Joule-Heating-Driven Synthesis of a Honeycomb-Like Porous Carbon Nanofiber/High Entropy Alloy Composite as an Ultralightweight Electromagnetic Wave Absorber

Abstract

High entropy alloys (HEA) have garnered significant attention in electromagnetic wave (EMW) absorption due to their efficient synergism among multiple components and tunable electronic structures. However, their high density and limited chemical stability hinder their progress as lightweight absorbers. Incorporating HEA with carbon offers a promising solution, but synthesizing stable HEA/carbon composite faces challenges due to the propensity for phase separation during conventional heat treatments. Moreover, EMW absorption mechanisms in HEAs may be different from established empirical models due to their high-entropy effect. This underscores the urgent need to synthesize stable and lightweight HEA/carbon absorbers and uncover their intrinsic absorption mechanisms. Herein, we successfully integrated a quinary FeCoNiCuMn HEA into a honeycomb-like porous carbon nanofiber (HCNF) using electrostatic spinning and the Joule-heating method. Leveraging the inherent lattice distortion effects and honeycomb structure, the HCNF/HEA composite demonstrates outstanding EMW absorption properties at an ultralow filler loading of 2 wt %. It achieves a minimum reflection loss of −65.8 dB and boasts a maximum absorption bandwidth of up to 7.68 GHz. This study not only showcases the effectiveness of combining HCNF with HEA, but also underscores the potential of Joule-heating synthesis for developing lightweight HEA-based absorbers.

Stimulating Electron Delocalization of Lanthanide Elements through High-Entropy Confinement to Promote Electrocatalytic Water Splitting

“…The entropy values for the prepared electrocatalyst have been supplemented in the revised manuscript. According to previous literature reports, the calculation of entropy can be achieved by − where R is the molar gas constant and x represents the total mole constant of the elemental component.…”

Carbon carrier-based rapid Joule heating technology: a review on the preparation and applications of functional nanomaterials

“…Additionally, research has indicated that Joule heating can be utilized in the synthesis of high-entropy alloys and carbon composites, resulting in materials that exhibit excellent electromagnetic wave absorption. 106 Consequently, in the field of EMI shielding and microwave absorption material preparation, CJH technology can enhance the conductivity of the material, optimise the structure of its carbon-based nano-part, endow the material with abundant defects and pore structures, and increase the specific surface area of the material, thus enhancing its ability to scatter or absorb electromagnetic waves.…”