CN114180970A

CN114180970A - Nitrogen-containing medium-entropy or high-entropy MAX phase material and preparation method and application thereof

Info

Publication number: CN114180970A
Application number: CN202210053781.5A
Authority: CN
Inventors: 杨树斌; 杜志国
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2021-05-21
Filing date: 2022-01-18
Publication date: 2022-03-15
Anticipated expiration: 2042-01-18
Also published as: CN114180970B; CN116463536A; CN113149659A

Abstract

The invention discloses a preparation method of a nitrogen-containing medium-entropy or high-entropy MAX phase material and a two-dimensional material, which comprises the following steps: at least one nitrogen-containing MAX phase and a plurality of nitrogen-free MAX phases are used as raw materials for reaction; wherein the sum of the element types of M in the MAX phase is more than four, so as to obtain the nitrogen-containing medium-entropy or high-entropy MAX phase material; or at least one nitrogen-containing MAX phase, a plurality of transition metal simple substances or compounds and A simple substances or compounds are used as raw materials to react, the sum of the element types of M and the element types of a plurality of transition metals in the MAX phase is more than four, and the nitrogen-containing MAX phase material with medium entropy or high entropy is prepared. The method has simple process, is easy for industrial amplification production, and lays a foundation for the application of nitrogen-containing medium-entropy or high-entropy MAX phase materials and two-dimensional materials.

Description

Nitrogen-containing medium-entropy or high-entropy MAX phase material and preparation method and application thereof

The present application claims priority of chinese patent application with application number 202110560272.7 entitled "nitrogen-containing mid-entropy or high-entropy MAX phase material and method of making and using the same" filed from chinese patent office on 21/5/2021, the contents of which are incorporated herein by reference.

Technical Field

The invention relates to the field of new materials, in particular to a nitrogen-containing medium-entropy or high-entropy MAX phase material, a preparation method and application thereof, and a preparation method of the high-entropy MAX phase material.

Background

The layered transition metal carbides, nitrides and carbonitrides (MAX phases) have a rich chemical composition, of the formula M_n+1AX_nM represents an early transition metal element such as Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, etc., A is mainly a group 13-16 element such as Al, Si, P, S, etc., and X represents a C and/or N element. The MAX phase material is also called a conductive ceramic because the strong coupling between the 3d orbital of the M metal atom and the 2p orbital of the a atom imparts electrical conductivity to the MAX phase metal and thermal conductivity to the ceramic. To date, over 150 species of MAX phase materials have been discovered, but the nitrogen-containing MAX phase is concentrated only in Ti₂AlN、Ti₂AlC_xN_1-x、Ti₃AlCN and Ti₄AlN₃Very few, nitrogen-containing, high entropy MAX phases (containing at least 5 transition metal elements) have not been reported to date. Accordingly, a high-entropy two-dimensional material containing nitrogen is still not obtained. The reported nitrogen-containing high-entropy materials mainly focus on rock salt structure (Cr)_0.2Mo_0.2Nb_0.2V_0.2Zr_0.2) N and (V)_0.2Nb_0.2Ta_0.2Mo_0.2W_0.2) N and the like, and has a three-dimensional block structure, and the high-entropy nitride has excellent mechanical, magnetic, high-temperature-resistant and corrosion-resistant properties. Therefore, it is presumed that the nitrogen-containing high-entropy two-dimensional material tends to exhibit more excellent physicochemical properties. Therefore, the development of nitrogen-containing high-entropy two-dimensional material, nitrogen-containing high-entropy MAX phase material and preparation method thereof are urgently neededThe method is carried out.

Currently, the common method for preparing MAX phase materials in the prior art is a high temperature sintering process comprising the steps of: (1) mixing elementary substance powder forming MAX phase according to a proportion; (2) putting the powder mixture into an agate ball milling tank, and ball milling for a plurality of hours by using a ball mill; (3) and putting the mixed powder subjected to ball milling into an alumina crucible, and placing the alumina crucible into a tubular furnace for high-temperature sintering under the protection of argon. (4) And after the reaction is finished, cooling to room temperature, taking out the sample, grinding and sieving to obtain MAX phase powder. However, in the method, when the nitrogen-containing MAX phase material containing multiple transition metal elements is prepared, more than four transition metal simple substances are added, and the transition metal simple substances are easy to react with the nitrogen-containing raw materials under a high-temperature environment to generate transition metal nitride particles with a rock salt structure, so that the homogeneous medium-entropy or high-entropy MAX phase material cannot be prepared.

Disclosure of Invention

The invention provides a preparation method of a nitrogen-containing medium-entropy or high-entropy MAX phase material, aiming at the technical problem that a high-temperature sintering method in the prior art is difficult to prepare the homogeneous nitrogen-containing medium-entropy or high-entropy MAX phase material, and the preparation method comprises the following steps: at least one nitrogen-containing MAX phase and a plurality of nitrogen-free MAX phases are used as raw materials for reaction; the sum of the element types of M in the MAX phase is more than four, and the nitrogen-containing MAX phase material with medium entropy or high entropy is prepared; or at least one nitrogen-containing MAX phase, a plurality of transition metal simple substances or compounds and A simple substances or compounds are used as raw materials to react, the sum of the element types of M in the MAX phase and the element types of the plurality of transition metals is more than four, and the nitrogen-containing MAX phase material with medium entropy or high entropy is prepared.

In some embodiments, the nitrogen-containing medium-entropy or high-entropy MAX phase material obtained is one in which M is selected from at least four metal elements from groups IIIB, IVB, VB, VIB, VIIB, VIII, IB, IIB; a is selected from at least one of VIIB, VIII, IB, IIB, IIIA, IVA, VA and VIA group elements; the X element is nitrogen element and at least one nonmetal element in IIIA, IVA, VA and VIA.

In some embodiments, in the nitrogen-containing MAX phase, X is carbon and nitrogen; and/or, said M or said transition metal is selected from elements of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Pt, Au, Ag, Pd, Cu or Bi; and/or the compound of the transition metal is a carbide of the transition metal; and/or A is selected from Al, Si, P, S, Fe, Cu, Zn, Ga, Ge, As, Cd, In, Sn, Tl, Pb or Bi elements.

In some embodiments, prior to performing the reaction, further comprising: grinding: grinding the raw materials; and/or, a pressing step: pressing the raw materials to form the composite material; preferably, the pressurization pressure is between 10MPa and 50 MPa.

In some embodiments, the temperature of the reaction is between 600 ℃ to 3000 ℃; preferably, between 1000 ℃ and 1700 ℃; and/or the reaction time is between 1h and 20 h.

In some embodiments, the nitrogen-containing medium-or high-entropy MAX phase material produced has an atomic ratio C: N of (1-x): x, where (0< x < 1); and/or the element types of M in the prepared nitrogen-containing medium-entropy or high-entropy MAX phase material are four, five or six.

The invention also provides a preparation method of the nitrogen-containing medium-entropy or high-entropy two-dimensional material, which comprises the following steps: and reacting the nitrogen-containing medium-entropy or high-entropy MAX phase material obtained by the preparation method with an etching agent to etch the component A in the nitrogen-containing medium-entropy or high-entropy MAX phase material to obtain the nitrogen-containing medium-entropy or high-entropy two-dimensional material.

In some embodiments, the etchant is one or more of a simple halogen, a halogen hydride, or a nitrogen hydride; or the etchant is a hydrogen halide solution, an acid solution + halide salt system, or a halogen metal salt.

In some embodiments, the reaction is a vapor phase etch, the etchant is in the vapor phase, or is capable of being converted to the vapor phase for etching; and/or the thickness of the obtained nitrogen-containing medium-entropy or high-entropy two-dimensional material is between 2nm and 10 nm.

The invention also discloses an application of the nitrogen-containing medium-entropy or high-entropy AMX phase material obtained by the preparation method, or a nitrogen-containing medium-entropy or high-entropy two-dimensional material in catalysis, sensors, electronic devices, supercapacitors, batteries, electromagnetic shielding, wave-absorbing materials, corrosion-resistant materials or superconducting materials.

According to the preparation method of the MAX-phase material with entropy or high entropy, at least one MAX-phase containing nitrogen is used as a framework, so that the technical problem that the MAX-phase material with intermediate entropy or high entropy containing nitrogen cannot be synthesized due to reaction between a transition metal element and a nitrogen-containing raw material in a high-temperature sintering reaction is solved, the novel MAX-phase material with intermediate entropy or high entropy containing nitrogen is prepared, the variety of the MAX-phase material family is expanded, and a new thought is provided for the preparation of the MAX-phase material with intermediate entropy or high entropy. The novel nitrogen-containing medium-entropy or high-entropy MAX phase material is prepared on the basis of the preparation method, the A in the material is etched by the etching agent, and a novel nitrogen-containing medium-entropy or high-entropy two-dimensional material (nitrogen-containing MXene material) is obtained, so that a new variety is added to a two-dimensional material family.

The preparation method disclosed by the invention is simple in process and easy for industrial amplification production, lays a foundation for the application of the nitrogen-containing medium-entropy or high-entropy MAX phase material and the two-dimensional material, and has a wide application prospect in the fields of catalysis, sensors, electronic devices, supercapacitors, batteries, electromagnetic shielding, wave-absorbing materials, corrosion-resistant materials, superconducting materials and the like in the future.

