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CN-122010116-A - Preparation method and application of crystalline-amorphous heterostructure composite material

CN122010116ACN 122010116 ACN122010116 ACN 122010116ACN-122010116-A

Abstract

The invention provides a preparation method and application of a crystalline/amorphous heterostructure composite material, and relates to the fields of electromagnetic wave absorption, conversion and protection of nanocomposite materials. The method adopts the micro-oxygen amorphization treatment of ammonium persulfate to controllably induce the Ti 3 C 2 T x MXene nano-sheet part with good crystallinity to be converted into the disordered amorphous state in situ, so that the component is irreversibly converted from the ordered crystalline state to the disordered amorphous state, thereby forming a rich and uniform crystalline state/amorphous heterogeneous interface structure in the MXene nano-sheet. An interface electron transfer channel is formed between the constructed crystalline region and the amorphous region through an interface chemical bond, so that strong interface interaction is promoted. The formation of the abundant crystalline/amorphous heterogeneous interface enables the dielectric polarization response of the MXene nano-sheet to be obviously optimized, generates strong interface polarization loss and promotes the effective conversion of electromagnetic wave energy.

Inventors

  • WANG BAOJUN
  • ZHANG HUI
  • WANG HUI
  • ZI ZHENFA
  • MA XIAOHANG
  • WEI YIYONG

Assignees

  • 合肥师范学院

Dates

Publication Date
20260512
Application Date
20251016

Claims (9)

  1. 1. The crystalline/amorphous heterostructure composite material is characterized by being A/C-MXene, and comprises the steps of utilizing the strong oxidizing property of ammonium persulfate to induce a controllable micro-oxygen amorphization conversion process of a highly-crystallized two-dimensional transition metal carbide T 3 C 2 T x MXene nano-sheet to form the nano-composite material with a crystalline/amorphous heterostructure.
  2. 2. A method of preparing a crystalline/amorphous heterostructure composite material according to claim 1, comprising the steps of: S1, adding a two-dimensional lamellar transition metal carbide MAX phase Ti 3 AlC 2 raw material into a hydrofluoric acid etching solution, reacting at 400-600r/min under a water bath condition, centrifuging, washing with water, and freeze-drying to obtain accordion-shaped multilayer MXene powder; S2, adding the MXene powder prepared in the step S1 into an ammonium persulfate aqueous solution for micro-oxygen amorphization treatment, stirring at 300-500r/min, fully reacting, centrifuging, washing with water, and freeze-drying to obtain the crystalline/amorphous heterostructure composite material A/C-MXene.
  3. 3. The method for preparing the crystalline/amorphous heterostructure composite material according to claim 2, wherein the raw material Ti 3 AlC 2 in the step S1 is 1-3g, and the hydrofluoric acid etching solution is prepared by adding 10-40mL 8-12mol/L hydrochloric acid solution into 5-10mL hydrofluoric acid solution.
  4. 4. The method for preparing a crystalline/amorphous heterostructure composite material according to claim 2, wherein the reaction temperature is 35-50 ℃, the reaction time is 24-72 hours, and the pH is 6-7 by washing with water.
  5. 5. The method for preparing a crystalline/amorphous heterostructure composite material according to claim 2, wherein the freeze drying temperature in step S1 is-55±5 ℃ for 24±1h.
  6. 6. The method for preparing a crystalline/amorphous heterostructure composite material according to claim 2, wherein in the step S2, the mass of the MXene powder is 0.05-0.5g, the concentration of ammonium persulfate is 0.05-0.2mol/L, and the solution volume is 30-100mL.
  7. 7. The method of claim 2, wherein the reaction time in the step S2 is 30-72 h, and the pH is about 6-7.
  8. 8. The method for preparing a crystalline/amorphous heterostructure composite material according to claim 2, wherein the freeze drying temperature in step S2 is-55±5 ℃ for 24±1h.
  9. 9. The crystalline/amorphous heterostructure composite material of claim 1 or the method of preparation of any one of claims 2-8, which enhances dielectric polarization response capability of MXene nanoplatelets for use in absorption and/or conversion of electromagnetic waves.

