High-conductivity mxene and manufacturing method therefor

Abstract

An embodiment of the present invention provides high-conductivity MXene and a manufacturing method therefor, the high-conductivity MXene having an average electrical conductivity of 25,000 S / cm or more by improved electrical properties of MXene through the mitigation of pores present in the surface of MXene, the method comprising the steps of: providing a MAX structure; removing an A layer from the provided MAX structure to form an MXene layer; and delaminating the formed MXene layer to adjust the thickness and structure, wherein the step of forming the MXene layer comprises a step of adding the provided MAX structure to a solution containing HCl and LiF, followed by reaction.

Description

High-conductivity MXENE and its manufacturing method

[0001] The present invention relates to a high-conductivity MXene and a method for producing the same, and more particularly, to a high-conductivity MXene having an average electrical conductivity of 25,000 S / cm or more and a method for producing the same by improving the electrical properties of MXene through alleviation of defects present on the surface of MXene.

[0002] Materials with high conductivity and electrical properties are widely utilized in modern science and industry. They play a crucial role in a wide range of applications, including electrical and electronic devices, energy storage and conversion systems, sensors, and amplifiers.

[0003] However, existing materials have limitations such as being expensive or difficult to manufacture and process, so there is a need to develop more economical and efficient materials.

[0004] MXene, a recently emerged novel material, holds exciting potential to address these challenges. More specifically, MXene is a two-dimensional material composed of a core conductive layer of transition metal carbide or transition metal nitride and hydrophilic functional groups such as -OH, -F, and -O. These characteristics allow MXene to exhibit outstanding electrical properties while also allowing for the utilization of surface chemical functionality.

[0005] The high conductivity of MXene demonstrates its potential as an effective current conductor in electrical and electronic devices. At the same time, MXene possesses excellent chemical stability and mechanical strength, enabling its application as reliable components and materials. These properties are expected to open up innovative applications in diverse fields, including energy storage and conversion systems, sensors, and transparent and flexible electronic devices.

[0006] However, in the case of conventional technology, there were cases where surface defects (pores) of 10 nm or larger in size were observed on the surface during the process of forming MXene. If such defects exist, there is a problem that the electrical properties of MXene deteriorate.

[0007] [Prior patent literature]

[0008] Republic of Korea Patent No. 10-2365011

[0009]

[0010] The technical problem to be achieved by the present invention is to provide a high-conductivity MXene and a method for manufacturing the same, which can improve the electrical properties of MXene by alleviating defects existing on the surface of MXene.

[0011] The technical problems to be solved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0012]

[0013] In order to achieve the above technical task, one embodiment of the present invention provides a method for manufacturing high-conductivity MXene.

[0014] The method for manufacturing the high-conductivity MXene according to one embodiment of the present invention is as follows:

[0015] A step of providing a MAX structure; a step of removing an A layer from the provided MAX structure to form an MXene layer; and a step of controlling the thickness and structure by separating (delaminating) the formed MXene layer.

[0016] There may be a method for manufacturing a high-conductivity MXene, characterized in that the step of forming the MXene layer includes a step of adding the MAX structure provided to a solution containing HCl and LiF and causing a reaction.

[0017]

[0018] In addition, according to one embodiment of the present invention, there may be a method for manufacturing a high-conductivity MXene, characterized in that the MAX structure is a structure in which the M element is Ti, the A element is Al, and the X element is C.

[0019]

[0020] In addition, according to one embodiment of the present invention, there may be a method for manufacturing a high-conductivity MXene, characterized in that the step of providing the MAX structure includes the steps of: forming a MAX powder by ball milling a precursor of the MAX structure; forming a MAX block by sintering the MAX powder; washing the formed MAX block with a strong acid; and neutralizing the MAX block reacted with the strong acid.

[0021]

[0022] In addition, according to one embodiment of the present invention, there may be a method for manufacturing a high-conductivity MXene, characterized in that the precursor of the MAX structure is a material including TiC, Ti, and Al.

[0023]

[0024] In addition, according to one embodiment of the present invention, there may be a method for manufacturing a high-conductivity MXene, characterized in that the step of neutralizing the MAX block includes the steps of adding distilled water to the MAX block and centrifuging it; adding distilled water to the centrifuged MAX block and washing it by filtering under reduced pressure; and drying the washed MAX block.

[0025] In addition, according to one embodiment of the present invention, there may be a method for manufacturing high-conductivity MXene, characterized in that the centrifuging step is performed at 4000 rpm to 6000 rpm.

