KR20160002009A - Graphene nanosheets, graphene powder, graphene ink, graphene substrate, and method for manufacturing the graphene nanosheets - Google Patents
Graphene nanosheets, graphene powder, graphene ink, graphene substrate, and method for manufacturing the graphene nanosheets Download PDFInfo
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- KR20160002009A KR20160002009A KR1020140080652A KR20140080652A KR20160002009A KR 20160002009 A KR20160002009 A KR 20160002009A KR 1020140080652 A KR1020140080652 A KR 1020140080652A KR 20140080652 A KR20140080652 A KR 20140080652A KR 20160002009 A KR20160002009 A KR 20160002009A
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/15—Nano-sized carbon materials
- C01B32/182—Graphene
- C01B32/184—Preparation
- C01B32/19—Preparation by exfoliation
Abstract
Description
The present invention relates to graphene, and more particularly to a graphene which has a positive voltage applied to a graphite foil or a graphite foil to be used as a negative electrode at least partially immersed in an acid / base mixed electrolyte solution obtained by mixing an acid solution and a base solution at a constant ratio The graphene nanofilm prepared by peeling the laminated graphite carbon layer by the application of the graphene nanofibers, the graphene powder containing the graphene nanofibers, the ink produced by using the graphene powder, And a process for producing the same.
Graphene is a two-dimensional film of a honeycomb structure made of one layer of carbon atoms. The carbon atom forms a hexagonal carbon hexagonal structure having a two-dimensional structure upon chemical bonding due to the sp 2 hybrid orbital. The aggregate of carbon atoms having this planar structure is graphene, which is about 0.34 nm, which is only one carbon atom in thickness. Such graphene is structurally and chemically very stable, has excellent charge mobility of about 100 times faster than silicon and can flow about 100 times more current than copper. Graphene with excellent transparency can have higher transparency than ITO (indium tin oxide) used as a transparent electrode. At present, various studies are being conducted to apply graphene to electronic devices using the characteristics of graphene.
On the other hand, since graphene, which is not doped or patterned, does not have energy bandgap of a general atom because a conduction band and a valence band do not meet with each other, Research is underway to make graphene have an energy bandgap by doping or patterning graphene in a specific form for utilization.
A first object of the present invention is to provide a positive electrode or graphite foil which is used as a negative electrode at least partially immersed in an acid / base mixed electrolyte solution obtained by mixing an acid solution and a base solution at a constant ratio, And to provide a graphene nanofiber manufactured by separating a laminated graphite carbon layer by applying a voltage.
A second technical problem to be solved by the present invention is to provide a method for producing graphene nanofilms.
A third technical problem to be solved by the present invention is to provide a graphene powder composed of the graphene nanofilm.
A fourth technical problem to be solved by the present invention is to provide a graphene ink produced using the graphene powder.
A fifth object of the present invention is to provide a graphene substrate produced using the graphene ink.
According to an aspect of the present invention, there is provided a graphene nanofiber comprising: a black bar or a graphite film used as an anode in which an acid solution and a base solution are at least partially immersed in an acid / And then applying a positive voltage to the foil to peel off the laminated graphite carbon layer.
According to another aspect of the present invention, there is provided a method of manufacturing a graphene nanofiber, which comprises mixing an acid solution containing SO 4 2- , NO 3 - and PO 4 3- ions and a base solution containing OH - ions A step of producing an acid / base electrolyte aqueous solution for producing the acid / base electrolyte solution, a voltage application step of applying a positive DC voltage to the black seed bar or graphite foil used as a cathode, and the step of applying the graphene nanofiber And a graphene nanofiber generation step to be produced.
In order to achieve the third technical object, the graphene powder according to the present invention is produced by washing graphene nanofibers with distilled water and drying at a temperature of 60 ° C or more for 30 minutes or more.
In order to achieve the fourth technical object, the graphene ink according to the present invention is produced by dispersing graphene powder in an organic solvent at a concentration ranging from 0.5 mg / mL to 20 mg / mL and ultrasonically washing for 5 minutes or longer.
In order to achieve the fifth technical object, the graphene substrate according to the present invention is produced by filtering graphene ink and drying it at a temperature of 80 ° C or more for 30 minutes or more.
The method of manufacturing the graphene nanofilm, the graphene powder, the graphene ink, the graphene substrate, and the graphene nanofilm according to the present invention can form a graphene nanofilm in a completely different manner from the conventional method, The characteristics such as powder, graphene ink, and graphene substrate produced by using the same can be applied to various fields of industry.