Drawings

FIG. 1 Nitrogen-containing high entropy MAX phase Material (Ti) in example 1 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5(a) And nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_x(b) SEM photograph of (a);

FIG. 2 shows a nitrogen-containing high-entropy MAX phase material (Ti) in example 1 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5And nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xComparing the XRD spectrogram;

FIG. 3A nitrogen-containing high-entropy two-dimensional Material (Ti) in example 1 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xTEM, HRTEM, STEM photographs and primitive profiles of;

FIG. 4A nitrogen-containing high-entropy two-dimensional material (Ti) in example 1 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xAFM photograph (a) and thickness analysis chart (b);

FIG. 5 shows a nitrogen-containing high-entropy MAX phase material (Ti) in example 2 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5(a) And nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_x(b) SEM photograph of (a);

FIG. 6 shows a nitrogen-containing high-entropy MAX phase material (Ti) in example 2 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5And nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xComparing the XRD spectrogram;

FIG. 7 Nitrogen-containing high-entropy two-dimensional Material (Ti) in example 2 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xTEM, HRTEM, STEM photographs and primitive profiles of;

FIG. 8A nitrogen-containing high-entropy two-dimensional material (Ti) in example 2 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xAFM photograph (a) and thickness analysis chart (b);

FIG. 9 shows a nitrogen-containing high-entropy MAX-phase material (Ti) in example 3 of the present invention_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5SEM photograph of (a);

FIG. 10 shows nitrogen in example 3 of the present inventionHigh entropy MAX phase materials (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5XRD spectrum of (1);

FIG. 11A nitrogen-containing high-entropy two-dimensional material (Ti) in example 4 of the present invention_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2SEM photograph of (a);

FIG. 12 shows a nitrogen-containing high-entropy MAX phase material (Ti) in example 4 of the present invention_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2XRD spectrum of (1);

FIG. 13 shows a nitrogen-containing high-entropy MAX-phase material (Ti) in example 5 of the present invention_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2SEM photograph of (a);

FIG. 14 shows a nitrogen-containing high-entropy MAX-phase material (Ti) in example 5 of the present invention_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2XRD spectrum of (1);

FIG. 15A nitrogen-containing high-entropy two-dimensional material (Ti) in example 6 of the present invention_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂C_0.8N_0.2T_xSEM photograph of (a);

FIG. 16A nitrogen-containing high-entropy two-dimensional material (Ti) in example 6 of the present invention_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂C_0.8N_0.2T_xTEM and HRTEM;

FIG. 17 Nitrogen-containing Medium entropy MAX phase Material (Ti) in example 7 of the present invention_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5Has nitrogen-containing medium entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xSEM photograph of (a);

FIG. 18 Nitrogen-containing Medium entropy MAX phase Material (Ti) in example 7 of the present invention_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5Has nitrogen-containing medium entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xComparing XRD patterns of the two parts;

FIG. 19 Nitrogen-containing mid-entropy two-dimensional Material (Ti) in example 7 of the present invention_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xTEM, HRTEM, STEM photographs and primitive profiles of;

FIG. 20 Nitrogen-containing Medium entropy MAX phase Material (Ti) in example 8 of the present invention_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5Has nitrogen-containing medium entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5T_xSEM photograph of (a);

FIG. 21 Nitrogen-containing Medium entropy MAX phase Material (Ti) in example 8 of the present invention_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5Has nitrogen-containing medium entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5T_xComparing XRD patterns of the two parts;

FIG. 22 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in example 21 of the present invention;

FIG. 23 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in example 22 of the present invention;

FIG. 24 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in example 23 of the present invention;

FIG. 25 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in accordance with example 24 of the present invention;

FIG. 26 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in accordance with example 25 of the present invention;

FIG. 27 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in example 26 of the present invention;

FIG. 28 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in example 27 of the present invention;

FIG. 29 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in example 28 of the present invention;

FIG. 30 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in example 29 of the present invention;

FIG. 31 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in accordance with example 30 of the present invention;

FIG. 32 is an (a) XRD spectrum (b) SEM image of high entropy MAX phase material in accordance with example 31 of the present invention;

FIG. 33 is an XRD spectrum (a) and SEM image (b) of the high entropy MAX phase material of example 32 of the present invention.

Detailed Description

The following detailed description of the present invention is provided in conjunction with the accompanying drawings, but it should be understood that the scope of the present invention is not limited to the specific embodiments.

Throughout the specification and claims, unless explicitly stated otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to imply the inclusion of a stated element or component but not the exclusion of any other element or component.

The technical solution of the present invention will be described below by way of specific examples. It is to be understood that one or more of the steps mentioned in the present invention does not exclude the presence of other methods or steps before or after the combined steps, or that other methods or steps may be inserted between the explicitly mentioned steps. It should also be understood that these examples are intended only to illustrate the invention and are not intended to limit the scope of the invention. Unless otherwise indicated, the numbering of the method steps is only for the purpose of identifying the method steps, and is not intended to limit the arrangement order of each method or the scope of the implementation of the present invention, and changes or modifications of the relative relationship thereof may be regarded as the scope of the implementation of the present invention without substantial technical change.

The raw materials and apparatuses used in the examples are not particularly limited in their sources, and may be purchased from the market or prepared according to a conventional method well known to those skilled in the art.

The technical idea of the invention is that in the preparation method of the nitrogen-containing medium-entropy or high-entropy MAX phase material, at least one nitrogen-containing MAX phase material is used as a reaction raw material, and the nitrogen-containing MAX phase material is used as a framework, so that a transition metal element in the MAX phase material diffuses into the nitrogen-containing MAX phase material framework under the condition of high temperature, or a transition metal element in a simple substance or carbide of the transition metal diffuses into the nitrogen-containing MAX phase material framework, and the novel nitrogen-containing MAX phase material with M being more than four metal elements is obtained. Referring to the definition of various metal alloy elements in the material science, in the present application, when M is three or four metal elements, it is called a medium-entropy MAX-phase material, and when M is five or more metal elements, it is called a high-entropy MAX-phase material.

The invention specifically comprises two technical implementation modes:

taking at least one nitrogen-containing MAX phase and several nitrogen-free MAX phases as raw materials to react, wherein the sum of the element types of M in the MAX phases is more than four, and because the reaction raw materials and MAX material crystals belong to MAX material crystals, carrying out isomorphous replacement reaction under the condition of high temperature, different types of MAX phase materials are mutually fused into a uniform phase, and meanwhile, different types of M are diffused and fused in the MAX phase, and finally obtaining the nitrogen-containing MAX phase material with medium entropy or high entropy;

and (II) at least one nitrogen-containing MAX phase, a plurality of transition metal simple substances or compounds and A simple substances or compounds are used as raw materials to react, the sum of the element types of M in the MAX phase and the element types of the transition metals is more than four, the nitrogen-containing MAX phase is used as a framework material under the condition of high temperature, and the transition metal elements and A can diffuse into the nitrogen-containing MAX phase material, so that the nitrogen-containing medium-entropy or high-entropy MAX phase material is obtained.

The technical features of the present invention will be described below with reference to specific examples.

Example 1

This example is to prepare a nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5And obtaining a nitrogen-containing high-entropy two-dimensional material (Ti) by etching Al element in the material_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5The technical features of the present invention are explained for the purpose of example.

Nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5The preparation of (1) comprises:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5In the (molar ratio) of Ti₄AlN₃、V₂AlC and (Nb)_1/3Ta_1/3Zr_1/3)₂AlC is used as a raw material precursor, and the molar ratio of the AlC to the raw material precursor is Ti₄AlN₃:V₂AlC:(Nb_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio when AlC is 1:1: 3;

grinding: putting the raw materials into a mortar for manual grinding for 10min, and after grinding, putting the mixed powder into a powder tabletting mold for cold pressing treatment under the pressure of 20MPa for 5 min;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/ ₆Zr_1/6V_1/6)₂AlC_0.5N_0.5And (3) powder.

Nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5The preparation of (1) comprises:

etching: 40ml of concentrated hydrochloric acid and 2g of LiF were mixed uniformly to obtain an etchant, and 1g of the nitrogen-containing high-entropy MAX phase (Ti) obtained in step (1) in this example was used_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Placing the mixture into an etching agent, reacting for 24 hours at 50 ℃, and after the reaction is finished, performing centrifugal separation, water washing and drying treatment to obtain the nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/ ₆Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_x(wherein T is_xRepresents a functional group contained).

For nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5And a nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_x(Nitrogen-containing high-entropy MXene) is respectively subjected to Scanning Electron Microscope (SEM) tests, and the results are shown in figures 1a and b, and (Ti) can be seen by comparison_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Has irregular three-dimensional block structure and contains nitrogen and is a high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe shape of the nano-film is an ultrathin, transparent and soft large-area two-dimensional nano-sheet, which shows that the nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5The Al layer in the alloy is effectively etched and removed under the action of hydrochloric acid and LiF etchant, and the corresponding nitrogen-containing high-entropy two-dimensional material (nitrogen-containing high-entropy MXene) is obtained after the reaction is finished. For nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5And high entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe results of X-ray diffraction (XRD) analysis of each sample are shown in FIG. 2, in which the starting material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5The (002) peak in (1) appears at the 12.3 ℃ position and reacts with hydrochloric acidThe (002) peak of the nitrogen-containing high-entropy two-dimensional material product after the reaction of the + LiF etching agent is shifted to 6.7 degrees towards a low angle, and other diffraction peaks corresponding to the nitrogen-containing high-entropy MAX phase disappear, which indicates that the product is completely etched under the action of the hydrochloric acid + LiF etching agent (Ti and LiF etching agent)_1/3Nb_1/6Ta_1/ ₆Zr_1/6V_1/6)₂AlC_0.5N_0.5Al element in the film generates nitrogen-containing high-entropy MXene (Ti) with a lamellar structure_1/3Nb_1/6Ta_1/6Zr_1/ ₆V_1/6)₂C_0.5N_0.5T_xThe interlayer spacing is significantly increased, which is in accordance with (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe results of the scanning electron micrographs are consistent, and the comparison of the XRD spectrogram can also show that the synthesized nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/ ₆Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Diffraction pattern of (A) and reported quaternary MAX phase Ti₂AlC_0.5N_0.5Consistent with no other impurity peaks of carbides and nitrides, indicating the resulting nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Is a single phase, (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe high resolution transmission electron microscopy HRTEM picture and the electron diffraction spectrogram are shown in figures 3a and b, which show that the obtained nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xA rock salt crystal structure having an ultra-thin single crystalline phase. (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xScanning Transmission Electron Microscope (STEM) and atomic distribution diagram results show (FIG. 3C-k), the ultrathin two-dimensional nanosheet has uniform Ti, Nb, Ta, Zr, V, C, N, O and F element distributionThe target product obtained is stated to be (Ti) containing O and F functional groups and containing the element N_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xHigh entropy two dimensional material (nitrogen containing high entropy MXene). The nitrogen-containing high-entropy two-dimensional material (Ti) prepared in this example was tested by Atomic Force Microscopy (AFM) as shown in FIGS. 4a and 4b_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xAbout 2nm, indicating (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xHas the structural characteristics of ultra-thin and soft.

Example 2

This example prepares a nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5And preparing a high-entropy two-dimensional material (Ti) by etching Al element in the material_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5The method comprises the following steps:

the material preparation step: according to the chemical formula (Ti) of the nitrogen-containing high-entropy MAX phase_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₄AlN₃，Nb₂AlC and (V)_1/3Ta_1/3Zr_1/3)₂AlC is used as a raw material precursor, and the molar ratio of the AlC to the raw material precursor is Ti₄AlN₃:Nb₂AlC:(V_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio when AlC is 1:1: 3;

etching: 50ml of 48% hydrofluoric acid (HF) was used as an etchant, and 1g of the nitrogen-containing high-entropy MAX phase (Ti) obtained in this example was used_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Placing the mixture into an etching agent, reacting for 48 hours at 50 ℃, and after the reaction is finished, performing centrifugal separation, water washing and drying treatment to obtain the nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_x(wherein T is_xRepresents a functional group contained).

For nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5And a nitrogen-containing high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_x(Nitrogen-containing high-entropy MXene) is respectively subjected to Scanning Electron Microscope (SEM) tests, and the results are shown in FIGS. 5a and b, and (Ti) can be seen by comparison_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Has irregular three-dimensional block structure and contains nitrogen and is a high-entropy two-dimensional material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xExpanded accordion structure, indicating a nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5The Al layer in the alloy is effectively etched and removed under the action of HF etchant, and the corresponding nitrogen-containing high-entropy two-dimensional material (nitrogen-containing high-entropy MXene) is obtained after the reaction is finished. For nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5And high entropy two-dimensional material (Ti) of accordion_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe results of X-ray diffraction (XRD) analysis of each sample are shown in FIG. 6, in which the starting material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5The (002) peak appears at the position of 12.8 degrees, the (002) peak of the nitrogenous high-entropy two-dimensional material product after the reaction with the HF etchant deviates to 6.8 degrees towards a low angle, and other diffraction peaks corresponding to the nitrogenous high-entropy MAX phase disappear, which indicates that the product is completely etched under the action of the HF etchant (Ti and the like)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Al element in the aluminum alloy generates nitrogen-containing high-entropy MXene (Ti) of accordion_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe interlayer spacing is significantly increased, which is in accordance with (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe shapes of the expanded accordion are consistent, and the synthesized nitrogen-containing high-entropy MAX phase (Ti) can be seen by comparing XRD spectrograms_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Diffraction pattern of (A) and reported quaternary MAX phase Ti₂AlC_0.5N_0.5Consistent with no impurity peaks of other carbides and nitrides, indicateTo a nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Is a single phase, (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe high resolution transmission electron microscope HRTEM picture and the electron diffraction spectrogram (figures 7a and b) show that the obtained nitrogen-containing high-entropy two-dimensional material has an ultrathin two-dimensional atomic layer structure, and the crystal structure of the nitrogen-containing high-entropy two-dimensional material is a single-crystal rock salt crystal structure. (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xThe Scanning Transmission Electron Micrograph (STEM) and the atomic distribution diagram result show that the ultrathin two-dimensional nanosheet has uniform Ti, Nb, Ta, Zr, V, C, N, O and F element distribution (FIG. 7C-k), and the obtained target product is the product containing O and F functional groups and containing N elements (Ti_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xHigh entropy two dimensional material (nitrogen containing high entropy MXene). The nitrogen-containing high-entropy two-dimensional material (Ti) prepared in this example was tested by Atomic Force Microscope (AFM) as shown in FIGS. 8a and b_1/3Nb_1/ ₆Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xAbout 2.0nm, indicating (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂C_0.5N_0.5T_xHas the structural characteristics of ultra-thin and soft.

Example 3

The invention provides another method for preparing nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.4N_0.6In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₄AlN₃、Nb₂AlC、Ta₂AlC、V₂AlC, ZrC and Al are used as raw material precursors, and the molar ratio of the AlC, the ZrC and the Al is Ti₄AlN₃:Nb₂AlC:Ta₂AlC:V₂ZrC and Al are 1:1:1:1:2:3.2, and each raw material precursor is accurately weighed according to the corresponding molar ratio;

For nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Scanning Electron Microscopy (SEM) testing was performed, and the results are shown in FIG. 9, (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Has an irregular three-dimensional block structure, similar to the shape of the MAX phase prepared by most. For nitrogen-containing high-entropy MAX phase material (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5The X-ray diffraction (XRD) analysis showed that the raw material (Ti) was as shown in FIG. 10_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5A strong diffraction peak appears in a middle XRD pattern, and a (002) peak appears at a position of 12.9 degrees, which shows that the material has a layered structure, and a synthesized nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5Diffraction pattern of (A) and reported quaternary MAX phase Ti₂AlC_0.5N_0.5Consistent, indicates that a nitrogen-containing high-entropy MAX phase (Ti) is successfully obtained_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.5N_0.5。

Example 4

The invention provides a method for preparing nitrogen-containing high-entropy MAX phase (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₂AlN，V₂AlC and (Nb)_1/3Ta_1/3Zr_1/3)₂AlC is used as a raw material precursor, and the molar ratio of the AlC to the raw material precursor is Ti₂AlN:V₂AlC:(Nb_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio when AlC is 1:1: 3;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2And (3) powder.

For nitrogen-containing high-entropy MAX phase material (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2Scanning Electron Microscopy (SEM) testing was performed, and the results are shown in FIG. 11, (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2Three-dimensional with irregularitiesBulk structure, similar to most prepared MAX phase morphologies. For nitrogen-containing high-entropy MAX phase material (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2The X-ray diffraction (XRD) analysis showed that the raw material (Ti) was as shown in FIG. 12_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2A strong diffraction peak appears in a middle XRD pattern, and a (002) peak appears at a position of 12.8 degrees, which shows that the material has a layered structure, and a synthesized nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.4N_0.6Diffraction pattern of (A) and reported quaternary MAX phase Ti₂AlC_0.5N_0.5Consistent with no other impurity peaks of carbides and nitrides, indicating the resulting nitrogen-containing high-entropy MAX phase (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2Is a single phase of high purity.

Example 5

The invention provides another method for preparing nitrogen-containing high-entropy MAX phase (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₂AlN，Nb₂AlC and (V)_1/3Ta_1/3Zr_1/3)₂AlC is used as a raw material precursor, and the molar ratio of the AlC to the raw material precursor is Ti₂AlN:Nb₂AlC:(V_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio when AlC is 1:1: 3;

For nitrogen-containing high-entropy MAX phase material (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2Scanning Electron Microscopy (SEM) testing was performed, and the results are shown in FIG. 13, (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2Has an irregular three-dimensional block structure, similar to the shape of the MAX phase prepared by most. For nitrogen-containing high-entropy MAX phase material (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2The X-ray diffraction (XRD) analysis showed that the raw material (Ti) was as shown in FIG. 14_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2A strong diffraction peak appears in a middle XRD pattern, and a (002) peak appears at a position of 12.5 degrees, which shows that the material has a layered structure, and a synthesized nitrogen-containing high-entropy MAX phase (Ti)_1/3Nb_1/6Ta_1/6Zr_1/6V_1/6)₂AlC_0.4N_0.6Diffraction pattern of (A) and reported quaternary MAX phase Ti₂AlC_0.5N_0.5Consistent with no other impurity peaks of carbides and nitrides, indicating the resulting nitrogen-containing high-entropy MAX phase (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2Is a single phase of high purity.

