Lightweight, Low-Cost Co2SiO4@diatomite Core-Shell Composite Material for High-Efficiency Microwave Absorption.

Yifan Zhang,Xiaohan Huang,Yuntao Xiao,Zhaohui Liu,Tao Sun,Hao Teng,Qing Sun,Rui Cai,Kexin Yao,Yuxin Zhang,Pingan Yang,Kailin Li,Dashuang Wang

doi:10.3390/molecules27031055

Abstract

The porous and biomimetic cobalt silicate@diatomite (Co2SiO4@diatomite) was successfully synthesized by a two-step method, including the hydrothermal method and calcination to improve the electromagnetic wave absorption property. Different hydrothermal times were well-tuned for Co2SiO4@diatomite composites with different loadings of Co2SiO4. Interestingly, the Co2SiO4@diatomite composites (6 h, 25 wt%) had a smaller minimum reflection loss. Moreover, the minimum reflection loss (RLmin) could reach −12.03 dB at 16.64 GHz and the matched absorber thickness was 10 mm, while the effective absorption bandwidth (EAB, RL ≤ −10 dB) could be 1.92 GHz. In principle, such findings indicate that Co2SiO4@diatomite nanocomposites could be a promising candidate for high-efficiency microwave absorption capability.

Highlights

In recent year, with the rapid development of electronic technology, electromagnetic (EM) pollution has become a non-negligible problem
Carbon materials and conductive polymers have the disadvantages of impedance mismatching and narrow effective absorption bandwidth, and metal oxides suffer from gravimetric density and poor corrosion resistance [23]
Cobalt nitrate hexahydrate (Co(NO3)2·6H2O) and diatomite were purchased from Shanghai Aladdin Biochemical Technology Co., Ltd. (Shanghai, China) Ammonium fluoride (NH4F) and urea were purchased from ChengDu Chron Chemicals Co., Ltd. (Chengdu, China)

Summary

Introduction

With the rapid development of electronic technology, electromagnetic (EM) pollution has become a non-negligible problem. Conductive polymers, such as polypyrrole [17] and polypyrrole@PANI [18], are of good conductivity, which induces the strong permittivity response by dielectric interaction to absorb EMW [19] Metallic oxides, such as NiCo2O4 [20], Mn3O4 [21], CuCo2O4-CuO composites [22], and Co1.29Ni1.71O4 [8], have good magnetic loss characteristics, considered as excellent candidates for EMWAMs. carbon materials and conductive polymers have the disadvantages of impedance mismatching and narrow effective absorption bandwidth, and metal oxides suffer from gravimetric density and poor corrosion resistance [23].

Materials

Synthesis

Conclusions