1 shows photographs of graphene powder, ink and substrate according to the present invention.
2 shows a transmission electron microscope analysis result of the graphene nanofiber according to the present invention.
3 shows XPS analysis results of the graphene powder and the substrate according to the present invention.
FIG. 4 is a graph showing the results of measurement of the thickness distribution of graphene nanofibers according to the present invention.
5 shows a scanning electron microscope (SEM) analysis result of the cross section of the graphene substrate according to the present invention.
Hereinafter, embodiments of the present invention will be described in detail. However, it should be understood that the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.
The present invention can be summarized in advance, in which an aqueous solution of an acid / base mixed electrolyte composed of an acid solution containing SO 4 2- , NO 3 - and PO 4 3- ions and a basic solution containing OH - Applying a positive (+) voltage to the cathode electrode of the foil and applying an electrochemical reaction using a metal wire and a metal foil as anode electrodes induces local oxygen-functionalization of the laminated graphite carbon layer, Grains, inks, and substrates produced by separating, finely dispersing, and drying graphene nanofiltration films, and producing them.
The graphite foil and the graphite foil used to produce graphene nanofibers are produced by processing graphite powder and expanded graphite to form graphite foil in the form of a cylindrical cylinder or film.
Herein, oxygen-functionalization refers to a process of fabricating graphene nanofilms by peeling the oxygen-functional group between the carbon layers of the laminated graphite and removing the oxygen-functional group.
The acid electrolyte aqueous solution containing SO 4 2- , NO 3 - and PO 4 3- ions is oxidized by SO 2 , NO 2 and PO 3 gases in the black rods and graphite foil cathodes during the electrochemical reaction when DC voltage is applied, The peeling of the carbon layer can be easily induced.
The aqueous base electrolyte solution containing OH - ions can generate OH - ions and OH · (hydroxyl radicals) when the DC voltage is applied during the electrochemical reaction to easily induce localized oxygen functionalization between the laminated graphite carbon layers.
During the electrochemical reaction, the applied DC voltage is obtained by electrolyzing water in an acid / base mixed electrolyte aqueous solution to generate OH - ions, OH (hydroxyl radical) and O (oxygen radical) It is possible to easily induce local oxygen functionalization and peeling between carbon layers.
In the present invention, an acid / base electrolyte aqueous solution composed of an acid solution containing SO 4 2- , NO 3 - and PO 4 3- ions and a basic solution containing OH - ions is mixed using the characteristics of the above chemical reaction, / Electrophoretic reaction using a black seed bar or graphite foil as an anode in an aqueous base electrolyte solution and applying a DC voltage of positive (+) to the black bar and the graphite foil, , The graphene nanofilm formed by the above process is separated, dispersed and dried to produce graphene powder, ink and substrate.
The step of mixing and preparing an acid / base mixed electrolyte aqueous solution comprising an acid solution containing SO 4 2- , NO 3 - and PO 4 3- ions and a base solution containing OH - ions as described above may be carried out by mixing sulfate, nitrate, phosphate and sulfuric acid (NaOH, KOH) containing nitric acid (H 2 SO 4 ), nitric acid (HNO 3 ), phosphoric acid (H 3 PO 4 ) and a hydroxide and hydroxyl group or a mixture thereof in an aqueous solution. In this case, the mixing ratio (base solution / acid solution) of the acid solution and the base solution may be in the range of about 0.05 to 20, for example, the molar ratio of H 2 SO 4 : NaOH = 1: 2 .
The step of peeling / manufacturing the graphene nanofiltration film using the electrochemical reaction may be performed by using an electrochemical reaction using a graphite foil as a cathode and a metal wire as a cathode foil and a cathode foil as an anode electrode. ) Of the DC voltage of the DC voltage. The voltage applied to the graphite cathode electrode is preferably in the range of + 1V (Volt) to + 20V. According to one embodiment, it is possible to effectively lower the electrochemical applied voltage to + 1V by using an acid / base mixed electrolyte aqueous solution, and to lower the concentration of the acid / base mixed electrolyte aqueous solution used to 0.05M.
The radius of the graphene nanofiber formed through the above process is 0.1 to 10 탆, the thickness is 0.5 to 5 nm, and the chemical composition ratio (C / O ratio) of carbon (C) to oxygen (O) But is not limited thereto. The graphene nanofiber can be formed as a single layer or a multilayer, and when the radius, the thickness, and the chemical composition are within the above ranges, the specific surface area is very large and can have high electrical conductivity.