Example 6

This example provides a specific example of a vapor phase method for etching nitrogen-containing high-entropy MAX to prepare a high-entropy two-dimensional material, and uses the nitrogen-containing high-entropy MAX phase (Ti) prepared in example 5_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2Taking HI gas as an etching agent to react and prepare a two-dimensional material as a precursor, wherein the reactor is a tubular furnace and comprises the following steps:

1) placing powdered (Ti) in the tube furnace_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2；

2) Introducing HI gas into the tubular furnace for a period of time, and sealing the reaction cavity after the reaction cavity in the reaction device is filled with the HI gas;

3) heating the interior of the reaction device to 700 ℃, preserving heat for 30min, and carrying out etching reaction to obtain a target product high-entropy two-dimensional material (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂C_0.8N_0.2T_x。

And after the reaction device is naturally cooled to the room temperature, taking out the target product. To (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2High entropy two dimensional material (Ti) after reaction with HI_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂C_0.8N_0.2T_xSEM tests are carried out on the two target products, the results are shown in FIG. 15, the target product after reaction is in an accordion layered structure, and the accordion structure is formed by stacking ultrathin two-dimensional nanosheets layer by layer, which is obviously different from the raw material (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2The lamellar bulk morphology (FIG. 13). This indicates that the HI gas etched in the gas phase reaction (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂AlC_0.8N_0.2Al element in the medium to generate a high-entropy two-dimensional material (Ti) with a lamellar structure_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂C_0.8N_0.2T_xResulting in an enlargement of the interlayer spacing. TargetHigh entropy two-dimensional material (Ti) of product_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂C_0.8N_0.2T_xThe TEM image of (A) has a large number of two-dimensional ultrathin nanosheets, as shown in FIG. 16, indicating that the nanosheets are accordion-like (Ti)_0.2Nb_0.2Ta_0.2Zr_0.2V_0.2)₂C_0.8N_0.2T_xA large number of two-dimensional nanosheets and having a good single crystal structure can be obtained by simple exfoliation.

In this embodiment, a gas-phase etchant HI gas is used, wherein the HI may be replaced by one or more of other halogen simple substances, halogen hydrides, or nitrogen hydrides, such as: br₂、I₂、HBr、NH₃Or pH₃And the like. In the etching process, the gas-phase etchant can enter into the etched MAX phase gaps to more fully etch the phase A, so that the high-entropy two-dimensional material sheet layer (2 nm-10 nm) with the ultrathin structure is obtained. In addition, as the gas phase method etching does not contain solid impurities and can directly obtain the powder material of the high-entropy two-dimensional lamellar, the complex processes of purification, drying and the like of liquid phase etching are avoided, the industrialized batch preparation can be realized, the preparation cost of the high-entropy two-dimensional lamellar material can be reduced, and the method has great commercial value.

Example 7

The invention provides another method for preparing nitrogen-containing medium entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₄AlN₃And (Nb)_1/3Ta_1/3Zr_1/3)₂AlC is used as a raw material precursor, and the molar ratio of the AlC to the raw material precursor is Ti₄AlN₃:(Nb_1/ ₃Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio, wherein AlC is 1: 3;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5And (3) powder.

Nitrogen-containing medium entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5The preparation of (1) comprises:

etching: 40ml of concentrated hydrochloric acid and 2g of LiF were mixed uniformly to obtain an etchant, and 1g of the nitrogen-containing intermediate entropy MAX phase (Ti) obtained in the step (1) of this example was used_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5Placing the mixture into an etching agent, reacting for 24 hours at 50 ℃, and after the reaction is finished, performing centrifugal separation, water washing and drying treatment to obtain the nitrogen-containing intermediate-entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_x(wherein T is_xRepresents a functional group contained).

For nitrogen-containing medium entropy MAX phase material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5And a nitrogen-containing mid-entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_x(Nitrogen-containing mid-entropy MXene) was subjected to Scanning Electron Microscope (SEM) tests, and the results are shown in FIGS. 17a and b, as can be seen by comparison, (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5Has irregular three-dimensional block structure and contains nitrogen-containing medium-entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xHas an ultrathin two-dimensional structure, and shows a nitrogen-containing medium-entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5The Al layer is effectively etched and removed under the action of HF etchant, and the corresponding nitrogen-containing mid-entropy two-dimensional material (nitrogen-containing mid-entropy MXene) is obtained after the reaction is finished. For nitrogen-containing medium entropy MAX phase material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5And a nitrogen-containing mid-entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xThe results of X-ray diffraction (XRD) analysis of each sample are shown in FIG. 18, in which the starting material (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5The (002) peak appears at the position of 12.6 degrees, while the (002) peak of the nitrogen-containing mid-entropy two-dimensional material product after reaction with the etching agent shifts to 6.5 degrees towards a low angle, and other diffraction peaks corresponding to the nitrogen-containing mid-entropy MAX phase disappear, which indicates that the etching agent is completely used for etching (Ti and Ti are fully used for etching)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5Al element in the alloy generates ultrathin two-dimensional nitrogen-containing mid-entropy MXene (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xThe interlayer spacing is significantly increased, which is in accordance with (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xThe ultra-thin two-dimensional shapes are consistent, and the synthesized nitrogen-containing medium entropy MAX phase (Ti) can be seen by comparing XRD spectrograms_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5Diffraction pattern of (A) and reported quaternary MAX phase Ti₂AlC_0.5N_0.5Consistent with no other impurity peaks of carbides and nitrides, indicating the resulting nitrogen-containing mid-entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5Is a single phase, (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xThe high resolution transmission electron microscope HRTEM picture and the electron diffraction spectrogram (figures 19a and b) show that the obtained nitrogen-containing intermediate entropy two-dimensional material has an ultrathin two-dimensional atomic layer structure, and the crystal structure of the nitrogen-containing intermediate entropy two-dimensional material is a single-crystal rock salt crystal structure. (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xThe Scanning Transmission Electron Micrograph (STEM) and the atomic distribution diagram result show that the ultrathin two-dimensional nanosheet has uniform Ti, Ta, Zr, Nb, C, N, O and F element distribution (FIG. 19C-k), and the obtained target product is the product containing O and F functional groups and containing N element (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂C_0.5N_0.5T_xMedium entropy two-dimensional material (nitrogen-containing medium entropy MXene).

Example 8

the material preparation step: according to the formula of the medium entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₄AlN₃And (V)_1/3Ta_1/3Zr_1/3)₂AlC is used as a raw material precursor, and the molar ratio of the AlC to the raw material precursor is Ti₄AlN₃:(V_1/ ₃Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio, wherein AlC is 1: 3;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, grindingGrinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5And (3) powder.

Nitrogen-containing medium entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5The preparation of (1) comprises:

etching: 40ml of concentrated hydrochloric acid and 2g of LiF were mixed uniformly to obtain an etchant, and 1g of the nitrogen-containing medium entropy MAX phase (Ti) obtained in this example was used_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5Placing the mixture into an etching agent, reacting for 24 hours at 50 ℃, and after the reaction is finished, performing centrifugal separation, water washing and drying treatment to obtain the nitrogen-containing intermediate-entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5T_x(wherein T is_xRepresents a functional group contained).

For nitrogen-containing medium entropy MAX phase material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5And a nitrogen-containing mid-entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5T_x(Nitrogen-containing mid-entropy MXene) was subjected to Scanning Electron Microscope (SEM) tests, and the results are shown in FIGS. 20a and b, as can be seen by comparison, (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5Has irregular three-dimensional block structure and contains nitrogen-containing medium-entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5T_xHas an ultrathin two-dimensional structure, and shows a nitrogen-containing medium-entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5The Al layer is effectively etched and removed under the action of HF etchant, and the corresponding nitrogen-containing mid-entropy two-dimensional material (nitrogen-containing mid-entropy MXene) is obtained after the reaction is finished. For nitrogen-containing medium entropy MAX phase material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5And a nitrogen-containing mid-entropy two-dimensional material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5T_xThe results of X-ray diffraction (XRD) analysis were respectively shown in FIG. 21, in which the starting material (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5The (002) peak appears at the position of 12.8 degrees, while the (002) peak of the nitrogen-containing mid-entropy two-dimensional material product after reaction with the etching agent shifts to 6.8 degrees towards a low angle, and other diffraction peaks corresponding to the nitrogen-containing mid-entropy MAX phase disappear, which indicates that the etching agent is completely used for etching (Ti and Ti are fully used for etching)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5Al element in the alloy generates ultrathin two-dimensional nitrogen-containing mid-entropy MXene (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5T_xThe interlayer spacing is significantly increased, which is in accordance with (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂C_0.5N_0.5T_xThe ultra-thin two-dimensional shapes are consistent, and the synthesized nitrogen-containing medium entropy MAX phase (Ti) can be seen by comparing XRD spectrograms_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5Diffraction pattern of (A) and reported quaternary MAX phase Ti₂AlC_0.5N_0.5Consistent with no other impurity peaks of carbides and nitrides, indicating the resulting nitrogen-containing mid-entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5Is a single phase.

Example 9

The invention provides another method for preparing nitrogen-containing medium entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.5N_0.5The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.5N_0.5Medium stoichiometry ofThe ratio (molar ratio) is Ti₂AlN and (Nb)_1/3Ta_1/3Zr_1/3)₂AlC is used as a raw material precursor, and the molar ratio of the AlC to the raw material precursor is Ti₂AlN:(Nb_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio, wherein AlC is 1: 3;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.5N_0.5And (3) powder.