[0026] In addition, according to one embodiment of the present invention, there may be a method for manufacturing a high-conductivity MXene, characterized in that after the step of neutralizing the MAX block, the step of washing the MAX block with a strong acid is repeated once more.

[0027]

[0028] In addition, according to one embodiment of the present invention, the step of adding the MAX structure to the solution containing HCl and LiF and reacting the same includes the step of forming an acidic solution by adding a strong acid to distilled water; the step of adding LiF powder within 10 seconds after the step of forming the acidic solution; and the step of completely dissolving the LiF powder.

[0029] There may be a method for manufacturing a high-conductivity MXene characterized in that the LiF powder can be easily dissolved through the heat of reaction between distilled water and a strong acid generated in the step of forming the above acidic solution.

[0030]

[0031] In addition, according to one embodiment of the present invention, there may be a method for producing a high-conductivity MXene, characterized in that the solution containing HCl and LiF contains HCl and LiF in a molar ratio of 1:1 to 2:1.

[0032]

[0033] In addition, according to one embodiment of the present invention, there may be a method for producing a high-conductivity MXene, characterized in that the step of adding the MAX structure to the solution containing HCl and LiF and reacting the same includes a first step of stirring at 500 rpm to 600 rpm after adding the MAX structure; and a second step of stirring at 300 rpm to 400 rpm.

[0034]

[0035] In addition, according to one embodiment of the present invention, there may be a method for manufacturing a high-conductivity MXene, characterized in that the first stirring step is performed for 20 minutes or less, and the second stirring step is performed for 20 to 30 hours.

[0036]

[0037] In addition, according to one embodiment of the present invention, there may be a method for manufacturing a high-conductivity MXene, characterized in that the step of controlling the thickness and structure by separating (delaminating) the MXene layer includes the step of first centrifuging a solution including the formed MXene layer 5 to 10 times; and the step of separating a precipitate after the first centrifugation and then centrifuging it a second time.

[0038]

[0039] To achieve the above technical task, another embodiment of the present invention provides a high-conductivity MXene.

[0040] According to one embodiment of the present invention, the high-conductivity MXene is

[0041] Manufactured according to the above-described high-conductivity MXene manufacturing method, the number of defects larger than 10 nm on the surface of the MXene is 10 / μm. 2 It may be a high-conductivity MXene characterized by the following.

[0042]

[0043] According to one embodiment of the present invention, by improving the electrical properties of MXene through alleviation of defects present on the surface of MXene, a high-conductivity MXene having an average electrical conductivity of 25,000 S / cm or more and a method for producing the same can be provided.

[0044] According to one embodiment of the present invention, the electrical properties of MXene can be improved by alleviating defects present on the surface of MXene.

[0045]

[0046] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the composition of the invention described in the claims.

[0047]

[0048] Figure 1 is a flowchart illustrating a method for manufacturing MXene according to one embodiment of the present invention.

[0049] FIG. 2 is a flowchart illustrating a step of providing a MAX structure among the MXene manufacturing methods according to one embodiment of the present invention.

[0050] Figure 3 is an actual photograph of TiC, Ti, Al powder, ball mill, and zirconia ball used in a method for manufacturing MXene according to one embodiment of the present invention.

[0051] Figure 4 is an actual photograph of MAX powder divided into equal parts and used in a method for manufacturing MXene according to one embodiment of the present invention.

[0052] Figure 5 is an actual photograph of a furnace used in a method for manufacturing MXene according to one embodiment of the present invention.

[0053] FIG. 6 is an actual photograph of a MAX structure obtained through a step of obtaining a MAX structure in a method for manufacturing MXene according to an embodiment of the present invention.

[0054] FIG. 7 is an actual photograph of a conical tube used when performing a second centrifugation step by adding distilled water after performing a first centrifugation on a solution containing an MXene layer, among the MXene manufacturing methods according to one embodiment of the present invention.

[0055] FIG. 8 is an actual photograph of a method for manufacturing MXene according to an embodiment of the present invention, in which a solution including an MXene layer is centrifuged, and then the suspended matter (MXene) and the precipitate (MAX structure) are separated and stored.

[0056] Figure 9 is a graph showing data measuring the electrical conductivity of a high-conductivity MXene according to an embodiment of the present invention in (a) and (b), respectively, and (c) showing data measuring the electrical conductivity of a conventionally disclosed MXene.

[0057] Figures 10(a) and (b) are enlarged images of the surface of a high-conductivity MXene according to an embodiment of the present invention, and (c) and (d) are enlarged images of the surface of a conventionally disclosed MXene.