Separation, dispersion and drying of the separated and manufactured graphene nanofilm can produce graphene powder, ink, and substrate as described below.
The graphene powder can be obtained by filtering the graphene nanofibers produced through the above-described process, and washing and drying the graphene nanofibers. At this time, washing of the graphene powder may be performed with distilled water and a polar organic solvent, and drying may be performed at a temperature of 60 ° C or higher.
The graphene ink can be obtained by ultrasonically dispersing the graphene powder in a polar organic solvent such as dimethylformamide, N-methyl-2-pyrrolidone, ethylene glycol, etc., and the concentration of the ink is 0.5 mg / ml to 20 mg / ml .
The graphene substrate can be prepared by filtering a graphene ink having a pore radius of 20 nm or more and drying the graphene ink in the range of 0.5 mg / mL to 20 mg / mL, and the thickness of the substrate is in the range of 0.5 mm to 10 cm desirable. Drying of the graphene substrate should be performed at a temperature of 80 ° C or higher.
The thickness of a graphene substrate manufactured using graphene ink can be easily adjusted and a two-dimensional alignment of graphene nanofibers can be induced to produce a flexible substrate having high electrical conductivity.
FIG. 1 is a photograph of a result obtained by separating, dispersing, and drying a graphene nanofiber according to the present invention to prepare a graphene powder, an ink, and a substrate.
Hereinafter, specific examples of the present invention will be described. However, the embodiments described below are only intended to illustrate or explain the present invention, and thus the present invention should not be limited thereto. In addition, contents not described here can be derived from a technically skilled person skilled in the art, and a description thereof will be omitted.
Example
1. A 0.1 M aqueous sulfuric acid solution (H 2 SO 4 ) is mixed with the same volume as the aqueous 0.2 M sodium hydroxide solution and stirred for 5 minutes or more to obtain an acid / base mixed electrolyte aqueous solution.
2. Wash the graphite foil, graphite foil and metal foil used as a cathode and metal foil used as a cathode with distilled water and ethanol, and dry at a temperature of 60 ° C or more for 10 minutes or more.
3. The washed and dried graphite foil electrode was immersed in the aqueous solution of the acid / base mixed electrolyte, and a voltage of + 3V was applied thereto. The electrode was subjected to an electrical reaction at a temperature range of 2 to 80 ° C for 30 minutes to peel off the graphene nanofiber · Manufacture.
4. The graphene nanofibers produced are filtered, washed with distilled water, and dried at a temperature of 60 ° C or higher for 30 minutes or longer to prepare a graphene powder.
5. The prepared graphene powder is dispersed in an organic solvent at a concentration of 0.5 mg / mL to 20 mg / mL and ultrasonically washed for 5 minutes or longer to prepare a graphene ink.
6. Graphene ink is filtered using a membrane having a pore radius of 20 nm or more and dried at a temperature of 80 ° C or more for 30 minutes or more to prepare a graphene substrate.
Hereinafter, data analyzed for objects according to the present invention will be described.
1. Morphology analysis of graphene nanofibers
2 shows a transmission electron microscope analysis result of the graphene nanofiber according to the present invention.
Referring to the results of measurement by Cs-Corrected Scanning Transmission Electron Microscopy shown in FIG. 2, graphene nanofibers having a radius of several tens of micrometers peeled from the stacked graphite carbon layer are single or two or three layers thick And a graphene nanofiber having a graphene structure.
2. Chemical composition analysis of graphene powder and substrate
3 shows XPS analysis results of the graphene powder and the substrate according to the present invention.
Referring to the analysis results of the chemical composition of the graphene powder and the substrate shown in FIG. 3 measured by X-ray photoelectron spectroscopy (XPS, AXIS Ultra DLD, Kratos), the chemical composition of the graphene powder and the graphene substrate Carbon and oxygen, and the carbon to acid ratio (C / O ratio) is 12.4.
3. Analysis of thickness of graphene nanofibers
FIG. 4 is a graph showing the results of measurement of the thickness distribution of graphene nanofibers according to the present invention.
The graphene nanomembrane according to the present invention is characterized in that the graphene nanomembrane according to the present invention comprises a graphene nanofiber layer, It can be seen that at least 80% of the final product is composed of a graphene nanofiber with a tri-layer or less.
4. Analysis of shape and electrical conductivity of graphene substrate
5 shows a scanning electron microscope (SEM) analysis result of the cross section of the graphene substrate according to the present invention.