Nitrogen-containing medium entropy two-dimensional material (Ti)_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.5N_0.5The preparation of (1) comprises:

etching: 40ml of concentrated hydrochloric acid and 2g of LiF were mixed uniformly to obtain an etchant, and 1g of the nitrogen-containing medium entropy MAX phase (Ti) obtained in this example was used_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.5N_0.5Placing the mixture into an etching agent, reacting for 24 hours at 50 ℃, and after the reaction is finished, performing centrifugal separation, water washing and drying treatment to obtain the nitrogen-containing intermediate-entropy two-dimensional material (Ti)_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.5N_0.5T_x(wherein T is_xRepresents a functional group contained).

Example 10

The invention provides another method for preparing nitrogen-containing medium entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25V_0.25)₂AlC_0.5N_0.5The preparation method comprises the following steps:

the material preparation step: according to the formula of the medium entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25V_0.25)₂AlC_0.5N_0.5In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₂AlN and (V)_1/3Ta_1/3Zr_1/3)₂AlC is used as a raw material precursor, and the molar ratio of the AlC to the raw material precursor is Ti₂AlN:(V_1/ ₃Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio, wherein AlC is 1: 3;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25V_0.25)₂AlC_0.5N_0.5And (3) powder.

Nitrogen-containing medium entropy two-dimensional material (Ti)_0.25Ta_0.25Zr_0.25V_0.25)₂AlC_0.5N_0.5The preparation of (1) comprises:

etching: 40ml of 48% HF was used as an etchant, and 1g of the nitrogen-containing medium entropy MAX phase (Ti) obtained in the step (1) of this example was used_0.25Ta_0.25Zr_0.25V_0.25)₂AlC_0.5N_0.5Placing in an etching agent, reacting for 24h at 50 ℃, and after the reaction is finished, performing centrifugal separation, water washing and drying treatment to obtain the nitrogen-containing mesoentropy two-dimensional material (Ti) of the accordion_0.25Ta_0.25Zr_0.25V_0.25)₂AlC_0.5N_0.5T_x(wherein T is_xRepresents a functional group contained).

Example 11

The invention provides another method for preparing nitrogen-containing medium entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5Preparation method of (1)The method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2Nb_0.2)₂AlC_0.5N_0.5In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₄AlN₃、Nb₂AlC、Ta₂AlC、Zr₂AlC and Al are used as raw material precursors, and the molar ratio of the AlC to the Al is Ti₄AlN₃:Nb₂AlC:Ta₂AlC:Zr₂Accurately weighing each raw material precursor according to the corresponding molar ratio, wherein AlC is 1:1:1:1: 2;

Example 12

the material preparation step: according to the formula of the medium entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₄AlN₃、Nb₂AlC、Ta₂AlC、V₂AlC and Al are used as raw material precursors, and the molar ratio of the AlC to the Al is Ti₄AlN₃:Zr₂AlC:Ta₂AlC:V₂Accurately weighing each raw material precursor according to the corresponding molar ratio, wherein AlC is 1:1:1:1: 2;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the cooled block, and grinding to obtain the nitrogen-containing intermediate entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5And (3) powder.

Example 13

The invention provides another method for preparing nitrogen-containing medium entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25V_0.25)₂AlC_0.75N_0.25The preparation method comprises the following steps:

the material preparation step: according to the formula of the medium entropy MAX phase (Ti)_0.4Ta_0.2Zr_0.2V_0.2)₂AlC_0.5N_0.5In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₂AlN、Nb₂AlC、Ta₂AlC、V₂AlC and Al are used as raw material precursors, and the molar ratio of the AlC to the Al is Ti₂AlN:Nb₂AlC:Ta₂AlC:V₂Accurately weighing each raw material precursor according to the corresponding molar ratio, wherein AlC is 1:1:1:1: 2;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the cooled block, and grinding to obtain the nitrogen-containing intermediate entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25V_0.25)₂AlC_0.75N_0.25And (3) powder.

Example 14

The invention provides another method for preparing nitrogen-containing medium entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.75N_0.25The preparation method comprises the following steps:

the material preparation step: according to the formula of the medium entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.75N_0.25In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₂AlN、Nb₂AlC、Ta₂AlC、Zr₂AlC and Al are used as raw material precursors, and the molar ratio of the AlC to the Al is Ti₂AlN:Nb₂AlC:Ta₂AlC:Zr₂Accurately weighing each raw material precursor according to the corresponding molar ratio, wherein AlC is 1:1:1:1: 2;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the cooled block, and grinding to obtain the nitrogen-containing intermediate entropy MAX phase (Ti)_0.25Ta_0.25Zr_0.25Nb_0.25)₂AlC_0.75N_0.25And (3) powder.

Example 15

The invention provides another method for preparing nitrogen-containing high-entropy MAX phase (Ti)_2/7Ta_1/7Zr_1/7Nb_1/7V_1/7Hf_1/7)₂AlC_0.7N_0.3The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_2/7Ta_1/7Zr_1/7Nb_1/7V_1/7Hf_1/7)₂AlC_0.7N_0.3In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₄AlN₃、Nb₂AlC、Ta₂AlC、Zr₂AlC、V₂AlC, HfC and Al are used as raw material precursors, and the molar ratio of the AlC, the HfC and the Al is Ti₄AlN₃:Nb₂AlC:Ta₂AlC:Zr₂AlC:V₂AlC:HfC:Al＝1:1:1:1:1:24, accurately weighing each raw material precursor according to the corresponding molar ratio;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_2/7Ta_1/7Zr_1/ ₇Nb_1/7V_1/7Hf_1/7)₂AlC_0.7N_0.3And (3) powder.

Example 16

The invention provides another method for preparing nitrogen-containing high-entropy MAX phase (Ti)_1/6Ta_1/6Zr_1/6Nb_1/6V_1/6Hf_1/6)₂AlC_0.85N_0.15The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_1/6Ta_1/6Zr_1/6Nb_1/6V_1/6Hf_1/6)₂AlC_0.85N_0.15In a medium stoichiometric ratio (molar ratio) of (A) to (B) using Ti₂AlN、Nb₂AlC、Ta₂AlC、Zr₂AlC、V₂AlC, HfC and Al are used as raw material precursors, and the molar ratio of the AlC, the HfC and the Al is Ti₂AlN:Nb₂AlC:Ta₂AlC:Zr₂V2AlC, HfC and Al are 1:1:1:1:1:2:4, and each raw material precursor is accurately weighed according to the corresponding molar ratio;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the productNitrogen high entropy MAX phase (Ti)_1/6Ta_1/6Zr_1/ ₆Nb_1/6V_1/6Hf_1/6)₂AlC_0.85N_0.15And (3) powder.

Example 17

This example provides a nitrogen-containing high-entropy MAX phase material (Ti)_2/7Nb_1/7Ta_1/7Zr_1/7V_1/7Hf_1/7)₂AlC_0.7N_0.3The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_2/7Nb_1/7Ta_1/7Zr_1/7V_1/7Hf_1/7)₂AlC_0.7N_0.3In the (molar ratio) of Ti₄AlN₃，V₂AlC，(Nb_1/3Ta_1/3Zr_1/3)₂AlC, HfC and Al are used as raw material precursors, and the molar ratio of AlC, HfC and Al is Ti₄AlN₃:V₂AlC:(Nb_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio when AlC is 1:1:3:2: 6;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_2/7Nb_1/7Ta_1/ ₇Zr_1/7V_1/7Hf_1/7)₂AlC_0.7N_0.3And (3) powder.

Example 18

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_2/7Nb_1/7Ta_1/7Zr_1/7V_1/7Hf_1/7)₂AlC_0.7N_0.3In the (molar ratio) of Ti₄AlN₃，Nb₂AlC，(V_1/3Ta_1/3Zr_1/3)₂AlC, HfC and Al are used as raw material precursors, and the molar ratio of AlC, HfC and Al is Ti₄AlN₃:Nb₂AlC:(V_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio when AlC is 1:1:3:2: 6;

Example 19

This example provides a nitrogen-containing high-entropy MAX phase material (Ti)_1/6Ta_1/6Zr_1/6Nb_1/6V_1/6Hf_1/6)₂AlC_0.85N_0.15The preparation method comprises the following steps:

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_1/6Ta_1/6Zr_1/6Nb_1/6V_1/6Hf_1/6)₂AlC_0.85N_0.15In the (molar ratio) of Ti₂AlN，Nb₂AlC，(V_1/3Ta_1/3Zr_1/3)₂AlC, HfC and Al are used as raw material precursors, and the molar ratio of AlC, HfC and Al is Ti₂AlN:Nb₂AlC:(V_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio when AlC is 1:1:3:2: 6;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, cooling along with the furnace, taking out the block obtained after cooling, and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_1/6Ta_1/6Zr_1/ ₆Nb_1/6V_1/6Hf_1/6)₂AlC_0.85N_0.15And (3) powder.

