Magnetic Field-Induced Porous Carbon Aerogel Supported CoFe Nanowires for Electromagnetic Wave Absorption

Abstract

Electromagnetic pollution has become an increasingly prominent environmental and engineering issue. To address this, this study employs eggplant-derived carbon as an aerogel matrix and utilizes a magnetic field-assisted method to synthesize CoFe alloy nanowires (NWs) in situ within it, constructing a networked interconnected composite structure. This structure forms a continuous and uniform three-dimensional (3D) conductive network, achieving highly efficient synergistic magnetic and conductive losses. Building upon this foundation, a high-performance electromagnetic wave absorber (EMA) material has been successfully developed that combines lightweight properties, strong absorption capabilities, and structural functionality. By controlling the temperature during carbon thermal reduction, the microstructure of the alloy nanowires can be effectively regulated, enabling precise optimization of their EMA performance. At a heat treatment temperature of 800°C, the prepared CoFe NWs@porous carbon aerogel exhibited the most outstanding absorptive performance: minimum reflection loss as low as -64.6 dB and maximum effective absorption bandwidth reaching 7.8 GHz. This performance primarily stems from the synergistic interaction between the material's unique 3D carbon framework structure and the uniformly distributed nanowire network on its surface, achieving excellent impedance matching and strong attenuation capabilities. Additionally, this aerogel possesses extremely low density and outstanding thermal insulation properties, significantly suppressing heat transfer. As a sustainable material integrating strong absorption, wide bandwidth, lightweight properties, and superior thermal management, it demonstrates broad application prospects in next-generation communications and defense technology fields.