Rare earth-induced multiscale dual-phase dielectric hierarchical materials enabled lightweight and broadband electromagnetic response

Abstract

The lightweight, broadband, and electromagnetically responsive materials attract growing attention. The high-value-added utilization of rare earth modification offers a promising approach for this need. However, the uncontrollable generation and inherent homogeneity of rare earths limit the enhancement of electromagnetic wave (EMW) absorption performance. Here, we develop a promising rare earth (La)-induced two-dimensional (2D) MXene-derived multiscale, dual-phase dielectric TiO₂ strategy. This strategy achieves the coupling of zero-dimensional (0D) large-scale anatase (A-TiO₂) and small-scale rutile (R-TiO₂) with one-dimensional (1D) porous nitrogen-doped carbon (PCN) nanofibers (NFs). This strategy effectively modulates the dielectric behavior of MXene/PCN NFs and promotes the formation of 0D/1D/2D multilevel heterogeneous interfaces, achieving lightweight, broadband, and highly efficient EMW absorption properties, with a reflection loss (R_L) value of −61.55 dB and a wide effective absorption bandwidth (EAB) of 5.7 GHz at thin thickness of 1.95 mm. Furthermore, this strategy was achieved through a synergistic electrospinning and thermal treatment process, effectively embedding 0D TiO₂ nanoparticles, La-based species, and 2D MXene nanosheets into 1D PCN NFs. Consequently, favorable interface polarization, conduction loss, and dipole polarization contribute to the outstanding radar stealth properties of the PCN/MXene-La composite. This strategy demonstrates a rare earth-modified approach for interface engineering and morphological engineering of materials, providing a new paradigm for the rational design of rare earth-enhanced electromagnetic behavior.