[0058]

[0059] Hereinafter, the present invention will be described with reference to the attached drawings. However, the present invention can be implemented in various different forms and is therefore not limited to the embodiments described herein. In the drawings, irrelevant parts have been omitted for clarity of description, and similar parts have been designated with similar reference numerals throughout the specification.

[0060] Throughout the specification, when a part is said to be "connected (connected, contacted, or coupled)" to another part, this includes not only cases where it is "directly connected," but also cases where it is "indirectly connected" with another member in between. Furthermore, when a part is said to "include" a component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0061] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this specification, it should be understood that the terms "comprises" or "has" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0062]

[0063] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings.

[0064] A method for manufacturing high-conductivity MXene according to one embodiment of the present invention is described.

[0065] Figure 1 is a flowchart illustrating a method for manufacturing MXene according to one embodiment of the present invention.

[0066] An example of the above embodiment is described with reference to Fig. 1.

[0067]

[0068] Referring to FIG. 1, as an example of the above embodiment, the method includes a step (S10) of providing a MAX structure; a step (S20) of removing an A layer from the provided MAX structure to form an MXene layer; and a step (S30) of separating the formed MXene layer to adjust the thickness and structure.

[0069] There may be a method for manufacturing a high-conductivity MXene, characterized in that the above MAX structure is a structure in which the M element is Ti, the A element is Al, and the X element is C, and the step of forming the MXene layer includes a step of adding the provided MAX structure to a solution containing HCl and LiF and causing a reaction.

[0070]

[0071] The above MAX structure is a ceramic material composed of a combination of three elements: a transition metal (M), a group 13 or 14 element (A), and carbon or nitrogen (X).

[0072] The above MAX structure is M n+1 AX n It has a chemical formula and a layered structure.

[0073]

[0074] The above MXene is a ceramic material with a two-dimensional planar structure, and is a material composed of an atomic-thick layer in which carbon or nitrogen is bonded to a transition metal.

[0075] The above MXene can be obtained by removing the A element layer from the MAX structure, and the step of removing the A element layer is the “etching” step (S20). In other words, the etching step (S20) refers to the process of chemically removing the A layer of the MAX structure to expose the MXene layer.

[0076] The above process can be carried out using a method of chemically corroding or thermally decomposing the A layer, and representative methods include methods performed using strong acid or heat treatment.

[0077] In one embodiment of the present invention, the A layer is removed through a step of adding the MAX structure provided to a solution containing HCl and LiF and causing a reaction, thereby forming an MXene layer.

[0078]

[0079] At this time, as described above, when using a solution containing HCl and LiF, there is an advantage in terms of safety because a hydrofluoric acid (HF) solution is not directly used.

[0080]

[0081] The method of using the solution containing the above HCl and LiF is an in-situ HF etching method, so that the above HCl and LiF generate HF in real time through a chemical reaction, thereby selectively removing only Al from Ti3AlC2.

[0082]

[0083] In the case of the above MAX structure, since a wide variety of combinations are possible as described above, a wide variety of types of MXene obtained from the above MAX structure may also exist.

[0084]

[0085] During the manufacturing process of MXene, the step of “delamination” (S30) of the MXene layer refers to the process of mechanically separating the MXene layer to obtain the desired thickness and structure.

[0086] The above step (S30) is used to make the MXene layer thinner or in a specific shape or to mix it with other materials to make a composite material.

[0087]

[0088] In the above delamination step (S30), first, the MXene layer is separated through a series of mechanical processing steps.

[0089] Through this, the thickness of the MXene layer can be controlled or processed into various shapes, for which mechanical pressure, shear force, or other mechanical treatment can be applied.

[0090] Additionally, by separating the MXene layers, it can be utilized to control the interlayer spacing and structure, thereby adjusting the properties of the MXene or optimizing it for specific applications.

[0091]

[0092] As an example of the above embodiment, there may be a method for manufacturing a high-conductivity MXene, characterized in that the MAX structure is a structure in which the M element is Ti, the A element is Al, and the X element is C.

[0093] More specifically, the MAX structure may be Ti3AlC2.

[0094]

[0095] FIG. 2 is a flowchart illustrating a step of providing a MAX structure among the MXene manufacturing methods according to one embodiment of the present invention.

[0096] An example of the above embodiment is described with reference to FIG. 2.

