阅读说明：本技术 一种MXene二维材料的制备方法及应用 (Preparation method and application of MXene two-dimensional material ) 是由 周双 方俊育 苏耀荣 吕林筱 郭思仪 韩培刚 于 2021-07-27 设计创作，主要内容包括：本发明实施例公开了一种MXene二维材料的制备方法及应用,按照摩尔比1:10～14将Ti3AlC2与NaOH分散于刚玉坩埚中；将坩埚转移到石英玻璃管抽真空并通入氮气,在400℃下反应至少24h,冷却至室温后,将所得样品用去离子水清洗,得到黑灰色液体；将黑灰色液体置于反应釜中,用超声破碎机处理至少20min,得到黑灰色的悬浮液；将悬浮液置于试管中,用离心机在4000r转速下离心,得到下层沉淀,并用去离子水反复清洗,得到灰色沉淀物,将灰色沉淀物进行真空干燥处理,得到二维材料MXene。由于该材料使用NaOH进行刻蚀,故材料表面不会形成不可控的官能团,不会造成污染。(The embodiment of the invention discloses a preparation method and application of an MXene two-dimensional material, wherein Ti3AlC2 and NaOH are dispersed in a corundum crucible according to a molar ratio of 1: 10-14; transferring the crucible to a quartz glass tube, vacuumizing, introducing nitrogen, reacting at 400 ℃ for at least 24 hours, cooling to room temperature, and cleaning the obtained sample with deionized water to obtain a black-gray liquid; putting the black and gray liquid into a reaction kettle, and treating for at least 20min by using an ultrasonic crusher to obtain black and gray suspension; and placing the suspension in a test tube, centrifuging at the rotating speed of 4000r by using a centrifuge to obtain a lower-layer precipitate, repeatedly washing by using deionized water to obtain a gray precipitate, and performing vacuum drying treatment on the gray precipitate to obtain the two-dimensional material MXene. As the material is etched by using NaOH, uncontrollable functional groups cannot be formed on the surface of the material, and pollution cannot be caused.)

1. A preparation method of an MXene two-dimensional material is characterized by comprising the following steps:

ti is added according to a molar ratio of 1: 10-14₃AlC₂Uniformly dispersing the mixture and NaOH in a corundum crucible;

transferring the crucible to a quartz glass tube, vacuumizing, introducing nitrogen, reacting at 400-600 ℃ for at least 24h, cooling to room temperature, and cleaning the obtained sample with deionized water to obtain a black-gray liquid;

placing the obtained black and gray liquid in a reaction kettle, and treating for at least 20min by using an ultrasonic crusher to obtain black and gray suspension;

and placing the suspension in a test tube, centrifuging at the rotating speed of 4000-8000 r by using a centrifugal machine to obtain a lower-layer precipitate, repeatedly cleaning the lower-layer precipitate by using deionized water to obtain a gray precipitate, and performing vacuum drying treatment on the gray precipitate to obtain the two-dimensional material MXene.

2. The method according to claim 1, wherein Ti is added in a molar ratio of 1:12₃AlC₂And NaOH are uniformly dispersed in the corundum crucible.

3. The production method according to claim 1, wherein the crucible is transferred to a quartz glass tube, and after vacuum evacuation and introduction of nitrogen gas, the reaction is carried out at 500 ℃ for 48 hours.

4. The production method according to claim 3, wherein the temperature increase rate is 1 ℃/min.

5. The method according to claim 1, wherein the MXene two-dimensional material has an accordion-layered structure.

6. The method according to claim 1, wherein the obtained liquid is placed in a reaction vessel and treated with an ultrasonic crusher for 30min to obtain a suspension of black and gray

7. The method according to claim 1, wherein the suspension is placed in a test tube and centrifuged at 6000r using a centrifuge.

8. Use of an MXene two-dimensional material according to any one of claims 1 to 8 in the preparation of a supercapacitor or battery.

9. A capacitor comprising the MXene two-dimensional material according to any one of claims 1 to 8.

10. A battery comprising the MXene two-dimensional material according to any one of claims 1 to 8.

Technical Field

The embodiment of the invention relates to the technical field of chemistry, in particular to a preparation method and application of an MXene two-dimensional material.

Background

MXene, a new two-dimensional material, mainly transition metal carbides or nitrides, is generally synthesized by etching A layers in the MAX phase (where M is an early transition metal, A is mainly a group IIIA or group IVA element, and X is C and/or N). MXene, a novel two-dimensional layered material, has excellent metal conductivity and is widely applied to the research and development of supercapacitors at the present stage. In addition to this, MXene sheets have high strain sensitivity and abundant surface functional groups, thus having a hydrophilic surface, which has a positive impact on the development of bioelectronic materials. In summary, MXene, a novel two-dimensional material, has many properties that traditional materials cannot possess, and will play a crucial role in multiple aspects in the future.

In the MAX phase, M-X bonds have a mixed covalent/metal/ionic character, stronger, while M-A is a metallic bond, weaker, so we can remove the A layer chemically without affecting the M-X bonds. For example, removal of the a layer with some etchant or heating MAX under vacuum conditions at high temperature in molten salts or molten metals results in selective loss of the a layer. The traditional MXene synthesis method utilizes HF for etching, and although HF can effectively remove the A layer in the MAX phase, HF is a strong corrosive agent, is harmful to human bodies and can cause serious pollution. And the surface functional group of MXene obtained by HF etching cannot be controlled. In addition, the fluorine ions in HF may reduce the properties of the material, such as conductivity, to some extent. Therefore, a fluorine-free method for synthesizing MXene is urgently needed.

