Self-assembled reduced graphene oxide/nickel nanofibers with hierarchical core-shell structure for enhanced electromagnetic wave absorption

摘要

In this study, self-assembled three-dimensional (3D) reduced graphene oxide/nickel (rGO/Ni) nanofibers with hierarchical core-shell structure and vertically aligned graphene edge planes are synthesized as an efficient microwave absorption material. Electromagnetic multifunctional Ni chains form the skeleton of 3D nanofibers, and 2D rGO nanosheets are wrapped around the 1D Ni chain to form 3D rGO/Ni nano fibers via electrostatic self-assembly combined with a reduction method. Compared with the pristine Ni chain or rGO sheet, the unique vertically aligned graphene edge plane gives the 3D rGO/Ni nanofiber a much larger specific surface area and interlaced area between the 3D nanofibers. The hierarchical core shell structure also provides abundant interfaces between the rGO and Ni chains, giving the 3D rGO/Ni nanofibers effective interfacial polarization loss. As a result, the 3D rGO/Ni nanofibers exhibit excellent microwave absorption properties. At a thickness of 2 mm, the minimum reflection loss of the nanofibers with only 15 wt% loading in paraffin reaches-50.52 dB, and the effective absorption bandwidth achieves 4.2 GHz. Moreover, the 3D rGO/Ni nanofibers also exhibit excellent dispersibility because of their special edge plane structure. This work provides an effective strategy for designing high-performance microwave absorption materials and is promising for applications in efficient electronics protection. (C) 2020 Elsevier Ltd. All rights reserved.