[0097]

[0098] Referring to FIG. 2, as an example of the embodiment, there may be a method for manufacturing a high-conductivity MXene, characterized in that the step (S10) of providing the MAX structure includes the steps of: a step (S2) of forming a MAX powder by ball-milling a precursor of the MAX structure; a step (S3) of forming a MAX block by sintering the MAX powder; a step (S4) of washing the formed MAX block with a strong acid; and a step (S5) of neutralizing the MAX block reacted with the strong acid.

[0099]

[0100] As an example of the above embodiment, there may be a method for manufacturing a high-conductivity MXene, characterized in that the precursor of the MAX structure is a material including TiC, Ti, and Al.

[0101]

[0102] Figure 3 is an actual photograph of TiC, Ti, Al powder, ball mill, and zirconia ball used in a method for manufacturing MXene according to one embodiment of the present invention.

[0103] Figure 4 is an actual photograph of MAX powder divided into equal parts and used in a method for manufacturing MXene according to one embodiment of the present invention.

[0104] Figure 5 is an actual photograph of a furnace used in a method for manufacturing MXene according to one embodiment of the present invention.

[0105] An example of the above embodiment is described with reference to FIGS. 3 to 5.

[0106]

[0107] Referring to FIG. 3, it can be confirmed that TiC, Ti, and Al powders are prepared as precursors of the MAX structure, and ball milling is performed using zirconia balls in a ball mill.

[0108]

[0109] At this time, the TiC, Ti, and Al powders provided as precursors of the MAX structure may be provided in an amount of 1 to 2 parts by weight of the Ti and 1 to 3 parts by weight of the TiC per 1 part by weight of the Al powder.

[0110] More preferably, for 1 part by weight of the Al powder, 1 part by weight of the Ti and 2 parts by weight of the TiC may be provided.

[0111] A MAX structure of Ti3AlC2 can be formed by ball milling at the above mass ratio.

[0112]

[0113] As an example of the above embodiment, there may be a method for manufacturing a high-conductivity MXene, characterized in that the step of forming a MAX powder by ball milling a precursor of the MAX structure is performed at 50 RPM to 100 RPM for 18 to 24 hours.

[0114]

[0115] Referring to FIGS. 4 and 5, it can be confirmed that the formed MAX powder is divided into equal parts and placed in a boat, and then the boat containing the divided MAX powder is placed in a furnace and a sintering step is performed.

[0116]

[0117] In the case of the above sintering step, it can be carried out under an inert gas atmosphere, and more specifically, it can be carried out under an argon gas atmosphere.

[0118] Additionally, in the case of the above sintering step, an inert gas must be flowed for at least 30 minutes, and only then can sintering be performed.

[0119] At this time, there may be a method for manufacturing high-conductivity MXene characterized in that the sintering is performed at a temperature range of 1300°C to 1500°C for 8 to 12 hours.

[0120] When sintering is performed for 8 to 12 hours in a temperature range of 1300°C to 1500°C as described above, the TI3AlC2 phase can be easily formed.

[0121] At this time, when the sintering is performed at a temperature lower than 1300°C or higher than 1500°C, a problem may arise in which other phases, such as TiC or Ti2AlC, are formed in addition to the TI3AlC2 phase.

[0122]

[0123] In the case of the step of washing the MAX block formed above with strong acid,

[0124] The high-conductivity MAX block that has completed the above sintering is placed in a dedicated HCl washing tank. Afterwards, an HCl aqueous solution is added.

[0125] The above HCl aqueous solution is a solution in which distilled water (DI water) and HCl are mixed in a volume ratio of 1:2 to 1:4.

[0126] There may be a method for manufacturing a high-conductivity MXene, characterized in that the volume (ml) value of the above HCl aqueous solution has a value corresponding to 10 times the weight (g) value of the above MAX block.

[0127] For example, if the MAX block is 60g, a total of 600ml of solution must be prepared. At this time, 150ml to 200ml of DI water and 400ml to 450ml of HCl should be added to make a total of 600ml of solution.

[0128]

[0129] In the above step, the HCl aqueous solution plays a role in removing impurities, and when the concentration of the HCl aqueous solution and the numerical ratio with the MAX block are used, the impurities can be removed most effectively.

[0130]

[0131] In the step of washing the MAX block formed above with strong acid, first put DI water into the container, and before adding HCl, put in a large stirring bar and stir at 200 RPM to 500 RPM.

[0132] Afterwards, the reaction can be carried out for 40 to 50 hours by slowly pouring HCl.