Example 20

the material preparation step: according to the formula of the high-entropy MAX phase (Ti)_1/6Ta_1/6Zr_1/6Nb_1/6V_1/6Hf_1/6)₂AlC_0.85N_0.15In the (molar ratio) of Ti₂AlN，V₂AlC，(Nb_1/3Ta_1/3Zr_1/3)₂AlC, HfC and Al are used as raw material precursors, and the molar ratio of AlC, HfC and Al is Ti₂AlN:V₂AlC:(Nb_1/3Ta_1/3Zr_1/3)₂Accurately weighing each raw material precursor according to the corresponding molar ratio when AlC is 1:1:3:2: 6;

sintering: transferring the ball-milled block into a corundum crucible, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, and cooling along with the furnaceTaking out the block obtained after cooling and grinding to obtain the nitrogen-containing high-entropy MAX phase (Ti)_1/6Ta_1/6Zr_1/ ₆Nb_1/6V_1/6Hf_1/6)₂AlC_0.85N_0.15And (3) powder.

The following is a supplement to the applicant's prior application file during the priority period:

the nitrogen-containing medium-entropy or high-entropy MAX phase material prepared by the method belongs to one type of MAX phase material large family, and the preparation method can also obtain a series of novel medium-entropy or high-entropy MAX phase materials.

The invention also provides a nitrogen-containing medium-entropy or high-entropy MAX phase material which consists of M elements, A elements and X elements and has a chemical general formula of M_n+1AX_nWherein, the M element is at least four metal elements in IIIB, IVB, VB, VIB, VIIB, VIII, IB and IIB groups, the A element is at least one element in VIIB, VIII, IB, IIB, IIIA, IVA, VA and VIA groups, and the X element is nitrogen element and at least one non-metal element in IIIA, IVA, VA and VIA groups; n is 1, 2, 3, 4, 5 or 6.

In some embodiments, the X element is carbon and nitrogen;

in some embodiments, the M element is selected from four or more of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Pt, Au, Ag, Pd, Cu or Bi elements;

in some embodiments, the element A is at least one element selected from the group consisting of Al, Si, P, S, Fe, Cu, Zn, Ga, Ge, As, Cd, In, Sn, Tl, Pb, and Bi.

The invention also provides a nitrogen-containing medium-entropy or high-entropy two-dimensional material, which is obtained by etching the element A in the nitrogen-containing medium-entropy or high-entropy MAX phase material.

The invention also provides a preparation method of the high-entropy MAX phase material, which is characterized by comprising the following steps:

the material preparation step: determining the required amount of raw materials containing each element according to the stoichiometric ratio of each element in the chemical general formula of the high-entropy MAX phase material;

sintering: sintering the raw materials at a preset temperature under the condition of protective atmosphere or vacuum to obtain a high-entropy MAX phase material;

wherein the high-entropy MAX phase material consists of M element, A element and X element, and the chemical general formula of the high-entropy MAX phase material is M_n+1AX_nWherein the M element is at least five metal elements selected from IIIB, IVB, VB, VIB, VIIB, VIII, IB and IIB groups; a is selected from at least one of VIIB, VIII, IB, IIB, IIIA, IVA, VA and VIA group elements; the X element is at least one nonmetal element selected from IIIA, IVA, VA and VIA; the raw materials comprise: at least one raw MAX phase, wherein the element species number of M element in the raw MAX phase is between 1 and 4.

In a preferred embodiment, the raw MAX phase comprises: a medium entropy MAX phase, wherein the element number of M elements in the medium entropy MAX phase is 3 or 4; namely, the invention provides a preparation method for preparing a high-entropy MAX phase from a medium-entropy MAX phase, wherein the high-entropy MAX phase is prepared from the medium-entropy MAX phase through thermodynamic analysis, and compared with a method for sintering simple-substance elements at high temperature, the preparation method has the lowest formation energy, and can synthesize various high-entropy MAX phase materials, namely, a series of novel high-entropy MAX phase materials which are difficult to synthesize by conventional methods, such as high-entropy MAX phase materials with more than 6 elements in M position, and the like.

In a preferred embodiment, all of the above starting materials are MAX phase materials.

In some embodiments, the raw material further comprises a compound of an element a and the element X; and/or, a compound of an element M with an element X; and/or one or more of simple substance of M element, simple substance of A element or simple substance of X element.

The invention also provides a preparation method of the high-entropy two-dimensional material, wherein the element A in the high-entropy MAX phase material obtained by the preparation method is obtained by etching; preferably, the etching agent is one or more of halogen simple substance, halogen hydride or nitrogen hydride; or the etchant is a hydrogen halide solution, an acid solution + halide salt system, or a halogen metal salt.

The technical features of the present invention are described below by specific embodiments:

example 21

This example provides a novel high entropy MAX material (Ti)_1/6Zr_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6)₂The AlC is prepared by mixing an entropy MAX phase in the raw material with other MAX phases and sintering at high temperature, wherein the entropy MAX phase in the raw material is (Ti)_1/ ₄Zr_1/4Nb_1/4Ta_1/4)₂AlC, the other MAX phases are VCrAlC, comprising the steps of:

1) weighing the medium entropy MAX phase (Ti) with the corresponding mass according to the stoichiometric ratio (molar ratio) of 2:1_1/4Zr_1/4Nb_1/ ₄Ta_1/4)₂Grinding and uniformly mixing AlC and VCrAlC powder, and cold pressing for 5min at 10 MPa;

2) transferring the cold-pressed block into a high-temperature sintering furnace, heating to 1500 ℃ at a speed of 5 ℃/min under Ar atmosphere, preserving heat for 1h, and cooling along with the furnace;

3) and taking out the block obtained after cooling and grinding to obtain the target high-entropy MAX-phase powder.

The target product was subjected to X-ray diffraction (XRD) measurement, and as a result, as shown in fig. 22a, a MAX-phase characteristic (002) diffraction peak appeared around 13 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 22b, can show that the target product has an obvious MAX phase characteristic layered structure, which is consistent with the XRD result, demonstrating successful synthesis of the MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Ti)_1/6Zr_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6)₂C。

Example 22

This example provides a novel high entropy MAX phase material (Ti)_1/8Zr_1/8Nb_1/8Ta_1/8V_1/4Cr_1/4)₂The AlC is prepared by mixing a medium-entropy MAX phase and a binary MAX phase and sintering at high temperature, wherein the medium-entropy MAX phase in the raw material is (Ti)_1/ ₄Zr_1/4Nb_1/4Ta_1/4)₂AlC, other MAX phases are VCrAlC, comprising the steps of：

1) Weighing medium entropy MAX phase (Ti) with corresponding mass according to the stoichiometric ratio of 1:1_1/4Zr_1/4Nb_1/4Ta_1/4)₂Grinding and uniformly mixing AlC and VCrAlC powder, and cold pressing for 5min at 10 MPa;

The target product was subjected to an X-ray diffraction (XRD) test, and as a result, as shown in fig. 23a, a MAX-phase characteristic (002) diffraction peak appeared around 13 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 23b, can show that the target product has an obvious MAX phase characteristic layered structure, which is consistent with the XRD result, demonstrating successful synthesis of the MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Ti)_1/6Zr_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6)₂C。

Example 23

This example provides a novel high entropy MAX material (Ti)_1/5Nb_1/5Ta_1/5Zr_1/5Cr_1/5)₄AlC₃The preparation method is prepared by mixing the medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Ti)_1/4Zr_1/ ₄Nb_1/4Ta_1/4)₂AlC, other MAX phases being Cr₂AlC, comprising the steps of:

1) weighing the medium entropy MAX phase (Ti) with the corresponding mass according to the stoichiometric ratio of 4:1_1/4Zr_1/4Nb_1/4Ta_1/4)₂AlC and Cr₂And grinding and uniformly mixing AlC powder and cold pressing for 5min at 10 MPa.

2) And transferring the cold-pressed block into a high-temperature sintering furnace, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, and cooling along with the furnace.

The target product was subjected to X-ray diffraction (XRD) measurement, and as a result, as shown in fig. 24a, a MAX-phase characteristic (002) diffraction peak appeared around 7.5 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 24b, can show that the target product has an obvious MAX phase characteristic layered structure, which is consistent with the XRD result, demonstrating successful synthesis of the MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Ti)_1/5Nb_1/5Ta_1/5Zr_1/5Cr_1/5)₄AlC₃。

Example 24

This example provides a novel high entropy MAX material (Ti) of the present invention_1/6Zr_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6)₂The preparation method of AlC is prepared by mixing a medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Ti)_1/4Zr_1/4Nb_1/4Ta_1/4)₂AlC, other MAX phases being V₂AlC and Cr₂AlC, comprising the steps of:

1) weighing medium entropy MAX phase (Ti) with corresponding mass according to the stoichiometric ratio of 4:1:1_1/4Zr_1/4Nb_1/4Ta_1/4)₂AlC and V₂AlC and Cr₂Grinding and uniformly mixing AlC powder, and cold pressing for 5min at 10 MPa;

The target product was subjected to X-ray diffraction (XRD) measurement, and as a result, as shown in fig. 25a, a MAX-phase characteristic (002) diffraction peak appeared around 13 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 25b, can show that the target product has an obvious MAX phase characteristic layered structure, which is consistent with the XRD result, demonstrating successful synthesis of the MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Ti)_1/6Zr_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6)₂C。

Example 25

This example provides a novel high entropy MAX material (Ti) of the present invention_1/5Zr_1/5Nb_1/5Ta_1/5V_1/10Cr_1/10)₄AlC₃The preparation method is prepared by mixing the medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Ti)_1/4Zr_1/4Nb_1/4Ta_1/4)₂AlC, the other MAX phases are VCrAlC, comprising the steps of:

