface area of ​​the octahedral copper(II) oxide nanoparticles is 2 to 9 m 2 / g, preferably 4 to 6 m 2 It can be / g. Here, the specific surface area of ​​the octahedral-shaped cuprous oxide nanoparticles is 2 m 2 If it is less than / g, the antibacterial activity may be low, so it is undesirable, and 9 m 2 If it exceeds / g, oxidation stability may decrease, which is undesirable.

[0040] In addition, the crystal size of the above octahedral-shaped copper(I) oxide nanoparticles may be 15 to 30 nm, preferably 20 to 25 nm, and the ratio of (110) crystal face to (200) crystal face may be 1 to 4, preferably 2.5 to 3.0. Here, if the crystal size of the above octahedral-shaped copper(I) oxide nanoparticles is less than 15 nm, the crystallinity is low and there are many crystal boundaries, so the possibility of oxidation is high, which is undesirable; if the ratio of (111) crystal face to (200) crystal face is less than 1, the antibacterial activity may be low, which is undesirable; and if it exceeds 4, the stability of the (111) crystal face is low, so oxidation may occur, which is undesirable.

[0041] In addition, the above-mentioned copper(I) oxide nanoparticles may be used as an antimicrobial material.

[0042] According to another aspect of the present invention, a method for producing copper(I) oxide nanoparticles is provided, comprising: (a) preparing a copper precursor solution containing a copper precursor; (b) preparing a reducing agent solution containing a reducing agent; (c) mixing the copper precursor solution and the reducing agent solution to prepare a mixed solution; and (d) reacting the mixed solution to produce copper(I) oxide (Cu2O) nanoparticles.

[0043] In addition, in step (a), the copper precursor may include one or more selected from the group consisting of Cu(NO3)2 hydrate, Cu(Ac)2 hydrate, and CuCl2 hydrate.

[0044] In addition, in step (b), the reducing agent may include one or more selected from the group consisting of hydrazine (N2H4), ascorbic acid (C6H8O6) and sodium borohydroxide (NaBH4).

[0045] In addition, the copper(I) oxide nanoparticles may have a shape selected from the group consisting of spheres, hexahedrons, and octahedrons.

[0046] In addition, the reducing agent may include hydrazine (N2H4), and the copper(I) oxide nanoparticles may have a spherical shape.

[0047] In addition, the copper precursor solution of step (a) may further contain a base, the reducing agent of step (b) may contain hydrazine (N2H4), and the copper(I) oxide nanoparticles may have an octahedral shape.

[0048] In addition, the copper precursor solution of step (a) may further contain a base, the reducing agent of step (b) may contain ascorbic acid (C6H8O6), and the copper(I) oxide nanoparticles may have a hexahedral shape.

[0049] In addition, the above base may include one or more selected from the group consisting of NaOH, KOH, and NH4OH.

[0050] In addition, the shape of the copper(I) oxide nanoparticles can be controlled by adjusting the type of the reducing agent.

[0051] In addition, in step (c), the mixing may be performed by stirring for 10 to 90 minutes. Here, if the mixing is performed for less than 10 minutes, it is undesirable because the reduction proceeds less and CuO may be formed, and if it is performed for more than 90 minutes, it is undesirable because the reduction proceeds more and Cu may be formed.

[0052] [Example]

[0053] The present invention will be explained in more detail below with reference to examples. However, this is for illustrative purposes only and does not limit the scope of the present invention.

[0054] Example: Preparation of cuprous oxide nanoparticles by form

[0055] Example 1: Preparation of spherical cuprous oxide nanoparticles

[0056] FIG. 1 is a flowchart illustrating a method for preparing copper(I) oxide nanoparticles according to one embodiment of the present invention. Referring to FIG. 1, 1.8 L of a copper precursor solution, 0.025 M Cu(NO3)2·3H2O, was prepared by mixing a copper precursor, Cu(NO3)2·3H2O, with water, which is a solvent. 4.7 ml of a reducing agent solution, 17.66 M N2H4·xH2O, was prepared by mixing a reducing agent, hydrazine (N2H4), with water, which is a solvent. The copper precursor solution and the reducing agent solution were mixed together and stirred for 60 minutes, and then vacuum filtered and dried to prepare spherical copper(I) oxide nanoparticles.