Description

Preparation method and application of crystalline-amorphous heterostructure composite material Technical Field The invention relates to the field of electromagnetic microwave absorption of nanocomposite materials, in particular to a preparation method and application of a crystalline-amorphous heterostructure composite material. Background The wide use of wireless communication devices significantly improves the quality of life and work efficiency of people. However, with the rapid development of electromagnetic technology, electromagnetic radiation generated by electronic devices is becoming a fourth environmental pollution problem facing humans. The long-term exposure or working in high-intensity electromagnetic radiation environment not only generates potential harm to human health and ecological environment, but also affects the reliability and normal operation of precision electronic equipment. Meanwhile, the improvement of military radar detection technology makes the risk of being detected increasingly at the most advanced national defense equipment, and directly influences the battlefield viability of weapon equipment. This places higher demands on the stealth performance of the weapon equipment, and conventional stealth means have failed to meet the needs of complex electromagnetic environments and advanced detection techniques. Therefore, development of electromagnetic functional materials capable of effectively converting unnecessary electromagnetic waves and radar detection microwaves in composite materials is urgently needed, and efficient management of electromagnetic pollution and stealth of national defense weaponry are achieved. The electromagnetic wave absorbing material includes a magnetic material and a dielectric material. The magnetic absorber has the problems of high density, narrow absorption bandwidth and low response frequency, and limits the application of the magnetic absorber in the fields of electromagnetic wave absorption and protection. Dielectric materials have attracted considerable attention due to their stable physicochemical properties and tunable electronic structures. Therefore, the development of the high-performance dielectric electromagnetic wave absorbing material has potential application prospect in the fields of electromagnetic pollution and radar stealth. Based on the above, the invention provides a preparation method and application of a crystalline-amorphous heterostructure composite material. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a crystalline/amorphous heterostructure composite material and a preparation method and application thereof, and solves the technical problems of low absorption strength, poor impedance matching and narrow response wave band of the conventional dielectric electromagnetic wave absorption material. The crystalline/amorphous heterostructure composite material constructed by the invention has rich heterogeneous interfaces, the dielectric polarization response range of the material is improved, and the minimum reflection loss reaches-52.9 dB when the thickness is 2.5 mm. In one aspect, as shown in fig. 1-2, the present invention provides a crystalline/amorphous heterostructure composite material, wherein the crystalline/amorphous heterostructure composite material is a/C-MXene, and the crystalline/amorphous heterostructure composite material includes a controllable micro-oxygen amorphization conversion process of inducing a highly crystalline two-dimensional transition metal carbide T 3C2Tx MXene nano-sheet by using strong oxidizing property of ammonium persulfate, so as to form a nanocomposite material having a crystalline/amorphous heterostructure. The crystalline/amorphous heterostructure is formed by strong oxidative destruction of the ordered crystal structure of the MXene nanoplatelets by ammonium persulfate, forming a disordered crystal structure. And (3) performing micro-oxygen amorphization treatment on the multilayer MXene by taking ammonium persulfate as a strong oxidant to construct a crystalline/amorphous heterogeneous interface, enhancing dielectric polarization response capability of the MXene nano-sheet and promoting absorption and conversion of electromagnetic waves. On the other hand, as shown in fig. 3, the invention also provides a preparation method of the crystalline/amorphous heterostructure composite material, which comprises the following steps: S1, adding a two-dimensional lamellar transition metal carbide MAX phase Ti 3AlC2 raw material into hydrofluoric acid etching solution, reacting under a water bath condition, centrifuging, washing with water, and freeze-drying to obtain accordion-shaped multilayer MXene powder; S2, adding the MXene powder prepared in the step S1 into an ammonium persulfate aqueous solution for micro-oxygen amorphization treatment, stirring for full reaction, centrifuging, washing with water, and freeze-drying to obtain the crystalline/amorp