In-situ construction of nitrogen-doped reduced graphene oxide@carbon nanofibers towards the synergetic enhancement of their microwave absorption properties via integrating point defects and structure engineering

The aim of this work is to develop materials that can absorb microwave to meet the requirements of stealth technology and solve the problem of electromagnetic pollution. However, the challenge is having materials with high-efficient absorption properties at an ultralow filling rate and visualizing the micro-wave response. The strategy used in this work was to integrate point defect and microstructure in preparing materials, nitrogen-doped reduced graphene oxide@ carbon nanofibers with high-efficient microwave absorption and double-layered structure. Ethylenediamine (nitrogen source), was doped into the materials, resulting in the generation of the defects. The microwave absorption performance of the materials was affected by the degree of defects due to the dipole polarization loss and conductive loss. The optimal samples gained the maximum reflection loss of -54.7 dB and effective absorption bandwidth of 4.74 GHz at a filling rate of only 8 wt%. More significantly, the microwave absorbing mechanism was analyzed visually in the response field. Furthermore, the actual stealth effects were evaluated by the radar cross section reduction, and the value was 29.2 dBm(2). The experimental results illustrated that nitrogen-doped reduced graphene oxide@ carbon nanofibers may be alternative materials with high microwave absorption performance at a low filling rate. (C) 2022 Elsevier Inc. All rights reserved.

Automated summary

This work aims to develop materials that can absorb microwave to fulfill the requirements of stealth technology and address the issue of electromagnetic pollution. By integrating point defect and microstructure, nitrogen-doped reduced graphene oxide@ carbon nanofibers with high-efficient microwave absorption and double-layered structure were prepared. The optimal samples achieved a maximum reflection loss of -54.7 dB and an effective absorption bandwidth of 4.74 GHz at a low filling rate of 8 wt%. Moreover, the microwave absorbing mechanism was visually analyzed in the response field.