Synergistic effects of yolk-shell and nanopore architectures on the microwave absorption performance of Co@void@C nanocomposites

Abstract

Due to deficiencies of poor dielectric loss and narrow absorption bandwidth, how to improve the performance of cobalt-based absorbers remains a challenge in the field of microwave absorption materials. In this work, a convenient and efficient strategy combining hydrogen plasma-metal reaction (HPMR) and chemical dealloying has been developed for the fabrication of nanoporous Co@void@C nanocomposites (NCs). The performance exhibits apparent enhancement owing to the synergistic effects of yolk-shell and nanopore architectures. The minimum reflection loss (RLmin) value reaches −19.5 dB at the thickness of 1.6 mm and the effective absorption bandwidth (EAB, RL ≤ −10 dB) goes up to 6.8 GHz at the thickness of 1.9 mm. For comparison, the porous Co@C NCs with only nanopore architecture have a narrow EAB of 2.6 GHz and Co@void@C NCs with only yolk-shell architecture cannot effectively absorb the incident microwave (RL > −10 dB) within 2–18 GHz. The novel Co-based absorber with yolk-shell and nanopore architectures possesses great potential for the application in microwave absorption field.