[0133]

[0134] As an example of the above embodiment, there may be a method for manufacturing a high-conductivity MXene, characterized in that the step of neutralizing the MAX block includes the steps of adding distilled water to the MAX block and centrifuging it; adding distilled water to the centrifuged MAX block and washing it by filtering under reduced pressure; and drying the washed MAX block.

[0135]

[0136] FIG. 6 is an actual photograph of a MAX structure obtained through a step of obtaining a MAX structure in a method for manufacturing MXene according to an embodiment of the present invention.

[0137] An example of the above embodiment is described with reference to FIG. 6.

[0138]

[0139] Referring to Figure 6, the centrifugation step is performed by adding the MAX block and DI water to the centrifuge tank,

[0140] Afterwards, you can see that everything except the sediment is removed, DI water is filled, and then the process is carried out through vacuum filtration.

[0141] At this time, while performing the vacuum filtration, continuously pour in DI water to make the solution neutral.

[0142]

[0143] After completing the washing process through the above process and drying for more than one day, a MAX structure can be obtained as shown in (c) of the above Fig. 6.

[0144] Afterwards, the above-mentioned dried MAX structure can be filtered through a 75 μm sieve and stored.

[0145] As an example of the above embodiment, there may be a method for manufacturing high-conductivity MXene, characterized in that the centrifuging step is performed at 4000 rpm to 6000 rpm.

[0146] As an example of the above embodiment, there may be a method for manufacturing high-conductivity MXene, characterized in that the centrifuging step is performed for 5 to 10 minutes.

[0147]

[0148] As an example of the above embodiment, there may be a method for manufacturing a high-conductivity MXene characterized in that, after the step of neutralizing the MAX block, the step of washing the MAX block with a strong acid is repeated once more.

[0149] At this time, the step of neutralizing the MAX block means a step of washing the MAX block by centrifugation and vacuum filtration, and then drying it.

[0150]

[0151] As described above, once the drying step is completed, the step of washing the MAX block with a strong acid can be repeated once more, thereby removing any remaining impurities, which ultimately helps to form a more defect-free and uniform MXene.

[0152] At this time, if the step of washing with the strong acid is repeated more than once, it is not only not economically efficient, but there is also a problem that the material may be deteriorated by the repeated washing, so it is most preferable to repeat the process only once more as in the embodiment of the present invention.

[0153]

[0154] As an example of the above embodiment, the step of adding the MAX structure provided to the solution containing HCl and LiF and causing a reaction includes the step of forming an acidic solution by adding a strong acid to distilled water; the step of adding LiF powder within 10 seconds after the step of forming the acidic solution; and the step of completely dissolving the LiF powder.

[0155] There may be a method for manufacturing a high-conductivity MXene characterized in that the LiF powder can be easily dissolved through the heat of reaction between distilled water and a strong acid generated in the step of forming the above acidic solution.

[0156]

[0157] At this time, after adding HCl to DI water, LiF powder is added within 10 seconds. This is to more effectively dissolve LiF powder by utilizing the heat of reaction between DI water and HCl.

[0158]

[0159] Most preferably, the step of adding LiF powder immediately after the step of forming the acidic solution has the best effect.

[0160]

[0161] As an example of the above embodiment, there may be a method for producing a high-conductivity MXene, characterized in that the solution containing the HCl and LiF contains the HCl and LiF in a molar ratio of 1:1 to 2:1.

[0162]

[0163] At this time, if the LiF is used at a ratio higher than the ratio above, it is difficult to remove the LiF in a later stage, so the number of washings required increases, which is not only economically inefficient, but also presents the problem that too much washing may deteriorate the material.

[0164] In addition, as an example of the above embodiment, there may be a method for manufacturing a high-conductivity MXene characterized in that the LiF is included in a ratio of 2 g to 5 g in the HCl 5 M to 10 M aqueous solution.

[0165] The amounts of the above HCl and LiF are proportional to the in-situ HF concentration. However, if the generated HF concentration is too high, there is a problem that it becomes difficult to control etching and defects are likely to occur.

[0166]

[0167] As an example of the above embodiment, there may be a method for producing a high-conductivity MXene, characterized in that the step of adding the MAX structure to a solution containing the HCl and LiF and causing a reaction includes a first step of stirring at 500 rpm to 600 rpm after adding the MAX structure; and a second step of stirring at 300 rpm to 400 rpm.

[0168] As an example of the above embodiment, there may be a method for manufacturing a high-conductivity MXene, characterized in that the first stirring step is performed for 20 minutes or less, and the second stirring step is performed for 20 to 30 hours.

