Improved impedance matching by multi-componential metal-hybridized rGO toward high performance of microwave absorption

David Hui,Jinyang Li,Hunan Jiang,Fei Huang,Jinlong Xie,Yifan Guo,Dan Gao,Zuowan Zhou,Ahsan Zaman,Xingxing Chen

doi:10.1515/ntrev-2021-0001

Abstract

Abstract Microwave-absorbing materials with good microwave absorption performance are of great interest for military applications and human health, which is threatened by electromagnetic radiation pollution. Herein, the design and synthesis of multi-componential metal-hybridized graphene composites via freeze drying and pyrolysis of ferrocene hydrazone complex precursor are reported. Various magnetic nanoparticles are loaded on reduced graphene oxide (rGO) via controlling their pyrolysis temperature. The complex electromagnetic parameters of these hybrids are therefore regulated by the hybrid components. Among them, rGO hybridized by the sea-island-like Fe2O3/Fe3O4/FeNi3 multi-componential metals shows a good balance of dielectric and magnetic constants. Thus, the improved impedance matching with free space brings about a superior electromagnetic wave absorption performance, especially on the effective absorption bandwidth. The minimum reflection loss (RL) of the hybrids is as low as −40.3 dB at 11 GHz with the RL bandwidth of −10 dB being 4.55 GHz (from 9.25 to 13.8 GHz).

Highlights

The rapid growth of modern technologies promotes the applications of electronic devices, providing convenience to human lives or military equipment
A series of multi-component metal (McM)@reduced graphene oxide (rGO) annealed at different temperatures are synthesized to recognize their structural differences
The ferrocene hydrazone condensates (Fc)–Ni attached on the surface of graphene oxide (GO) decomposes into nanoparticles and annealing temperatures remarkably influence the structures of decomposed particles

Summary

Introduction

The rapid growth of modern technologies promotes the applications of electronic devices, providing convenience to human lives or military equipment. The mismatched dielectric constant and permeability, namely, impedance mismatching that exists in most materials, always lead to a narrow absorbing bandwidth In this regard, the componential and structural design of materials has aroused the enthusiasm toward good MA performance with broad absorption bandwidth. Co/rGO is synthesized by hydrothermal method [19], and Fe-hybridized rGO is achieved through primitive chemical reduction [20] These hybrids exhibit improved but uncontrollable MA performances due to the single component of magnetic particles [21,22]. Compared with the existing methods, pyrolyzing bimetallic precursor is able to achieve a controllable McM@rGO hybrid by tuning the annealing temperature The relationships between their MA performances and structure are systematically studied, which provides a meaningful perspective for the componential and structural design of McM-hybridized graphene toward high MA performances

Synthesis of Fc–Ni derivatives

Synthesis of multi-componential metal-hybridized rGO

Materials

Synthesis of ferrocene hydrazone condensates

Characterization

Results and discussion

Conclusions