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CN-121974346-A - High-entropy halogen end group MXene material and preparation method thereof

CN121974346ACN 121974346 ACN121974346 ACN 121974346ACN-121974346-A

Abstract

The invention belongs to the technical field of new material preparation, and particularly discloses a high-entropy halogen end group MXene material and a preparation method thereof, comprising the following steps of S1, mixing a high-entropy MAX sample, an etching agent and molten salt raw materials in proportion, and then carrying out high-temperature annealing treatment under the protection of inert gas; S2, heating and washing by adopting a washing solvent to remove impurities, and then performing suction filtration and washing by adopting ultrapure water until the solution is neutral, and S3, performing drying treatment to obtain the accordion-shaped multilayer single-end-group high-entropy MXene. The high-entropy halogen end group MXene material and the preparation method thereof are adopted to realize the precise regulation and control of the high-entropy MXene surface functional groups, and the application performance of the high-entropy halogen end group MXene material in the target fields of energy storage, catalysis and the like is improved by regulating and controlling the reaction temperature, the heat preservation time and the types of the etchant oriented regulating and controlling the product surface functional groups in molten salt.

Inventors

  • YANG JINLIN
  • TIAN XINLONG
  • Ge Yanzeng
  • LIU BAOQUAN

Assignees

  • 海南大学

Dates

Publication Date
20260505
Application Date
20260309

Claims (10)

  1. 1. The preparation method of the high-entropy halogen end group MXene material is characterized by comprising the following steps of: S1, mixing a high-entropy MAX sample, an etchant and molten salt raw materials in proportion, and then carrying out high-temperature annealing treatment under the protection of inert gas to obtain an etching MAX phase for etching out main group elements in the high-entropy MAX phase; s2, heating and washing the etching MAX phase obtained in the step S1 by adopting a washing solvent until impurities are removed, and then performing suction filtration and washing by adopting ultrapure water until the solution is neutral to obtain high-purity high-entropy MXene; And S3, drying the high-entropy MXene obtained in the step S2 to obtain the accordion-shaped multi-layer single-end-group high-entropy MXene.
  2. 2. The method of claim 1, wherein in S1, the high entropy MAX sample is one of TiVNbMoAlC 3 、TiVCrMoAlC 3 , the etchant is one of CuCl 2 、CuBr 2 and CuI, and the molten salt raw material includes NaCl and KCl.
  3. 3. The preparation method of the high-entropy halogen end group MXene material according to claim 2, wherein the molar ratio of the high-entropy MAX sample to the etchant to the NaCl to the KCl is 1:3-6:2-4:2-4.
  4. 4. The method for preparing a high-entropy halogen end group MXene material according to claim 1, wherein in S1, the inert gas is one or two of argon and nitrogen.
  5. 5. The method for preparing the high-entropy halogen end group MXene material according to claim 1, wherein in S1, the annealing temperature of the high-temperature annealing treatment is 600-800 ℃, and the annealing time is 5-8 hours.
  6. 6. The method for preparing the high-entropy halogen end group MXene material according to claim 1, wherein in S2, the washing solvent comprises ammonium chloride and ammonia water, wherein the concentration of the ammonium chloride is 2-4 mol/L, and the concentration of the ammonia water is 1-3 mol/L.
  7. 7. The method for preparing the high-entropy halogen end group MXene material according to claim 1, wherein in S2, the washing solvent adopts ammonium persulfate with the concentration of 3-5 mol/L.
  8. 8. The preparation method of the high-entropy halogen end group MXene material according to any one of claims 6 and 7, which is characterized in that the heating and washing temperature is 40-50 ℃, the washing time is 4-8 hours, and then the solution is subjected to suction filtration and washing by using ultrapure water for 8-15 times until the solution is neutral.
  9. 9. The method for preparing the high-entropy halogen end group MXene material according to claim 1, wherein in S3, the drying treatment is performed in a vacuum oven with the temperature of 40-50 ℃.
  10. 10. A high-entropy halogen end group MXene material prepared by the preparation method of the high-entropy halogen end group MXene material according to any one of claims 1-9, which is characterized by comprising TiVNbMoC 3 Cl x 、TiVNbMoC 3 Br x 、TiVNbMoC 3 I x 、TiVCrMoC 3 Cl x 、TiVCrMoC 3 Br x and TiVCrMoC 3 I x .