[0169]

[0170] As an example of the above embodiment, there may be a method for manufacturing a high-conductivity MXene, characterized in that the step of controlling the thickness and structure by separating (delaminating) the MXene layer includes the step of first centrifuging a solution including the formed MXene layer 5 to 10 times; and the step of separating a precipitate after the first centrifugation and then centrifuging it a second time.

[0171]

[0172] Through the above first centrifugation step, the solution can be separated into a supernatant and a precipitate. At this time, the supernatant corresponding to the acidic solvent is discarded, and the precipitate can be obtained. This process is repeated 5 to 10 times, discarding the supernatant each time.

[0173]

[0174] The above first centrifugation step may be performed at 6000 rpm to 8000 rpm, and each time may be performed for 5 to 10 minutes.

[0175]

[0176] Considering the viscosity, density, size, etc. of the MXene formed with the acidic solvent used in one embodiment of the present invention, the most effective separation can be achieved by centrifuging 5 to 10 times, with each time 5 to 10 minutes at 6000 rpm to 8000 rpm.

[0177]

[0178] FIG. 7 is an actual photograph of a conical tube used when performing a second centrifugation step by adding distilled water after performing a first centrifugation on a solution containing an MXene layer, among the MXene manufacturing methods according to one embodiment of the present invention.

[0179] FIG. 8 is an actual photograph of a method for manufacturing MXene according to an embodiment of the present invention, in which a solution including an MXene layer is centrifuged, and then the suspended matter (MXene) and the precipitate (MAX structure) are separated and stored.

[0180]

[0181] After the first centrifugation step is completed, the supernatant is discarded, DI water is added to the remaining sediment, and hand shaking and vortexing can be performed until the sediments attached to the wall are completely loosened.

[0182] Referring to Figure 7, the appearance before and after the contents were transferred to the conical tube and shaking was performed after the sediment attached to the wall was completely dissolved can be confirmed.

[0183] After shaking is performed in the above conical tube, the second centrifugation step can be performed in the conical tube as is.

[0184]

[0185] The second centrifugation step may be performed at 3000 rpm to 4000 rpm for 5 to 10 minutes.

[0186] Through the above second centrifugation step, the MAX structure and MXene can be separated, wherein the suspended matter is MXene and the precipitate is the MAX structure.

[0187]

[0188] Considering the viscosity, density, size, etc. of the above MXene and MAX structures, centrifugation at 3000 rpm to 4000 rpm for 5 to 10 minutes as described above can be most effectively separated.

[0189]

[0190] Referring to Figure 8, it can be confirmed that the floating matter (MXene) and the sediment (MAX structure) were separated and stored through the second centrifugation step.

[0191]

[0192] A high-conductivity MXene according to another embodiment of the present invention is described.

[0193]

[0194] As an example of the above embodiment, a high-conductivity MXene manufactured according to the above-described method for manufacturing MXene has 10 / μm of defects larger than 10 nm on the surface of the MXene. 2 There may be a high-conductivity MXene characterized by the following.

[0195] Figures 10(a) and (b) are enlarged images of the surface of a high-conductivity MXene according to an embodiment of the present invention, and (c) and (d) are enlarged images of the surface of a conventionally disclosed MXene.

[0196] An example of the above embodiment is described with reference to Fig. 10.

[0197]

[0198] Referring to Figure 10, the surface of the previously disclosed MXene has surface defects (pores) of 10 nm or larger in size and 1 μm or larger. 2 It can be confirmed that there are more than 100 of them per area.

[0199] On the other hand, it can be confirmed that no visible surface defects (pores) larger than 10 nm are observed on the surface of the high-conductivity MXene according to an example of the above embodiment.

[0200] Since the above surface defect is a problem directly related to the electrical properties of MXene, it can be expected that the MXene according to the example of the above embodiment will show a better effect in electrical properties such as electrical conductivity, as the surface defect is greatly alleviated.

[0201]

[0202] Manufacturing Example 1. Manufacturing of MXene according to one embodiment of the present invention.

[0203]

[0204] 1. MAX structure preparation step

[0205] - Put 30g, 15g, and 15g of TiC, Ti, and Al powders into the ball mill container, respectively, add zirconia balls, and ball mill at 70 RPM for 24 hours.

[0206]

[0207] - Divide 60g of the MAX powder obtained by ball milling into 6 equal parts and place them in a boat. (See Fig. 4)

[0208]

[0209] Place a boat containing 60g of the above MAX powder in the furnace and inject argon gas for 30 minutes. (At this time, set the gas valve so that the value is between 10 and 11.)