1) weighing the medium entropy MAX phase (Ti) with the corresponding mass according to the stoichiometric ratio of 4:1_1/4Zr_1/4Nb_1/4Ta_1/4)₂Grinding and uniformly mixing AlC and VCrAlC powder, and cold pressing for 5min at 10 MPa;

The target product was subjected to X-ray diffraction (XRD) measurement, and as a result, as shown in fig. 26a, a MAX-phase characteristic (002) diffraction peak appeared around 7.4 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 26b, can show that the target product has an obvious MAX phase characteristic layered structure, which is consistent with the XRD result, demonstrating successful synthesis of the MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Ti)_1/5Zr_1/5Nb_1/5Ta_1/5V_1/10Cr_1/10)₄C₃。

Example 26

This example provides a novel high entropy MAX material (Ti) of the present invention_5/26Zr_5/26Nb_5/26Ta_5/26V_5/26Cr_1/26)₂The preparation method of AlC is prepared by mixing a medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Ti)_1/4Zr_1/4Nb_1/4Ta_1/4)₂AlC, other MAX phases being V₂AlC、Cr₂AlC, comprising the steps of:

1) weighing the medium entropy MAX phase (Ti) with the corresponding mass according to the stoichiometric ratio of 4:1:0.2_1/4Zr_1/4Nb_1/4Ta_1/4)₂AlC and V₂AlC、Cr₂And grinding and uniformly mixing AlC powder and cold pressing for 5min at 10 MPa.

2) And transferring the cold-pressed block into a high-temperature sintering furnace, heating to 1400 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 2h, and cooling along with the furnace.

The target product was subjected to an X-ray diffraction (XRD) test, and as a result, as shown in fig. 27a, a MAX-phase characteristic (002) diffraction peak appeared around 13 degrees. Scanning Electron Microscope (SEM) analysis of the target product showed that the target product had an obvious MAX phase characteristic layered structure, consistent with the XRD result, as shown in fig. 27 b. The successful synthesis of the MAX phase was demonstrated, belonging to 211 pure MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Ti)_5/26Zr_5/26Nb_5/26Ta_5/26V_5/26Cr_1/26)₂C。

Example 27

This example provides a novel high-entropy MAX material (Zr) of the present invention_1/4Nb_1/4Ta_1/4V_1/8Cr_1/8)₄AlC₃The preparation method is prepared by mixing the medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Nb)_1/ ₃Ta_1/3Zr_1/3)₂AlC, the other MAX phases are VCrAlC, comprising the steps of:

1) weighing medium entropy MAX phase (Zr) with corresponding mass according to the stoichiometric ratio of 3:1_1/3Nb_1/3Ta_1/3)₂And grinding and uniformly mixing AlC and VCrAlC powder, and cold pressing for 5min at 10 MPa.

The target product was subjected to X-ray diffraction (XRD) measurement, and as a result, as shown in fig. 28a, a MAX-phase characteristic (002) diffraction peak appeared around 7.4 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 28b, can show that the target product has an obvious MAX phase characteristic layered structure, which is consistent with the XRD result, demonstrating successful synthesis of the MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Zr)_1/4Nb_1/4Ta_1/4V_1/8Cr_1/8)₄C₃。

Example 28

This example provides a novel high-entropy MAX material (Zr) of the present invention_1/5Nb_1/5Ta_1/5V_1/5Cr_1/5)₂The AlC is prepared by mixing a medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Zr)_1/ ₃Nb_1/3Ta_1/3)₂AlC, the other MAX phases are VCrAlC, comprising the steps of:

1) weighing medium entropy MAX phase (Zr) with corresponding mass according to the stoichiometric ratio of 3:2_1/3Nb_1/3Ta_1/3)₂And grinding and uniformly mixing AlC and VCrAlC powder, and cold pressing for 5min at 10 MPa.

2) And transferring the cold-pressed block to a high-temperature sintering furnace, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, and cooling along with the furnace.

The target product was subjected to an X-ray diffraction (XRD) test, and as a result, as shown in fig. 29a, a MAX-phase characteristic (002) diffraction peak appeared around 13 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 29b, can show that the target product has an obvious MAX phase characteristic layered structure, which is consistent with the XRD result, demonstrating successful synthesis of the MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Zr)_1/5Nb_1/5Ta_1/5V_1/5Cr_1/5)₂C。

Example 29

This example provides a novel high entropy M of the present inventionAX Material (Zr)_1/5Nb_1/5Ta_1/5V_1/5Cr_1/5)₂The AlC is prepared by mixing a medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Zr)_1/ ₃Nb_1/3Ta_1/3)₂AlC, other MAX phases being V₂AlC and Cr₂AlC, comprising the steps of:

1) weighing medium entropy MAX phase (Zr) with corresponding mass according to the stoichiometric ratio of 3:1:1 of chemical molar_1/3Nb_1/3Ta_1/3)₂AlC and V₂AlC and Cr₂And grinding and uniformly mixing AlC powder and cold pressing for 5min at 10 MPa.

The target product was subjected to X-ray diffraction (XRD) measurement, and as a result, as shown in fig. 30a, a MAX-phase characteristic (002) diffraction peak appeared at around 12 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 30b, can show that the target product has an obvious MAX phase characteristic layered structure, consistent with the XRD result. The successful synthesis of the MAX phase was demonstrated. Etching Al to obtain a high-entropy two-dimensional material (Zr)_1/5Nb_1/5Ta_1/5V_1/5Cr_1/5)₂C。

Example 30

This example provides a novel high-entropy MAX material (Zr) of the present invention_1/7Nb_1/7Ta_1/7V_2/7Cr_2/7)₂The AlC is prepared by mixing a medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Nb)_1/ ₃Ta_1/3Zr_1/3)₂AlC, other MAX phases being V₂AlC and Cr₂AlC, comprising the steps of:

1) weighing medium entropy MAX phase (Zr) with corresponding mass according to the stoichiometric ratio of 3:2:2_1/3Nb_1/3Ta_1/3)₂AlC and V₂AlC and Cr₂Grinding and uniformly mixing AlC powder, and cold pressing for 5min at 10 MPa;

The target product was subjected to an X-ray diffraction (XRD) test, and as a result, as shown in fig. 31a, a MAX-phase characteristic (002) diffraction peak appeared around 13 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 31b, can show that the target product has an obvious MAX phase characteristic layered structure, consistent with the XRD result. The successful synthesis of the MAX phase was demonstrated. Etching Al to obtain a high-entropy two-dimensional material (Zr)_1/7Nb_1/7Ta_1/7V_2/7Cr_2/7)₂C。

Example 31

This example provides a novel high-entropy MAX material (Zr) of the present invention_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6Ti_1/6)₂The AlC is prepared by mixing a medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (Nb)_1/3Ta_1/3Zr_1/3)₂AlC, other MAX phases being VCrAlC and Ti₂AlC, comprising the steps of:

1) weighing medium entropy MAX phase (Zr) with corresponding mass according to the stoichiometric ratio of 3:2:1_1/3Nb_1/3Ta_1/3)₂AlC with VCrAlC and Ti₂Grinding and uniformly mixing AlC powder, and cold pressing for 5min at 10 MPa;

2) transferring the cold-pressed block to a high-temperature sintering furnace, heating to 1500 ℃ at the speed of 5 ℃/min under the Ar atmosphere, preserving heat for 1h, and cooling along with the furnace;

The target product was subjected to an X-ray diffraction (XRD) test, and as a result, as shown in fig. 32a, a MAX-phase characteristic (002) diffraction peak appeared around 13 degrees. The target product is analyzed by a Scanning Electron Microscope (SEM), and the result is shown in the figure32b, it can be seen that the target product has a distinct MAX phase characteristic layered structure, consistent with XRD results. The successful synthesis of the MAX phase was demonstrated. Etching Al to obtain a high-entropy two-dimensional material (Zr)_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6Ti_1/6)₂C。

Example 32

This example provides a novel high-entropy MAX material (Zr) of the present invention_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6Ti_1/6)₂The preparation method of AlC is prepared by mixing a medium entropy MAX phase and other MAX phases and sintering at high temperature, wherein the medium entropy MAX phase in the raw material is (V)_1/3Ta_1/3Zr_1/3)₂AlC, other MAX phases being Cr₂AlC、Ti₂AlC and Nb₂AlC, comprising the steps of:

1) weighing the medium entropy MAX phase (Zr) with the corresponding mass according to the stoichiometric ratio of 3:1:1:1_1/4Nb_1/4Ta_1/4)₂AlC and Cr₂AlC、Ti₂AlC and Nb₂Grinding and uniformly mixing AlC powder, and cold pressing for 5min at 10 MPa;

The target product was subjected to an X-ray diffraction (XRD) test, and as a result, as shown in fig. 33a, a MAX-phase characteristic (002) diffraction peak appeared around 13 degrees. Scanning Electron Microscope (SEM) analysis of the target product, the result of which is shown in fig. 33b, can show that the target product has an obvious MAX phase characteristic layered structure, which is consistent with the XRD result, demonstrating successful synthesis of the MAX phase. Etching Al to obtain a high-entropy two-dimensional material (Zr)_1/6Nb_1/6Ta_1/6V_1/6Cr_1/6Ti_1/6)₂C。

