关键词: La₂O₃@Ti₃C₂T_x, 反射损耗, 频率选择表面, 极化损耗

Abstract:

MXene possesses high dielectric loss and a distinctive layered structure, yet its single-component characteristic gives rise to intense electromagnetic wave reflection, which severely restricts its microwave absorption efficiency. In this study, La₂O₃@Ti₃C₂T_x nanocomposites were fabricated by immobilizing La₂O₃ nanoparticles onto exfoliated Ti₃C₂T_x nanosheets via amino-bond linkage, with temperature adopted as a pivotal parameter to modulate the absorption performance. Ti₃C₂T_x was derived from the Ti₃AlC₂ precursor through LiF-assisted wet etching, ultrasonication and centrifugation. The phase composition and microstructure of the composites were characterized by XRD, SEM and TEM, while their electromagnetic parameters in the X-band were measured using a vector network analyzer. The optimal absorption performance was attained at a temperature of 60 ℃. At a thickness of 3.8 mm, the minimum reflection loss reaches −50.5 dB at 9.2 GHz, and the effective absorption bandwidth fully covers the X-band (8.2–12.4 GHz). Furthermore, the microwave absorption performance is further optimized by simulating the loaded frequency selective surface, with the reflection loss in the X-band all below −10 dB at a thickness of 3.2 mm. Mechanistic analysis based on electromagnetic field simulation confirms that the exceptional absorption behavior originates from LC resonance. This work provides a novel and feasible strategy for designing and fabricating high-performance Ti₃C₂T_x-based microwave absorbing materials, which shows promising application prospects in the field of electromagnetic protection.

Key words: La₂O₃@Ti₃C₂T_x, Reflection loss, Frequency selective surface, Polarization loss