Ultralight MOF-Derived Ni3S2@N, S-Codoped Graphene Aerogels for High-Performance Microwave Absorption.

Wenjing Yu,Bo Liu,Xiaojiao Zhao

doi:10.3390/nano12040655

Abstract

To develop high-performance microwave absorption materials with the features of lightweight, thin thickness, broad bandwidth, and strong absorption, an ultralight Ni3S2@N, S-codoped graphene aerogel with a density of 13.5 mg/cm3 has been fabricated by the use of metal-organic frameworks (MOFs) to directly initiate the gelation of graphene oxide strategy. In such a strategy, dual-functional 1D Ni-MOF nanorods not only act as the gelation agent but also afford the doping elements (N and S) originated from the organic species and the precursor for metal sulfide. Due to the synergistic effects of good impedance matching and multiple losses, the optimal reflection loss (RL) of as-prepared Ni3S2@N, S-codoped graphene aerogel reaches −46.9 dB at 17.1 GHz with only 2.0 mm and ultralow filling content (1.75 wt%). The maximum effective absorption bandwidth (EAB) reaches 6.3 GHz (11.7–18.0 GHz) at 2.38 mm, covering the whole Ku band. Moreover, the value of EAB with the RL less than −30 dB can be tuned to 12.2 GHz (5.8–18 GHz) at the absorber thickness ranging from 1.9 to 5.0 mm. This work provides insight for rational design and fabrication of multicomponent-containing graphene aerogels, showing the potential application in lightweight and high-performance microwave absorption.

Highlights

Graphene aerogels (GAs) offer a distinctive combination of high porosity, low density, and tunable conductive properties, which make it grab considerable attention in various applications [1,2,3,4,5], in particular for high-performance electromagnetic (EM) wave-attenuation [6,7,8]
Based on the aforementioned discussion, the high-performance microwave absorption property of as-prepared Ni3 S2 @NSGA-650 is attributed to the synergistic effects of good impedance matching and multiple losses, which can be revealed from the perspective of the multiscale
A high-performance Ni3 S2 @N, S-codoped graphene aerogel-based microwave absorber has been fabricated by a facile approach based on 1D Ni-metal-organic frameworks (MOFs) nanorods directly induced gelation strategy

Summary

Introduction

Graphene aerogels (GAs) offer a distinctive combination of high porosity, low density, and tunable conductive properties, which make it grab considerable attention in various applications [1,2,3,4,5], in particular for high-performance electromagnetic (EM) wave. To further improve the microwave attenuation, the graphene-based aerogels integrated with multiple effects, including conductive loss, dipole polarization, interfacial polarization, magnetic loss, and multiple scattering and reflection have been developed [13,20,21,22,23]. Chen et al reported a multi-component N-doped graphene aerogel containing N-doped carbon nanotubes and FeNi nanoparticles, which exhibits a strong microwave attenuation (−39.39 dB) of thin thickness (2.0 mm) [21]. Another typical example is multi-dimensional gradient graphene aerogels, comprising 3D carbon nanocoils, 2D graphene sheets, 1D carbon nanofiber, and 0D Fe3 O4 @C nanoparticles. The presented MOF-induced gelation strategy provides an effective pathway to fabricate multicomponent absorbers with a 3D porous structure for achieving excellent EM absorption performance

Preparation of Ni-MOF

Characterization

Figure

Comparison of EM absorption between

EM Absorption Mechanism

Conclusions