Morphology engineering of defective graphene for microwave absorption

Graphene with abundant defects has been considered as the most lightweight electromagnetic functional materials. Although important, the dominant electromagnetic response of defective graphene with diverse morphologies is rarely the focus of existing research. Herein, the defective graphene with two-dimensional planar structure (2D-ps) and three-dimensional continuous network (3D-cn) morphologies were dexterously designed with 2D mixing and 3D filled systems of polymeric matrix. A comparison between the topologies of defective graphene-based nanofillers and the microwave attenuation behav-iors was examined. Defective graphene with 3D-cn morphology can achieve ultralow filling content and broadband absorption, which is attributed to the presence of numerous pore structures that promote impedance matching, induce continuous conduction loss and provide multiple reflection and scattering sites for electromagnetic wave attenuation. Comparatively, by virtue of the increased filling content of 2D-ps, the dielectric losses primarily originate from the dielectric genes, including aggregation -induced-charge transport, abundant defect and dipole polarization, resulting in good microwave absorp-tion at low thickness and low frequency. Therefore, this work provides a pioneering insight into morphol-ogy engineering of defective graphene microwave absorbers, and it will guide future exploration of customizing high-performance microwave absorption materials based on graphene-based low -dimensional building blocks.(c) 2023 Elsevier Inc. All rights reserved.

Automated summary

This study designs defective graphene with two-dimensional planar structure and three-dimensional continuous network structure, and compares their performance in microwave attenuation. Defective graphene with three-dimensional continuous network structure exhibits characteristics of ultra-low filling content and broadband absorption, while defective graphene with two-dimensional planar structure shows good microwave absorption performance at low thickness and low frequency.