Hierarchical, seamless, edge-rich nanocarbon hybrid foams for highly efficient electromagnetic-interference shielding

Lightweight, flexible, ultrahigh-performance electromagnetic-interference (EMI) shielding materials are urgently required in the areas of aircraft/aerospace, portable and wearable electronics. Herein, 1D carbon nanotubes (CNT) and carbon nanofibers (CNF) with 2D edge-rich graphene (ERG) are used to form a lightweight, flexible CNT-ERG-CNF hybrid foam. This foam was fabricated through a self-sacrificial templating chemical vapor deposition process, where nanocarbons bond through covalent bonding, forming a hierarchical 3D hybridized carbon nanostructure. Multistage conductive networks and heterogeneous interfaces were constructed using edge-rich nanocarbons to increase the induced currents and interfacial polarization which makes great contributions to achieve high absorption electromagnetic shielding effectiveness (SEA). The CNT-ERG-CNF hybrid foam exhibits EMI shielding effectiveness (SE) exceeding 55.4 dB in the X-band while the specific SE (SSE, SE divided by mass density) achieves 9200 dB cm(3) g(-1), which surpasses that of nearly all other carbon-based composite materials. Furthermore, the structural stability and durability of the flexible CNT-ERG-CNF hybrid foams is examined by measuring EMI SE after 10000 times cyclic bending. Remarkably, this work not only provides a new idea for preparing hierarchical carbon materials for a wide range of applications, but presents some fundamental insights for achieving higher absorption losses in EMI shielding materials. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

In this study, a lightweight, flexible CNT-ERG-CNF hybrid foam with ultrahigh electromagnetic interference (EMI) shielding effectiveness was fabricated using carbon nanotubes, carbon nanofibers, and edge-rich graphene. The foam demonstrated EMI shielding effectiveness exceeding 55.4 dB in the X-band and specific SE reaching 9200 dB cm(3) g(-1), surpassing other carbon-based composite materials. Additionally, the structural stability and durability of the foam was examined after 10000 times cyclic bending, showing promising results for practical applications.