Constructing two-dimensional lamellar monometallic carbon nanocomposites by sodium chloride hard template for lightweight microwave scattering and absorption

Abstract

Low-dimensional carbon matrix nanocomposites are promising for lightweight and efficient electromagnetic wave absorption considering their large specific surface area and the multi-interface interaction. However, it remains a challenge to maintain the uniform dispersion of magnetic nanoparticles, which plays a vital role in regulating both dielectric and magnetic loss abilities. In this paper, by sodium chloride (NaCl) hard template, two-dimensional (2D) lamellar Co/C (NCC) and Fe/C (NFC) nanocomposites with well dispersed magnetic nanocomposites are prepared consecutively. An in-depth study of the construction of 2D lamellar structure on the electromagnetic dissipation and impedance matching has been carried out. The result shows that the 2D lamellar NCC and NFC prepared by NaCl hard template own the higher degree of graphitization and dielectric loss than those three-dimensional (3D) bulk composites without the addition of NaCl. Furthermore, the series of 2D lamellar nanocomposites exhibit excellent microwave absorption properties. The minimum reflection loss (RL) value of NCC and NFC can reach −52.2 and −46.7 dB, respectively. Particularly, accompanied by the thin thickness of only 2.0 mm, the effective absorption bandwidth (EAB, RL ≤ −10 dB) of NFC can reach 5.4 GHz (11.5–16.9 GHz). Furthermore, the smallest RCS value of only −8.098 dBm2 for NFC under vertical incidence can be obtained for excellent electromagnetic wave scattering and absorption.