[0057] Example 2: Preparation of Octahedronic Cuprous Oxide Nanoparticles

[0058] 21.8 L of a 0.025 M Cu(NO3)2·3H2O copper precursor solution was prepared by mixing the copper precursor Cu(NO3)2·3H2O with water as a solvent. 210 ml of a 1 M NaOH base was added to the copper precursor solution and stirred for 15 minutes to prepare a mixture containing the copper precursor and the base. Subsequently, hydrazine (N2H4) as a reducing agent was mixed with water as a solvent to prepare a 17.66 M N2H4·xH2O reducing agent solution of 4.7 ml. The mixture containing the copper precursor and the base and the reducing agent solution were mixed together and stirred for 60 minutes, followed by vacuum filtration and drying to prepare octahedral cuprous oxide nanoparticles.

[0059] Example 3: Preparation of Cube-shaped Cuprous Oxide Nanoparticles

[0060] 21.8 L of 0.025 M Cu(NO3)2·3H2O, a copper precursor, was prepared by mixing it with water, a solvent. 210 ml of 1.5 M NaOH, a base, was added to the copper precursor solution and stirred for 15 minutes to prepare a mixture containing the copper precursor and the base. Subsequently, 170 ml of 0.33 M ascorbic acid (C6H8O6), a reducing agent, was added to the mixture containing the copper precursor and the base and stirred for 60 minutes. Afterward, hexahedral cuprous oxide nanoparticles were prepared by vacuum filtration and drying.

[0061] [Test Example]

[0062] Test Example 1: Comparison of Surface Crystal Planes by Morphology

[0063] FIG. 2 is a table showing the shape and surface crystal plane of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention, and FIG. 3 is a diagram showing the atomic arrangement of copper(I) oxide nanoparticles according to the crystal plane of Examples 1 to 3 of the present invention. Referring to FIG. 2 and FIG. 3, it was confirmed that the surface crystal plane differs depending on the shape of the copper(I) oxide nanoparticles, and that the arrangement of Cu atoms and O atoms present on the surface differs depending on the crystal plane. The octahedral copper(I) oxide nanoparticles according to Example 2 of the present invention have a (111) crystal plane, and the (111) crystal plane has Cu atoms and O atoms alternately present, and has the characteristic of easy atomic bonding and good oxidation due to the presence of dangling bonds. Meanwhile, the hexahedral copper(I) oxide nanoparticles according to Example 3 of the present invention have a (100) crystal plane, and the (100) crystal plane exists as an O atomic layer.

[0064] Therefore, it was confirmed that the antibacterial efficiency was best in the octahedral copper(II) oxide nanoparticles according to Example 2, followed by the hexahedral ones according to Example 3, and then the spherical ones according to Example 1.

[0065] Test Example 2: SEM Analysis

[0066] FIG. 4 is an SEM image of cuprous oxide nanoparticles according to Examples 1 to 3 of the present invention, and Table 1 below shows the surface area of ​​cuprous oxide nanoparticles according to Examples 1 to 3 of the present invention. Referring to FIG. 4 and Table 1, the surface area of ​​the spherical cuprous oxide nanoparticles according to Example 1 of the present invention is 37.5483 m² 2 / g, and the surface area of ​​the octahedral cuprous oxide nanoparticles according to Example 2 is 5.2190 m² 2 / g, and the surface area of ​​the hexahedral cuprous oxide nanoparticles according to Example 3 is 4.3089 m² 2 It appeared as / g.

[0067] division Example 1 Example 2 Example 3 form Spherical Cu2O Octahedral Cu2O Cubic Cu2O Surface Area (m 2 / g) 37.5483 5.2190 4.3089

[0068] Test Example 3: TGA Analysis

[0069] FIG. 5 is a TGA graph showing the heat-treated state of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention, and Table 2 below is a table showing the data of the TGA graph showing the heat-treated state of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention.

[0070] Referring to Figure 5 and Table 2, it was found that the weight increase of Example 1 started at 175 ℃, while the weight increase of the remaining Examples 2 to 3 occurred at 198 ℃. The weight increase is due to oxygen atoms attaching as oxidation occurs. Therefore, when comparing the oxidation rates of Examples 1 to 3 based on the slope of the weight increase section, it was found that Example 3 had the lowest oxidation rate.

