In-Situ Growth of Carbon Nanotubes on MOF-Derived High-Entropy Alloys with Efficient Electromagnetic Wave Absorption

TL;DR

Researchers developed a new material by growing carbon nanotubes on a metal-organic framework-derived alloy, which absorbs electromagnetic waves very efficiently.

Contribution

The study introduces a novel method of in-situ CNT growth on MOF-derived high-entropy alloys for enhanced electromagnetic wave absorption.

Findings

CNTs grown at 800 °C showed a minimum reflection loss of −57.52 dB at 2.3 mm thickness.

The material achieved an effective absorption bandwidth of 4.4 GHz at 1.9 mm thickness.

Abstract

To obtain an excellent electromagnetic wave (EMW) absorption material, a strategy was proposed in this study with the aid of in-situ growth of carbon nanotubes (CNTs) on the surface of a metal–organic framework (MOF)-derived FeCoNiMnMg high-entropy alloy (HEA). The HEA@CNT composite was successfully prepared via a solvothermal method combined with a one-step pyrolysis process. With the pyrolysis temperature increasing from 600 °C to 800 °C, the length of CNTs grew from 200 nm to about 600 nm approximately, while the defect density of CNTs was enhanced. This structural evolution significantly improved the dielectric properties and impedance matching. Consequently, the sample prepared at 800 °C (HEA@CNT-800) exhibited outstanding microwave absorption performances, achieving a minimum reflection loss (RLmin) of −57.52 dB at a matched thickness of 2.3 mm and an effective absorption bandwidth (EAB) of 4.4 GHz at a thinner thickness of 1.9 mm. This work provides a novel perspective for designing high-performance MOF-derived absorption materials.

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