Description

High-entropy halogen end group MXene material and preparation method thereof Technical Field The invention relates to the technical field of new material preparation, in particular to a high-entropy halogen end group MXene material and a preparation method thereof. Background MXene is taken as a two-dimensional layered material formed by transition metal carbide, nitride or carbonitride, and has great application potential in the fields of energy storage, catalysis, electromagnetic shielding and the like by virtue of excellent conductivity, tunable surface functional groups and good chemical stability. Such materials are typically prepared by selective etching of three-dimensional MAX phase precursors to remove a-site metallic elements (e.g., al, si, etc.) therefrom, with properties highly dependent on the controllability of the synthesis process and the structural integrity of the product. The traditional MXene synthesis mainly depends on a hydrofluoric acid (HF) solution etching method, and the method can remove A-site metal elements, but has the obvious defects that HF has strong corrosiveness and toxicity, serious corrosion is caused to experimental equipment, serious environmental and safety risks are brought, and large-scale production is greatly limited. Meanwhile, the preparation period of the method is as long as several hours or even tens of hours, the product is easy to damage the crystal structure due to uneven etching, the surface functional group regulation precision is low, and the application requirement of the high-performance material is difficult to meet. To overcome the above problems, a molten salt etching method has been developed which can rapidly achieve etching of the MAX phase by utilizing the high reactivity of molten salt at high temperature. According to different molten salt types, the method can be divided into two types, namely fluorine-containing molten salt etching and Lewis acid molten salt etching, wherein the former etches the metal element A through HF generated by decomposition, and the latter realizes selective stripping by means of redox reaction of ZnCl 2、CuCl2 and other salts, and the method is successfully expanded to the preparation of various MXene such as V 4C3Tx、Nb4C3Tx. In the prior art, along with the upgrading of material performance requirements, the development of high-entropy MXene becomes a new research hot spot. The material realizes the cooperative optimization of the electronic structure and the surface activity by introducing various transition metal elements (such as Ti, V, nb, mo and the like) at the M position and by means of the cocktail effect and the lattice distortion effect. However, the synthesis of the high-entropy MXene faces greater challenges, on one hand, the difficulty of A-site etching is obviously increased due to the existence of various metal elements in the high-entropy MAX phase precursor, element segregation and structural collapse are easily caused by a traditional HF method, and in addition, the performance of the high-entropy MXene is directly influenced by the types and the contents of surface functional groups of the high-entropy MXene, but the regulation and control precision of the functional groups by the traditional method is insufficient, and the directional optimization of active sites and electron transmission characteristics cannot be realized. Therefore, the high-entropy halogen end group MXene material and the preparation method thereof are developed, and the high-efficiency and green synthesis method of a high-entropy system is adapted, so that the problems of low etching efficiency, poor product uniformity and high environmental risk in the traditional process are solved, the structure controllability and the performance improvement of the high-entropy MXene are realized, and the high-entropy halogen end group MXene material becomes a key technical bottleneck for promoting the breakthrough of the MXene material to high-end application. Disclosure of Invention The invention aims to provide a high-entropy halogen end group MXene material and a preparation method thereof, which realize the accurate regulation and control of high-entropy MXene surface functional groups, and the application performance of the high-entropy halogen end group MXene material in the target fields of energy storage, catalysis and the like is improved by regulating and controlling the reaction temperature, the heat preservation time and the types of the etchant oriented regulating and controlling the product surface functional groups in molten salt. In order to achieve the above purpose, the invention provides a preparation method of a high-entropy halogen end group MXene material, which comprises the following steps: S1, mixing a high-entropy MAX sample, an etchant and molten salt raw materials in proportion, and then carrying out high-temperature annealing treatment under the protection of inert gas to obtain an etching MAX phase for etc