Light/Heavy Rare Earth‐Doped Mo‐MXene: Excellent Electromagnetic Wave Absorption Based on Dual‐Domain Synergistic Attenuation

Abstract 2D materials such as MXene are prime candidates for next‐generation electromagnetic response materials. However, due to difficulties in atomic level regulation and the inherent drawbacks associated with high conductivity, the production of high‐performance 2D MXene‐based electromagnetic wave (EMW) absorbers remains challenging. In this work, a dual‐element doping strategy is proposed by simultaneously doping a light rare‐earth (RE = La, Pr, Ce) ion and a heavy rare earth (RE = Er) ion. The couple doping realizes a synergistic attenuation in Mo‐MXene, effectively overcoming excessive conductivity. In performance, the light and heavy RE‐doped Mo‐MXene systems enable a universal nature for excellent EMW absorption performance (2 times and 5 times comparing with single element doped and pure Mo‐MXenes). This is because the localized 4f electronic states regulate the dielectric loss. The spin‐orbit coupling effects (so as the electron localization and dipole polarization effects of REs in density functional theory (DFT) calculations) induced by the differences in magnetic moment between heavy and light RE enhance the magnetic loss, which is confirmed by Mo‐MXene/N‐La‐Er, Mo‐MXene/N‐Pr‐Er, and Mo‐MXene/N‐Ce‐Er systems. Furthermore, radar cross‐section (RCS) simulations indicate the potential application of the Mo‐MXene/N‐RE‐Er system in radar stealth. This work presents a practical design strategy for dual‐RE modified high‐performance absorbers.