Bidirectional Mo4/3CT x MXene/Graphene Aerogels for Tailored Microwave Absorption

• Published in: ACS applied nano materials 2025-01, Vol.8 (4), p.1978-1990
• Main Authors: Shamshirgar, Ali Saffar, Qin, Leiqiang, Rojas-Hernández, Rocío E., Halim, Joseph, Fernandez, Jose F., Hussainova, Irina, Rosen, Johanna
• Format: Article
• Language: English
• ISSN: 2574-0970; 2574-0970
• DOI: 10.1021/acsanm.4c06555

Microwave absorbing materials (MAMs) play critical roles in electromagnetic interference (EMI) shielding, stealth technology, and wireless communication systems. This study introduces a bidirectionally grown hybrid aerogel microwave absorber comprising Mo4/3CT x MXene, graphene-augmented inorganic nanofibers (GAIN), and poly­(vinyl alcohol) (PVA). The resulting aerogel demonstrates anisotropic properties and exceptional microwave absorption efficiency relative to its weight and thickness with dielectric relaxation serving as the primary loss mechanism. The research highlights the fabrication process of the hybrid aerogel and explores the underlying absorption mechanisms, emphasizing dipolar interactions and polarization mechanisms. Experimental and theoretical results reveal that the interaction of Mo4/3CT x MXene and graphene-augmented inorganic nanofibers within the PVA matrix significantly enhances microwave absorption in the GHz range through a multitude of dielectric polarization relaxation mechanisms and architectural features working synergistically. Notably, an aerogel with a thickness of 2.1 mm with only 5 vol % Mo4/3CT x achieved an outstanding effective absorption bandwidth of 4.2 GHz and a minimum reflection loss of −37 dB. The anisotropic nature of the structure plays a pivotal role in its absorption capabilities, while the chemical interactions between the inclusions and the PVA matrix amplify the dominance of polarization relaxation as the primary loss mechanism. This study demonstrates how careful architectural design and precise material selection can produce a lightweight, high-performance absorber with minimal MXene content, leveraging its low dimensionality and chemical versatility to maximize efficiency while highlighting the potential of Mo4/3CT x MXene for microwave absorption in electronic and telecommunication systems.