In-situ synthesis of multi-principal-element (Mo0.25Cr0.25Ti0.25V0.25)3C2Tx MXene-based composites with enhanced electromagnetic wave absorption

Nowadays, the increasingly severe electromagnetic (EM) wave pollution requires high-performance EM wave absorbing materials. Multi-principal-element materials are acknowledged as promising for broadening the applications owing to their tunable chemistries and structures in many fields, including as EM wave absorbers. Herein, we prepared a high-entropy MXene, (Mo0.25Cr0.25Ti0.25V0.25)3C2Tx. Furthermore, multi-principal -element (Mo0.25Cr0.25Ti0.25V0.25)3C2Tx/FeCoNi and (Mo0.25Cr0.25Ti0.25V0.25)3C2Tx/FeCoNiCu composites were synthesized via an in-situ hydrothermal process by combining high-entropy MXene with medium-entropy magnetic alloys. In contrast with the relatively narrow effective absorption bandwidth (EAB) of (Mo0.25Cr0.25-Ti0.25V0.25)3C2Tx MXene (2.56 GHz), (Mo0.25Cr0.25Ti0.25V0.25)3C2Tx/FeCoNi composite with 50 wt% MXene can attain an optimum EAB of 4.88 GHz with the matching thickness of only 1.73 mm. As for (Mo0.25Cr0.25-Ti0.25V0.25)3C2Tx/FeCoNiCu composites, both the absorption efficiency and absorption bandwidth are significantly enhanced. The combination of multi-principal-component strategy and composite construction endows the composites with synergistic dielectric and magnetic losses, optimized impedance matching as well as enhanced attenuation ability, thus improving EM wave absorption performances. In addition, radar cross section (RCS) simulation confirms that the prepared composites have broad application prospects as radar stealth materials.