[0071] division form Weight gain start Temp. (℃) Slope of weight gain section Final weight percent (%) Example 1 Spherical Cu2O 175 28.8 103.6 % Example 2 Octahedral Cu2O 198 9.54 101.8 % Example 3 Cubic Cu2O 198 4.14 100.25%

[0072] In Table 2 above, the Slope of weight gain section is a value obtained by calculating the maximum value after the first derivative of the TGA graph.

[0073] Test Example 4: XRD Analysis

[0074] FIG. 6a is an XRD graph showing the heat-treated state of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention, and FIG. 6b is an XRD graph showing the heat-treated state of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention. Referring to FIG. 6a and FIG. 6b, it was found that the crystallinity was highest in the hexahedral copper(I) oxide nanoparticles according to Example 3 of the present invention, followed by the octahedral copper(I) oxide nanoparticles according to Example 2, and then the spherical copper(I) oxide nanoparticles according to Example 1. (100) It was found that the hexahedral copper(I) oxide nanoparticles having crystal faces maintained their crystalline phase even after heat treatment. In addition, it was found that the thermal oxidation stability was also highest in the hexahedral copper(I) oxide nanoparticles according to Example 3 of the present invention, followed by the octahedral copper(I) oxide nanoparticles according to Example 2, and then the spherical copper(I) oxide nanoparticles according to Example 1.

[0075] Test Example 5: XRD Analysis in a Humid Environment

[0076] FIG. 7a is an XRD graph showing the state of copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention being exposed to a humid environment, FIG. 7b is an XRD graph showing the state of copper(I) oxide nanoparticles according to Example 1 of the present invention being exposed to a humid environment for 1 to 8 weeks, FIG. 7c is an XRD graph showing the state of copper(I) oxide nanoparticles according to Example 2 of the present invention being exposed to a humid environment for 1 to 8 weeks, and FIG. 7d is an XRD graph showing the state of copper(I) oxide nanoparticles according to Example 3 of the present invention being exposed to a humid environment for 1 to 8 weeks.

[0077] Referring to FIGS. 7a to 7d, it was found that the oxidation stability in a humid environment was highest for the hexahedral cuprous oxide nanoparticles according to Example 3 of the present invention, followed by the octahedral ones according to Example 2, and then the spherical ones according to Example 1. It was also found that the hexahedral cuprous oxide nanoparticles according to Example 3 maintained their crystallinity even after 8 weeks in a humid environment.

[0078] Test Example 6: XPS Analysis in a Humid Environment

[0079] FIG. 8a is an XPS graph showing the state of copper(II) oxide nanoparticles according to Examples 1 to 3 of the present invention before and after 4 weeks of exposure to a humid environment, FIG. 8b is an XPS graph showing the state of copper(II) oxide nanoparticles according to Example 1 of the present invention before and after 4 weeks of exposure to a humid environment, FIG. 8c is an XPS graph showing the state of copper(II) oxide nanoparticles according to Example 2 of the present invention before and after 4 weeks of exposure to a humid environment, FIG. 8d is an XPS graph showing the state of copper(II) oxide nanoparticles according to Example 2 of the present invention before and after 4 weeks of exposure to a humid environment, and Table 3 below shows Cu after 4 weeks of exposure to a humid environment + This is a table showing the area reduction rate.

[0080] Referring to FIGS. 8a to 8d and Table 3, it was confirmed that the surface oxidation of the hexahedral copper(I) oxide nanoparticles according to Example 3 of the present invention was lower than that of Examples 1 and 2 after 4 weeks of exposure to a humid environment, whereas in the case of Examples 1 and 2, copper ions with an oxidation state of +1 (Cu) visible around 933.0 eV + The ) peak significantly decreased after 4 weeks of exposure, and copper ions (Cu with an oxidation state of +2) 2+ It was confirmed that the peak around 934.8 eV, corresponding to ), increased. On the other hand, in Example 3, Cu after 4 weeks of exposure +The amount of change was significantly smaller than in Examples 1 and 2, so Cu + from Cu 2+ It was found that the oxidation of the furnace proceeded the slowest.