At present, hydrothermal methods or molten metal methods are adopted for synthesizing MXene without fluorine, and the A layer in the MAX phase can be removed, but the methods have some problems, such as insufficient purity of synthesized samples, poor performance in sensitive tests, realization of the method only by high temperature of about one thousand ℃, and the like.

Disclosure of Invention

In order to solve the above technical problem, an embodiment of the present invention provides a method for preparing an MXene two-dimensional material, including:

ti is added according to a molar ratio of 1: 10-14₃AlC₂Uniformly dispersing the mixture and NaOH in a corundum crucible;

transferring the crucible to a quartz glass tube, vacuumizing, introducing nitrogen, reacting at 400-600 ℃ for at least 24h, cooling to room temperature, and cleaning the obtained sample with deionized water to obtain a black-gray liquid;

and (3) placing the obtained black and gray liquid in a reaction kettle, and treating for at least 20min by using an ultrasonic crusher to obtain black and gray suspension.

And placing the suspension in a test tube, centrifuging at the rotating speed of 4000-8000 r by using a centrifugal machine to obtain a lower-layer precipitate, repeatedly cleaning the lower-layer precipitate by using deionized water to obtain a gray precipitate, and performing vacuum drying treatment on the gray precipitate to obtain the two-dimensional material MXene.

Preferably, Ti is added in a molar ratio of 1:12₃AlC₂And NaOH are uniformly dispersed in the corundum crucible.

Preferably, the crucible is transferred to a quartz glass tube, and after vacuum pumping and nitrogen gas introduction, the reaction is carried out at 500 ℃ for 48 hours.

Preferably, the rate of temperature rise is 1 deg.C/min.

Preferably, the MXene two-dimensional material is in an accordion-layered structure.

Preferably, the obtained black-gray liquid is placed in a reaction kettle and treated for 30min by an ultrasonic crusher to obtain a black-gray suspension

Preferably, the suspension is placed in a test tube and centrifuged with a centrifuge at 6000 r.

Use of an MXene two-dimensional material according to any one of claims 1 to 8 in the preparation of a supercapacitor or battery.

A capacitor comprising the MXene two-dimensional material according to any one of claims 1 to 8.

A battery comprising the MXene two-dimensional material according to any one of claims 1 to 8.

The embodiment of the invention has an organ-shaped structure like MXene obtained by traditional HF etching, can enable electrons to rapidly pass through the interlayer, and is a potential material of a super battery or a capacitor. In addition, because NaOH is used for etching, uncontrollable functional groups are not formed on the surface of the material, and the environment is not polluted. In addition, the scheme in the embodiment does not need high temperature, and the MXene can be fully etched by using NaOH, so that the purity of MXene is improved, and the sensitivity of capacitance test can be improved by applying the MXene two-dimensional material to the capacitance or the battery.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a Scanning Electron Microscope (SEM) test chart of an embodiment of the invention;

FIG. 2 is an X-ray diffraction (XRD) test pattern of an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention.

According to one embodiment of the invention, firstly, a certain amount of Ti3AlC2 and NaOH are put into a glove box according to the molar ratio of 1:12, fully ground and mixed in a water-free and oxygen-free environment, and uniformly dispersed in a corundum crucible; then transferring the crucible into a quartz glass tube, vacuumizing and introducing nitrogen, and reacting for 48 hours at 600 ℃ (the heating rate is 1 ℃/min); cooling to room temperature, and then cleaning the obtained sample with deionized water to obtain a black and gray liquid; and (3) placing the obtained black and gray liquid in a reaction kettle, and treating for 30min by using an ultrasonic crusher to obtain black and gray suspension. Placing the suspension in a test tube, centrifuging at 6000r to obtain lower precipitate, and repeatedly washing the lower precipitate with deionized water to obtain gray precipitate. And finally, carrying out vacuum drying treatment on the gray precipitate to obtain the product MXene two-dimensional material.

Example of the invention, FIG. 1a shows a starting material Ti₃AlC₂SEM image of (d). As can be seen from FIG. 1a, under an electron microscope, the starting material Ti₃AlC₂Is a block structure, and has no positive influence on the transmission of electrons/ions.

FIGS. 1b-d are SEM images of MXene synthesized in the experiment. As can be seen from the figures b-d, under electron microscopy MXene prepared from molten NaOH has a distinct layered structure, similar to an accordion, which is unexpected for the starting material Ti₃AlC₂The middle layer A, namely the aluminum layer, is successfully corroded to form the layered structure which is favorable for the transmission of electrons/ions in the middle of the layered structure, and the success of the experiment is visually illustrated by the three SEM pictures b-d, namely the layer A of the raw material is successfully removed to prepare the MXene novel two-dimensional material.

FIG. 2 shows a raw material Ti₃AlC₂Images were compared to xrd for Ti3C2 synthesized MXene. As can be seen from FIG. 2, MXene Ti3C2 synthesized from molten NaOH and the starting material Ti₃AlC₂The curve of (A) xrd is very different, Ti₃C₂The diffraction line (i.e., about 39 ℃ diffraction line) of (104) plane of (A) is compared with that of Ti₃AlC₂The strength was significantly reduced, indicating that Ti was removed by high frequency etching after the aluminum layer was removed₃AlC₂Conversion to Ti₃C₂. Further, it was found that, due to the increase in interlayer spacing of Ti3C2, Ti was delaminated by NaOH etching₃C₂The diffraction peak at 9.5 ° shifted to around 9.4 ° to a lower angle, indicating Ti₃C₂Successful peeling.

The foregoing is only a partial embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.