Multiscale collaborative coupling of wood-derived porous carbon modified by three-dimensional conductive magnetic networks for electromagnetic interference shielding

Abstract

The contribution of shielding materials to electromagnetic interference (EMI) shielding can be divided into reflection loss and absorption loss, but the mechanism of how to coordinate their balance is ambiguous in previous studies. To this end, we propose a strategy to prepare conductive magnetic networks consisting of N-doped carbon nanotubes (NCNTs) and Ni nanoparticles in carbonized wood (CW) by chemical vapor-phase catalysis. The multi-scale collaborative coupling effect of micron-scale skeleton channels, nano-scale network gaps and atomic-scale elemental doping achieves the matching of the above two electromagnetic losses. The optimized Ni@NCNT/CW composite exhibits an average EMI shielding effectiveness (EMI-SE) of 73.7 dB with ultra-low density (0.541 g/cm3) across the entire X-band (8.2–12.4 GHz), as well as fine hydrophobicity (118.6°) and fire resistance. Meanwhile, in the electromagnetic attenuation capability simulation, the absorption-reflection ratio changes from absorption-dominated to reflection-dominated with the change of structural scale, which is highly consistent with the experimental test trend. This research proposes a novel insight that multiscale collaborative coupling is an effective strategy to coordinate and optimize the shielding combination mechanism.