[0210]

[0211] - After 30 minutes, sintering is performed through a furnace.

[0212]

[0213] - To wash the high-conductivity MAX block obtained after sintering, weigh the MAX block and place it in a container dedicated to HCl washing.

[0214] (At this time, add 10 times the weight of the MAX block so that the ratio of DI water: HCl = 1:3, but put the DI water in the container first, and before adding the HCl, put in a large stirrer and rotate it at 300 rpm.)

[0215]

[0216] - After that, slowly pour in HCl and let it react for 48 hours.

[0217]

[0218] - Place the MAX block after the reaction is complete in a 1L centrifuge container, add DI water, and spin at 5000 rpm for 5 minutes.

[0219] - Afterwards, remove everything except the sediment, fill with DI water, and wash through vacuum filtration.

[0220] - While performing vacuum filtration, continue to pour DI water to make the solution neutral.

[0221] (At this time, it is recommended to add about 1000ml of DI water.)

[0222]

[0223] - Once the washing is complete, dry it in the oven for about a day.

[0224]

[0225] - Once drying is complete, the above post-sintering process is repeated once more, but this time, washing is performed for only 24 hours.

[0226]

[0227] - After washing twice, filter through a 75 μm sieve and store in a 70 ml vial.

[0228]

[0229] 2. A layer removal step (etching)

[0230]

[0231] - 2g of LiF and 1g of the MAX structure powder provided above are provided.

[0232]

[0233] - Place a stirring bar in a 60mL etching bottle and set the hot plate to 35°C / 550rpm.

[0234]

[0235] - Add 10 mL of DI water and 10 mL of HCl to the bottle in sequence. (Pay attention to the order).

[0236]

[0237] - Immediately after adding the above HCl, add LiF powder.

[0238]

[0239] - Wait until the above LiF powder is completely melted at 550 rpm.

[0240]

[0241] - After confirming that the above LiF powder is completely dissolved, add MAX powder in small amounts.

[0242]

[0243] - Add the above MAX powder and maintain at 500 rpm for 10 minutes, then lower to 350 rpm and react at room temperature for 24 hours.

[0244]

[0245] 3. MXene layer separation step (Delamination)

[0246]

[0247] - After the above A-layer separation step is completed, the formed MXene solution is transferred to a 1L centrifuge tube and filled with DIW. At this time, DIW is filled so that the total weight of DIW + MXene + bottle is approximately 850 g.

[0248]

[0249] - Fit a holder suitable for a 1L centrifuge tube, place the centrifuge tube in the balancing position, and centrifuge. Centrifuge 6 times (7000 rpm / 5 min *2 times + 7000 rpm / 10 min *4 times).

[0250]

[0251] - In the centrifugation step, discard the acidic solvent (supernatant) that comes out after centrifugation. (It should be colorless.)

[0252]

[0253] - After completely discarding the last acidic solvent from the 1L centrifuge tube, add DI water.

[0254] - Hand shake and voltex until the adhesive on the wall is completely loosened, and after it is completely loosened, transfer it to a conical tube and shake it.

[0255]

[0256] - After shaking, centrifuge the conical tube at 3500 rpm for 5 minutes.

[0257]

[0258] - After the final centrifugation, the suspended solids are collected and used. At this time, the suspended solids are MXene and the sediments are MAX.

[0259]

[0260] - Pour only the suspended solids (MXene) into a new conical tube.

[0261]

[0262] Experimental Example 1. Analysis of electrical characteristics of MXene according to one embodiment of the present invention.

[0263]

[0264] Figure 9 is a graph showing data measuring the electrical conductivity of a high-conductivity MXene according to an embodiment of the present invention in (a) and (b), and (c) is a graph showing data measuring the electrical conductivity of a conventionally disclosed MXene.

[0265] The above experimental example is described with reference to FIGS. 9 and 10.

[0266]

[0267] Referring to (c) and (d) of Fig. 10, the surface of the previously disclosed MXene has surface defects (pores) of 10 nm or larger in size and 1 μm or larger. 2 It can be confirmed that there are more than 100 of them per area.

[0268] On the other hand, referring to (a) and (b) of FIG. 10, it can be confirmed that no visible surface defects (pores) larger than 10 nm are observed on the surface of the high-conductivity MXene according to an example of the above embodiment.

