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CN-117446792-B - Fe/N co-doped hollow carbonaceous nanosphere-loaded graphene aerogel surface wave-absorbing material and preparation method thereof

CN117446792BCN 117446792 BCN117446792 BCN 117446792BCN-117446792-B

Abstract

The invention discloses a graphene aerogel surface wave-absorbing material loaded with Fe/N co-doped hollow carbon nanospheres and a preparation method thereof, firstly, graphene oxide is used as a raw material to prepare reduced graphene oxide aerogel, and preparing hollow Fe 3 O 4 magnetic nano particles by taking FeCl 3 ·6H 2 O and ammonium acetate as raw materials through a hydrothermal method, preparing Fe 3 O 4 /PPy/reduced graphene oxide aerogel through an in-situ polymerization method, and preparing the Fe/N co-doped hollow carbon nano sphere loaded graphene aerogel through high-temperature heat treatment. The graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbonaceous nanospheres has excellent dielectric loss and magnetic loss, and meanwhile, the magnetic Fe nano particles in the material can well realize electromagnetic wave energy conversion, can obtain excellent microwave absorption performance, and has great potential in the advanced nanocomposite of the new generation.

Inventors

  • WANG CHUAN

Assignees

  • 维特瑞交通科技有限公司

Dates

Publication Date
20260505
Application Date
20231107

Claims (8)

  1. 1. The preparation method of the Fe/N co-doped hollow carbonaceous nanosphere-loaded graphene aerogel surface wave-absorbing material is characterized by comprising the following preparation steps: the preparation method comprises the steps of (1) dispersing graphene oxide and a reducing agent into a mixed solution of deionized water and ethanol for reduction reaction to obtain reduced graphene oxide hydrogel, (2) placing the reduced graphene oxide hydrogel in a freeze dryer for freeze drying to obtain reduced graphene oxide aerogel; Dissolving FeCl 3 ·6H 2 O in glycol and performing ultrasonic treatment to form transparent yellow solution, adding ammonium acetate into the transparent yellow solution and performing continuous ultrasonic treatment for 1h, transferring the transparent yellow solution into a stainless steel autoclave with a tetrafluoroethylene lining, heating at 200 ℃ for 8 hours to obtain black precipitate, centrifuging and washing with ethanol for three times, and vacuum drying at 60 ℃ to obtain hollow Fe 3 O 4 nano particles, wherein the mass ratio of FeCl 3 ·6H 2 O to ammonium acetate is 1:2-1:5; The preparation method of the Fe 3 O 4 /PPy/reduced graphene oxide aerogel comprises the steps of dispersing the reduced graphene oxide aerogel in deionized water for 1h, adding hollow Fe 3 O 4 nano particles, performing ultrasonic dispersion for 1h, dropwise adding pyrrole monomer Py under ultrasonic treatment, adding hydrochloric acid for 1mol/L to enable the dispersion liquid to be acidic, continuing ultrasonic treatment for 2h to ensure that pyrrole completely covers the outer surface and the inner surface of the hollow Fe 3 O 4 nano sphere, cooling to room temperature after the reaction is finished, centrifugally washing the product with ethanol for three times, and drying in a vacuum oven at 60 ℃ for 12h to obtain the Fe 3 O 4 /PPy/reduced graphene oxide aerogel, wherein the mass ratio of the reduced graphene oxide aerogel, the hollow Fe 3 O 4 nano particles and the pyrrole monomer Py is 100 (5-10); And 4, preparing the Fe/N co-doped hollow carbonaceous nanospheres, namely placing the Fe 3 O 4 /PPy/reduced graphene oxide aerogel prepared in the step 3 into a tubular furnace for heat treatment, and obtaining the Fe/N co-doped hollow carbonaceous nanospheres graphene aerogel in the heat treatment process.
  2. 2. The method for preparing the graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbon nanospheres according to claim 1, wherein the volume ratio of deionized water to ethanol in the mixed solution in the step 1 is 3:1-5:1.
  3. 3. The method for preparing the graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbonaceous nanospheres according to claim 1, wherein the reducing agent in the step 1 is one or more of sodium bisulfite, ascorbic acid, thiourea, sodium sulfide and hydrazine hydrate, and the mass ratio of graphene oxide to the reducing agent is 1:1-1:6.
  4. 4. The method for preparing the graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbon nanospheres according to claim 1, wherein the reduction reaction in the step 1 is performed at a temperature of 80-100 ℃ for 6-12 hours.
  5. 5. The method for preparing the graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbon nanospheres according to claim 1, wherein the freeze-drying temperature in the step 1 is-20 ℃ to-100 ℃ and the freeze-drying time is 5-48 h.
  6. 6. The method for preparing the graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbon nanospheres according to claim 1, wherein the heat treatment condition in the step 4 is that the temperature is raised to 600-800 ℃ under the protection of inert gas, and the heat treatment time is 4-6 h.
  7. 7. The method for preparing the graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbon nanospheres according to claim 6, wherein the inert gas is one of nitrogen, argon and radon.
  8. 8. The graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbonaceous nanospheres prepared by the preparation method according to any one of claims 1-7.