Referring to FIG. 5, the graphene substrate was formed with a graphene film having a thickness of about 200 탆 composed of graphene nanofibers aligned in two dimensions, and the graphene nanofibers were uniformly aligned and had a relatively flat surface . As a result of 4-probe measurement, the sheet resistance is about 5 Ω / sq, indicating that the graphene substrate has high electrical conductivity.
100: Grain powder
200: Graphene Ink
300: Graphene substrate
Claims (11)
Wherein the graphene nanofiber has an average radius of 0.1 占 퐉 to several tens 占 퐉.
Wherein the graphene nanofiber has an average thickness of 0.5 nm to 5 nm.
Wherein the graphene nanofiber is formed as a single layer or a multilayer.
A step of producing an acid / base electrolyte aqueous solution by mixing an acid solution containing SO 4 2- , NO 3 - and PO 4 3- ions with a base solution containing OH - ions to prepare an aqueous acid / base electrolyte solution;
A voltage applying step of applying a positive DC voltage to the black bar or the graphite foil used as a cathode; And
And a graphene nanofiber film forming step in which the graphene nanofiber film is peeled off.
Characterized in that a local oxygen functionalization of the graphite carbon layer stacked by a positive DC voltage applied to the graphite foil or the graphite foil used as a negative electrode is induced and the graphene nanofiber is peeled off. A method of manufacturing a fin nanofilm.
The water in the aqueous acid / base electrolyte solution is electrolyzed by the direct current voltage applied to the graphite foil or the graphite foil used as a cathode to generate OH - ions, OH (hydroxyl radical), and O Oxygen radicals are generated to induce localized oxygen functionalization of the laminated graphite carbon layer, and the grafting with the graphene nanofiltration film is performed.
In the aqueous acid / base electrolyte solution containing SO 4 2- , NO 3 - and PO 4 3- ions by the positive DC voltage applied to the graphite foil or the graphite foil used as the cathode, Layer is oxidized to SO 2 , NO 2, and PO 3 gas.
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| KR20170111208A (en) * | 2016-03-25 | 2017-10-12 | 전자부품연구원 | Graphene ink and manufacturing method thereof |
| KR20180038321A (en) * | 2016-10-06 | 2018-04-16 | 주식회사 멕스플로러 | Metal-coatable Graphene ink, method of fabricating the same, method of coating metal surface with metal-coatable graphene ink and metals coated with graphene |
| CN108117065A (en) * | 2017-12-14 | 2018-06-05 | 北京化工大学 | A kind of method that graphene is prepared using alternative current stripping |
| WO2020050436A1 (en) * | 2018-09-07 | 2020-03-12 | (주)드림팩토리 | Method for producing graphene quantum dots |
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2014
- 2014-06-30 KR KR1020140080652A patent/KR20160002009A/en not_active Application Discontinuation
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| KR20170111208A (en) * | 2016-03-25 | 2017-10-12 | 전자부품연구원 | Graphene ink and manufacturing method thereof |
| KR20180038321A (en) * | 2016-10-06 | 2018-04-16 | 주식회사 멕스플로러 | Metal-coatable Graphene ink, method of fabricating the same, method of coating metal surface with metal-coatable graphene ink and metals coated with graphene |
| CN108117065A (en) * | 2017-12-14 | 2018-06-05 | 北京化工大学 | A kind of method that graphene is prepared using alternative current stripping |
| CN108117065B (en) * | 2017-12-14 | 2020-04-17 | 北京化工大学 | Method for preparing graphene by adopting alternate current stripping |
| WO2020050436A1 (en) * | 2018-09-07 | 2020-03-12 | (주)드림팩토리 | Method for producing graphene quantum dots |
| US20210316995A1 (en) * | 2018-09-07 | 2021-10-14 | Dream Factory Co., Ltd. | Method for producing graphene quantum dots |
| US11718531B2 (en) | 2018-09-07 | 2023-08-08 | Dxome Co., Ltd. | Method for producing graphene quantum dots |
| KR20210065061A (en) * | 2019-11-26 | 2021-06-03 | (주)에버켐텍 | Debonding Layer and Method for Manufacturing the Same, Information Display Element and Method for Manufacturing the Same |
| CN113173579A (en) * | 2020-06-09 | 2021-07-27 | 吉林省格瑞节能科技有限公司 | Macroscopic preparation method of graphene |
| CN113173579B (en) * | 2020-06-09 | 2022-05-13 | 吉林省格瑞节能科技有限公司 | Macroscopic quantity preparation method of graphene |
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