Construction of 1D Heterogeneous Co/C@Ag Nws With Tunable Electromagnetic Wave Absorption And Shielding Performance

In this study, silver nanowires (Ag NWs) are synthesized at first, and then the 1D heterogeneous Co/C@Ag NWs with a kebab- and popsicle-like microstructures are constructed by in situ growth ZIF-67 on Ag NWs combined with calcination. Results show that the EM wave prevention performance of composites depends on the loading of Co/C particles threaded on the Ag NWs. The popsicle-like structure with high Co/C loading gives Co/C@Ag NWs excellent EM wave absorption performance, which achieved a minimum reflection loss (RL_min) of −44.5 dB with a low filling of 30 wt.% in paraffin; while the kebab-like structure with low Co/C loading shows good electromagnetic interference (EMI) shielding effectiveness (SE_T) of 30.2 dB at the same filler ratio. The enhanced EM wave absorption performance is attributed to the synergy of multiple energy dissipation mechanisms including dielectric loss, magnetic loss, polarization loss, eddy-current loss, multiple reflection loss, as well as proper impedance matching; the good EMI shielding performance is mainly due to the conduction loss brought by the Ag NWs with ultrahigh conductivity. This work provides a reference for the design of electromagnetic wave prevention material with tuned absorption and shielding performance.