Core–Shell FeCoNi Nanoparticles in Carbon Aerogels for Highly Efficient Electromagnetic Wave Absorption

作者：Qingkun Xu, Xiaofen Li, Hantao He, Shuixiu Luo, Yi Yu, Zuzhou Xiong, Jüjun Yuan, Xianke Zhang, Xiaoqing Liu, Xiurong Zhu · 发表于：ACS Applied Nano Materials · 年份：2025 · DOI：10.1021/acsanm.5c00245 · 被引用次数：22 · 研究领域：Electromagnetic wave absorption materials、Advanced Antenna and Metasurface Technologies、Dielectric materials and actuators

Utilizing the multiple magnetic resonance properties of polymetallic alloys and considering the high electrical conductivity, porous structure, and high specific surface area of traditional phenolic-aldehyde-based carbon aerogels (CAs), ternary FeCoNi alloy nanoparticle-doped CAs (FeCoNi-CAs) with impressive core–shell structure were prepared via a simplified sol–gel method using 1,2-epoxypropane as a catalyst. The composition, conductivity, morphology, textural characteristics, electromagnetic wave absorption (EMA) properties and mechanisms, and radar cross-section (RCS) values of FeCoNi-CAs were first investigated in detail by adjusting the molar ratio of Fe, Co, and Ni elements. The results revealed that the optimum EMA properties occur at the molar ratio of Fe/Co/Ni = 4:1:5, and its corresponding Fe 4 Co 1 Ni 5 -CAs have a maximum effective absorption bandwidth (EAB max ) of 6.21 GHz (10.43–16.64 GHz) at a matching thickness of only 1.91 mm. Meanwhile, it possesses a minimum reflection loss (RL min ) of −54.9 dB and an EAB of 5.61 GHz (11.11–16.72 GHz) at the same matching thickness of only 1.87 mm in the medium- and high-frequency regions. The Fe 4 Co 1 Ni 5 -CAs also show the EAB max of 2.38 GHz (matching thickness: only 3.4 mm, 5.59–7.97 GHz) in the low-frequency region. Further analysis demonstrates that the excellent EMA performance of Fe 4 Co 1 Ni 5 -CAs is mainly ascribed to its higher conductivity stemming from its unique Fe/Co/Ni ratio. Not only does this ratio p...