Description

Fe/N co-doped hollow carbonaceous nanosphere-loaded graphene aerogel surface wave-absorbing material and preparation method thereof Technical Field The invention relates to the technical field of functional materials, in particular to a graphene aerogel surface wave-absorbing material loaded with Fe/N co-doped hollow carbon nanospheres and a preparation method thereof. Background With the development of the electronic communication industry, electromagnetic waves are ubiquitous as a basic means of wireless communication, and thus the problem of electromagnetic pollution is also becoming more serious. In addition, the electromagnetic stealth technology in the military field is used as an effective means for improving the survival, burst prevention and deep striking capability of a weapon system, and has become one of hot spots of each military high and new technology, so that the electromagnetic wave absorbing material is not only used as a common material in the field of electromagnetic emission and reception, but also used as an important material for realizing radar stealth function of aircrafts, military ships, military combat vehicles and field facilities, Is gradually becoming a hot spot for research in the field of functional materials. The current domestic and foreign wave-absorbing materials mainly comprise iron wave-absorbing materials, carbon wave-absorbing materials, ceramic wave-absorbing materials and the like, wherein the iron wave-absorbing materials lose magnetism at high temperature to lose wave-absorbing performance, meanwhile, the iron wave-absorbing materials have large mass specific gravity and poor corrosion resistance to limit the application range, the ceramic wave-absorbing materials are not suitable for wide application due to large weight, and the carbon wave-absorbing materials have the advantages of light weight, good electric conductivity and the like, so that the iron wave-absorbing materials become the most widely applied electromagnetic wave-absorbing materials. Among the carbon-based wave-absorbing materials, the three-dimensional porous structure of the graphene aerogel wave-absorbing material formed by cross-linking graphene sheets has been proved to be a wave-absorbing material with development prospect because of low density, light weight, corrosion resistance, large specific surface area and excellent conductivity, and the material can generate dielectric loss under a high-frequency electromagnetic field so as to consume electromagnetic waves. However, due to the single composition, the wave absorbing performance needs to be further improved due to the lack of a polarization loss mechanism. The graphene aerogel wave-absorbing material with excellent wave-absorbing performance can be obtained by combining magnetic loss and dielectric loss through compositing with other materials, such as magnetic nanoparticles, polymer molecules and the like. Disclosure of Invention The invention provides a graphene aerogel surface wave-absorbing material loaded with Fe/N co-doped hollow carbon nanospheres and a preparation method thereof, and aims to provide a high-performance wave-absorbing material for solving the problems caused by electromagnetic wave application. In order to achieve the aim, the invention provides the following technical scheme that the preparation method of the graphene aerogel surface wave-absorbing material loaded with the Fe/N co-doped hollow carbon nanospheres comprises the following preparation processes: the preparation method comprises the steps of (1) dispersing graphene oxide and a reducing agent into a mixed solution of deionized water and ethanol for reduction reaction to obtain reduced graphene oxide hydrogel, (2) placing the reduced graphene oxide hydrogel in a freeze dryer for freeze drying to obtain reduced graphene oxide aerogel; Dissolving FeCl 3·6H2 O in glycol and performing ultrasonic treatment to form transparent yellow solution, adding ammonium acetate into the transparent yellow solution and performing continuous ultrasonic treatment for 1h, transferring the transparent yellow solution into a stainless steel autoclave with a tetrafluoroethylene lining, heating at 200 ℃ for 8 hours to obtain black precipitate, centrifuging and washing with ethanol for three times, and vacuum drying at 60 ℃ to obtain hollow Fe 3O4 nano particles; Dispersing the reduced graphene oxide aerogel into deionized water, performing ultrasonic dispersion for 1h, adding hollow Fe 3O4 nano particles, performing ultrasonic dispersion for 1h, dropwise adding pyrrole monomer (Py) under ultrasonic treatment, adding hydrochloric acid (1 mol/L) to make the dispersion acidic, continuing ultrasonic treatment for 2h to ensure that pyrrole completely covers the outer surface and the inner surface of the hollow Fe 3O4 nano sphere, cooling to room temperature after the reaction is finished, centrifugally washing the product with ethanol for three times, and drying in a vacuum oven