The MAX phase material is used as the raw material, and the formation energy of the MAX phase with high entropy can be reduced thermodynamically, so that the MAX phase material with high entropy and abundant varieties is prepared; meanwhile, in the high-temperature sintering process of the preparation method, phase separation is not easy to generate, and the purity of the product is high. In the technical scheme that the raw material contains at least one medium-entropy MAX phase (the medium-entropy MAX phase means that three or four metal elements exist on the M position in the MAX phase material), because a multi-element MAX phase structure skeleton exists in the raw material, in the high-temperature sintering process, the metal elements in other raw materials are diffused into the M position in the structure of the entropy MAX phase in the raw material, and the obtained high-entropy MAX phase material does not generate phase separation and has the characteristic of high purity (can be seen through XRD test); from thermodynamic analysis, the high-entropy MAX phase is prepared from the medium-entropy MAX phase, and compared with the high-temperature sintering of simple substance elements, the high-entropy MAX phase has the lowest formation energy, and can be synthesized to obtain high-entropy MAX phase materials with abundant types, namely, a series of novel high-entropy MAX phase materials which are difficult to synthesize by a conventional method, such as high-entropy MAX phase materials with more than 6 elements in M position. The high-entropy MAX phase material is used as a precursor, the component A is etched away, and the high-entropy MAX phase material with rich varieties can be further synthesized.

The applicant also obtained other types of high-entropy MAX phase materials and high-entropy two-dimensional materials by the above-mentioned preparation method, summarized in the following table:

the high-entropy MAX phase material can be prepared by using M, A and X elements as raw materials, but in the high-temperature sintering process, M and X are easy to react to generate MX compounds to generate phase separation, so that a high-purity high-entropy ceramic material is difficult to obtain. Therefore, the preparation method of the high-entropy MAX phase material provided by the invention provides a new preparation path for the high-entropy ceramic material, can greatly enrich the variety of the high-entropy ceramic material, and has wide application prospect in the fields of catalysis, sensors, electronic devices, supercapacitors, batteries, electromagnetic shielding, wave-absorbing materials, corrosion-resistant materials, superconducting materials and the like by utilizing the special physical and chemical properties of the high-entropy ceramic material

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and its practical application. It is intended that the scope of the invention be defined by the claims and their equivalents.

Claims

1. A method for preparing a nitrogen-containing medium-entropy or high-entropy MAX phase material is characterized by comprising the following steps:

at least one nitrogen-containing MAX phase and a plurality of nitrogen-free MAX phases are used as raw materials for reaction; the sum of the element types of M in the MAX phase is more than four, and the nitrogen-containing MAX phase material with medium entropy or high entropy is prepared;

or at least one nitrogen-containing MAX phase, a plurality of transition metal simple substances or compounds and A simple substances or compounds are used as raw materials to react, the sum of the element types of M in the MAX phase and the element types of the plurality of transition metals is more than four, and the nitrogen-containing MAX phase material with medium entropy or high entropy is prepared.

2. The preparation method according to claim 1, wherein in the obtained nitrogen-containing medium-entropy or high-entropy MAX phase material, M is at least four metal elements selected from groups IIIB, IVB, VB, VIB, VIIB, VIII, IB and IIB; a is selected from at least one of VIIB, VIII, IB, IIB, IIIA, IVA, VA and VIA group elements; the X element is nitrogen element and at least one nonmetal element in IIIA, IVA, VA and VIA.

3. The method of claim 1, wherein in the nitrogen-containing MAX phase, X is carbon and nitrogen;

and/or, said M or said transition metal is selected from elements of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Pt, Au, Ag, Pd, Cu or Bi;

and/or the compound of the transition metal is a carbide of the transition metal;

and/or A is selected from Al, Si, P, S, Fe, Cu, Zn, Ga, Ge, As, Cd, In, Sn, Tl, Pb or Bi elements.

4. The method of claim 1, further comprising, prior to performing the reaction:

grinding: grinding the raw materials;

and/or, a pressing step: pressing the raw materials to form the composite material; preferably, the pressurization pressure is between 10MPa and 50 MPa.

5. The method of claim 1, wherein the reaction temperature is between 600 ℃ and 3000 ℃; preferably, between 1000 ℃ and 1700 ℃;

and/or the reaction time is between 1h and 20 h.

6. The method of claim 3, wherein the nitrogen-containing medium-or high-entropy MAX phase material is produced with an atomic ratio C: N of (1-x): x, wherein (0< x < 1);

and/or the element types of M in the prepared nitrogen-containing medium-entropy or high-entropy MAX phase material are four, five or six.

7. A preparation method of a nitrogen-containing medium-entropy or high-entropy two-dimensional material is characterized by comprising the following steps:

reacting the nitrogen-containing medium-entropy or high-entropy MAX phase material obtained by the preparation method according to any one of claims 1 to 6 with an etching agent to etch the component A therein to obtain the nitrogen-containing medium-entropy or high-entropy two-dimensional material.

8. The method of claim 7, wherein the etchant is one or more of a halogen element, a halogen hydride, or a nitrogen hydride;

or the etchant is a hydrogen halide solution, an acid solution + halide salt system, or a halogen metal salt.

9. The production method according to claim 7 or 8, wherein the reaction is vapor etching, and the etchant is in a vapor phase or can be converted into a vapor phase for etching;

and/or the thickness of the obtained nitrogen-containing medium-entropy or high-entropy two-dimensional material is between 2nm and 10 nm.

10. A nitrogen-containing medium-entropy or high-entropy MAX-phase material obtained by the production method according to any one of claims 1 to 6; or, the nitrogen-containing medium-entropy or high-entropy two-dimensional material obtained by the preparation method according to any one of claims 7 to 9 is applied to catalysis, sensors, electronic devices, supercapacitors, batteries, electromagnetic shielding, wave-absorbing materials, corrosion-resistant materials, or superconducting materials.

11. A nitrogen-containing medium-entropy or high-entropy MAX phase material is characterized by consisting of M elements, A elements and X elements, and the chemical general formula of the nitrogen-containing medium-entropy or high-entropy MAX phase material is M_n+1AX_nWherein the M element is at least four metal elements selected from IIIB, IVB, VB, VIB, VIIB, VIII, IB and IIB, the A element is at least one element selected from VIIB, VIII, IB, IIB, IIIA, IVA, VA and VIA, and the X element is nitrogen element and at least one non-metal element selected from IIIA, IVA, VA and VIA; n is 1, 2, 3, 4, 5 or 6.

12. A nitrogen-containing medium-or high-entropy MAX-phase material according to claim 11, wherein the X element is a carbon and nitrogen element;

and/or the M element is more than four elements selected from Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Fe, Co, Ni, Pt, Au, Ag, Pd, Cu or Bi;

and/or the A element is at least one element selected from Al, Si, P, S, Fe, Cu, Zn, Ga, Ge, As, Cd, In, Sn, Tl, Pb or Bi.

13. A nitrogen-containing medium-entropy or high-entropy two-dimensional material, characterized in that it is obtained by etching the a element of the nitrogen-containing medium-entropy or high-entropy MAX-phase material as claimed in claim 11 or 12.

14. A method for preparing a high-entropy MAX phase material is characterized by comprising the following steps:

wherein the high-entropy MAX phase material consists of M element, A element and X element, and the chemical general formula of the high-entropy MAX phase material is M_n+1AX_nWherein the M element is at least five metal elements selected from IIIB, IVB, VB, VIB, VIIB, VIII, IB and IIB groups; a is selected from at least one of VIIB, VIII, IB, IIB, IIIA, IVA, VA and VIA group elements; the X element is at least one nonmetal element selected from IIIA, IVA, VA and VIA;

the raw materials comprise: at least one raw MAX phase, wherein the element species number of M element in the raw MAX phase is between 1 and 4.

15. The method of claim 14, wherein the starting MAX phase comprises: a medium entropy MAX phase, wherein the element number of M elements in the medium entropy MAX phase is 3 or 4;

and/or the raw materials are all MAX phase materials.

16. The method of claim 14 or 15, wherein the feedstock further comprises: a compound of said element A and said element X;

and/or, a compound of said M element with said X element;

and/or one or more of the simple substance of the M element, the simple substance of the A element or the simple substance of the X element.

17. A method for preparing a high-entropy two-dimensional material, which is characterized in that the element a in the high-entropy MAX-phase material obtained by the preparation method according to any one of claims 14 to 16 is etched; preferably, the etching agent is one or more of halogen simple substance, halogen hydride or nitrogen hydride; or the etchant is a hydrogen halide solution, an acid solution + halide salt system, or a halogen metal salt.

18. A nitrogen-containing medium-or high-entropy MAX phase material of claim 11 or 12; or, the use of the nitrogen-containing medium-entropy or high-entropy two-dimensional material of claim 13 in catalysis, sensors, electronic devices, supercapacitors, batteries, electromagnetic shielding, wave-absorbing materials, corrosion-resistant materials, or superconducting materials.

19. A high entropy MAX phase material obtained by the production method according to any one of claims 14 to 16; or, the use of the high-entropy two-dimensional material of claim 17 in catalysis, sensors, electronics, supercapacitors, batteries, electromagnetic shielding, wave-absorbing materials, corrosion-resistant materials, or superconducting materials.