A hierarchical SiCnw@SiC aerogel decorated with Ni-capped carbon nanotubes toward high-performance electromagnetic wave absorber
Jun He, Yanwei Zhang, Kechao Zhou, Haitang Yang, Heng Luo, Yang Li
Abstract
Increasing attention has been paid to the regulation of electromagnetic parameters by reasonable micromorphological design and proper composition to realize high-performance electromagnetic wave absorbers. Herein, a unique hierarchical SiC nanowire-reinforced SiC aerogel decorated with Ni-capped carbon nanotubes (SiCnw@[email protected]) was constructed. The effective synergism between the combination of multiphase magnetic/dielectric materials and the introduction of specific 3D hierarchical microstructures is beneficial for the apparent improvement of multiple dielectric/magnetic losses, electromagnetic scattering effects, and impedance matching capabilities, exhibiting remarkable tunable microwave absorption performance. Accordingly, a strong microwave absorption intensity (RLmin) at 10.24 GHz of −47.75 dB with a loading of 20 wt% and an ultrawide effective absorption bandwidth (EAB, RL < −10 dB) of 8.96 GHz (9.04–18.0 GHz) at only 30 wt% filler loading and thin 2.0 mm thickness are realized. This work provides valuable guidance for the design of multiphase magnetic/dielectric absorbers with hierarchical microstructures and extends the study of advanced microwave absorption materials with the advantages of light weight, minimal thickness, strong RL and broad EAB.