[0081] division form 4 weeks later Cu + Area reduction rate (%) Example 1 Spherical Cu2O 91.26 Example 2 Octahedral Cu2O 77.7 Example 3 Cubic Cu2O 45.7

[0082] Test Example 7: Comparison of changes in antimicrobial activity according to the duration of exposure to a humid environment

[0083] Figure 9 is a graph showing the change in antibacterial activity of copper(I) oxide nanoparticle powder according to the exposure period, in which copper(I) oxide nanoparticles according to Examples 1 to 3 of the present invention were exposed to a humid environment for 1 to 8 weeks. A (green) represents a spherical shape according to Example 1 of the present invention, B (blue) represents an octahedron according to Example 2 of the present invention, and C (red) represents a hexahedron according to Example 3 of the present invention. Referring to Figure 9, it was confirmed that the antibacterial activity decreased due to oxidation as the exposure period to a humid environment increased, and it was confirmed that the hexahedron copper(I) oxide nanoparticles according to Example 3 maintained about 90% of their antibacterial performance even after being exposed to a humid environment for 4 weeks.

[0084] Therefore, it was found that the stability upon exposure to a humid environment was highest for the hexahedral copper(II) oxide nanoparticles according to Example 3 of the present invention, followed by the octahedral nanoparticles according to Example 2, and then the spherical nanoparticles according to Example 1.

[0085] Test Example 8: Comparison of changes in antibacterial activity before and after heat treatment

[0086] Figure 10 is a graph showing the results of an antibacterial test before and after heat treatment of copper(II) oxide nanoparticles according to Examples 1 to 3 of the present invention. Referring to Figure 10, it was found that the thermal oxidation stability before and after heat treatment was highest for the hexahedral copper(II) oxide nanoparticles according to Example 3 of the present invention, followed by the octahedral nanoparticles according to Example 2, and then the spherical nanoparticles according to Example 1.

[0087] Although preferred embodiments of the present invention have been described above, those skilled in the art may modify and change the present invention in various ways by adding, changing, deleting, or adding components, etc., without departing from the spirit of the present invention as described in the claims, and such modifications and changes shall also be deemed to be included within the scope of the rights of the present invention. For example, each component described as a single unit may be implemented in a distributed manner, and components described as distributed may likewise be implemented in a combined form. The scope of the present invention is defined by the claims set forth below rather than by the above detailed description, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts thereof should be interpreted as being included within the scope of the present invention.

Claims

Claim 1 The copper(II) oxide nanoparticles comprise copper(II) oxide (Cu2O), wherein the copper(II) oxide nanoparticles have a hexahedral shape, and the specific surface area of ​​the hexahedral copper(II) oxide nanoparticles is 2 to 6 m² 2 / g, and the crystal size of the hexahedral-shaped copper(I) oxide nanoparticles is 20 to 50 nm, and the ratio of (110) crystal planes to (200) crystal planes is 1.5 to 4, copper(I) oxide nanoparticles. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 Cuprous oxide nanoparticles according to claim 1, characterized in that the cuprous oxide nanoparticles are used as an antibacterial material. Claim 9 (a) a step of preparing a copper precursor solution containing a copper precursor; (b) a step of preparing a reducing agent solution containing a reducing agent; (c) a step of preparing a mixed solution by mixing the copper precursor solution and the reducing agent solution; and (d) a step of preparing copper(I) oxide (Cu2O) nanoparticles according to claim 1 by reacting the mixed solution; wherein the copper precursor solution of step (a) further contains a base, and the reducing agent of step (b) contains ascorbic acid (C6H8O6). Claim 10 A method for preparing copper(I) oxide nanoparticles according to claim 9, characterized in that, in step (a), the copper precursor comprises one or more selected from the group consisting of Cu(NO3)2 hydrate, Cu(Ac)2 hydrate, and CuCl2 hydrate. Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 delete Claim 16 A method for preparing copper(I) oxide nanoparticles according to claim 9, characterized in that the base comprises one or more selected from the group consisting of NaOH, KOH, and NH4OH. Claim 17 delete Claim 18 A method for preparing copper(I) oxide nanoparticles according to claim 9, characterized in that, in step (c), the mixing is performed by stirring for 10 to 90 minutes.

Images