Super-light Cu@Ni nanowires/graphene oxide composites for significantly enhanced microwave absorption performance

Xiaoxia Wang,Wei Zhang,Mingxun Yu,Xueying Cao,Liang Cui,Jingquan Liu,Baoqin Zhang

doi:10.1038/s41598-017-01529-2

Abstract

Graphene oxide (GO) was rarely used as microwave absorption (MA) material due to its lower dielectric loss compared with reduced GO (RGO). However, the characteristics of low conductivity, light weight, and large surface area were beneficial to the impedance matching for absorbers already containing highly conductive metal materials. Cu@Ni nanowires are promising MA materials due to the desired dielectric loss from copper and excellent magnetic loss from nickel. However, the high density was an impediment to its further application. Combining Cu@Ni nanowires with GO should be an effective solution to decrease the absorber’s density and improve its MA properties. Herein, we demonstrated that Cu@Ni nanowires/GO composites exhibited enhanced MA capacities compared with Cu@Ni nanowires or GO alone, and the minimum reflection loss reached −42.8 dB at 16.9 GHz with a thickness of 2.1 mm. The enhanced MA performance mainly originated from good impedance matching, as a result of the addition of low conductivity of GO. To confirm this point, the MA performance of Cu@Ni nanowires/RGO was studied, and unsurprisingly, weak MA performance was obtained. Our work provides a new strategy to decrease the density, broaden the frequency band and tune MA performance of composites.

Highlights

The increasing demand for microwave absorption (MA) materials with high efficiency, broad-bandwidth, and lightweight have attracted considerable attentions due to the serious electromagnetic interference (EMI) problems, which origin from the rapid advancement of electronic instruments, such as local area networks, electronic devices, and wireless communication tools[1, 2]
Low-dimensional carbon materials, like carbon nanotubes (CNTs)[11] and reduced graphene oxide (RGO)[12] were widely investigated as MA materials owing to their high dielectric loss, large surface areas, obvious anisotropy, good thermal and mechanical properties[13, 14], while graphene oxide (GO) was rarely used due to its low conductivity[15]
The MA performance and mechanisms of the as-prepared Cu@Ni NWs/GO composites were investigated in detail, and the results revealed that the good complement between relative permittivity and permeability should be the main contribution to the enhanced MA performance of Cu@Ni NWs/GO composites

Summary

Introduction

The increasing demand for microwave absorption (MA) materials with high efficiency, broad-bandwidth, and lightweight have attracted considerable attentions due to the serious electromagnetic interference (EMI) problems, which origin from the rapid advancement of electronic instruments, such as local area networks, electronic devices, and wireless communication tools[1, 2]. Low-dimensional carbon materials, like carbon nanotubes (CNTs)[11] and reduced graphene oxide (RGO)[12] were widely investigated as MA materials owing to their high dielectric loss, large surface areas, obvious anisotropy, good thermal and mechanical properties[13, 14], while graphene oxide (GO) was rarely used due to its low conductivity[15]. It is well known low conductivity corresponds to low dielectric loss, and leads to poor MA performance. The MA performance and mechanisms of the as-prepared Cu@Ni NWs/GO composites were investigated in detail, and the results revealed that the good complement between relative permittivity and permeability should be the main contribution to the enhanced MA performance of Cu@Ni NWs/GO composites

Methods

Results

Conclusion