[0269] Since the above surface defect is a problem directly related to the electrical properties of MXene, it can be expected that the MXene according to the example of the above embodiment will show a better effect in electrical properties such as electrical conductivity, as the surface defect is greatly alleviated.

[0270]

[0271] Referring to (a) and (b) of FIG. 9, it can be confirmed that in the case of MXene according to one embodiment of the present invention, the electrical conductivity is formed at an average level of 25,000 S / cm and has a high value of up to 45,000 S / cm.

[0272] On the other hand, referring to (c) of Fig. 9, in the case of MXene previously disclosed in a previous study, it can be confirmed that the electrical conductivity is formed at an average level of 18,000 S / cm and has a maximum value of 25,000 S / cm.

[0273]

[0274] Finally, it can be confirmed that the MXene manufactured according to one embodiment of the present invention has better electrical properties than the MXene disclosed in previous studies.

[0275] These results are consistent with what was predicted previously in Figure 10.

[0276]

[0277] The foregoing description of the present invention is for illustrative purposes only, and those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. For example, each component described as a single entity may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined manner.

[0278] The scope of the present invention is indicated by the claims described below, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention.

Claims

1. Step of having a MAX structure; A step of forming an MXene layer by removing the A layer from the above-mentioned MAX structure; and A step of controlling the thickness and structure by separating (delamination) the MXene layer formed above, A method for manufacturing a high-conductivity MXene, characterized in that the step of forming the MXene layer includes a step of adding the MAX structure provided to a solution containing HCl and LiF and causing a reaction.

2. A method for manufacturing a high-conductivity MXene, characterized in that in the first paragraph, the MAX structure is a structure in which the M element is Ti, the A element is Al, and the X element is C.

3. In the first paragraph, the step of having the MAX structure is as follows: A step of forming MAX powder by ball milling a precursor of a MAX structure; A step of forming a MAX block by sintering the above MAX powder; A step of washing the formed MAX block with strong acid; and A method for manufacturing a high-conductivity MXene, characterized by including a step of neutralizing the MAX block reacted with the strong acid.

4. A method for manufacturing a high-conductivity MXene, characterized in that in the third paragraph, the precursor of the MAX structure is a material containing TiC, Ti, and Al.

5. In the third paragraph, the step of neutralizing the MAX block is: Step of adding distilled water to the above MAX block and centrifuging; A step of washing by adding distilled water to the centrifuged MAX block and filtering under reduced pressure; and A method for manufacturing high-conductivity MXene, characterized by comprising a step of drying the washed MAX block.

6. In the fifth paragraph, the centrifuging step is: A method for manufacturing high-conductivity MXene, characterized in that it is performed at 4000 rpm to 6000 rpm.

7. In the third paragraph, after the step of neutralizing the MAX block, A method for manufacturing high-conductivity MXene, characterized in that the step of washing the above MAX block with a strong acid is repeated once more.

8. In the first paragraph, the step of adding the MAX structure to the solution containing HCl and LiF and causing a reaction is as follows: A step of forming an acidic solution by adding a strong acid to distilled water; After the step of forming the acidic solution, a step of adding LiF powder within 10 seconds; and Including a step of completely dissolving the above LiF powder, A method for manufacturing high-conductivity MXene, characterized in that the LiF powder can be easily dissolved through the heat of reaction between distilled water and a strong acid generated in the step of forming the acidic solution.

9. In the first paragraph, the solution containing HCl and LiF, A method for producing high-conductivity MXene, characterized in that the above HCl and LiF are included in a molar ratio of 1:1 to 2:

1.

10. In the first paragraph, the step of adding the MAX structure to the solution containing HCl and LiF and causing a reaction is as follows: After adding the above MAX structure, a first stirring step at 500 rpm to 600 rpm; and A method for producing high-conductivity MXene, characterized in that it comprises a second stirring step at 300 rpm to 400 rpm after the first stirring step.

11. In the 10th paragraph, the first stirring step is performed for 20 minutes or less, A method for producing high-conductivity MXene, characterized in that the second stirring step is performed for 20 to 30 hours.

12. In the first paragraph, the step of controlling the thickness and structure by separating (delaminating) the MXene layer is as follows: A step of centrifuging the MXene solution containing the formed MXene layer 5 to 10 times; and A method for producing high-conductivity MXene, characterized by comprising a second centrifugation step of separating the precipitate separated through the first centrifugation step.

13. Manufactured according to the high-conductivity MXene manufacturing method of Article 1, The number of defects larger than 10 nm on the surface of the above MXene is 10 / μm 2 High conductivity MXene characterized by the following.

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