Tunable lateral size and hierarchical structure SiP2@Ni low-dimensional aggregates for enhanced electromagnetic wave absorption

Simplifying the technology for regulating dielectric properties and enriching electromagnetic loss mechanisms of layered electromagnetic wave (EMW) absorption materials still faces challenges. Herein, we propose a simple and eco-friendly sieving strategy to control the lateral size (3–50 μm) of multilayered SiP 2 flakes for regulating dielectric constants. Moreover, hierarchical-structured 2D SiP 2 @0D Ni nanoparticles/1D Ni chains low-dimensional aggregates are in-situ constructed on SiP 2 flakes via a two-step hydrothermal method to enhance interfacial polarization and electromagnetic synergistic effects. When the lateral size was controlled at 11 μm (SiP 2 -300), the intrinsic SiP 2 exhibits strong reflection loss (RL) value of –38.9 dB at 1.7 mm. Notably, the construction of 2D/0D/1D SiP 2 @Ni not only maintains a strong RL of –40.1 dB, but also shifts the corresponding absorption frequency from original Ku-band (11.8 GHz) to C-band (7.2 GHz). More importantly, the effective absorption bandwidth is broadened from 2.9 GHz to 4.1 GHz benefiting from the construction of electromagnetic synergy networks. Additionally, the radar cross section (RCS) value (29.14 dB⸱m 2 ) evaluated by the computer simulation technology (CST) results for SiP 2 @Ni-S2 confirm the excellent dissipation ability. This study provides a new strategy for the application of layered absorbers with low-frequency, broadband and adjustable EMW properties. • Lateral size-sieving strategy simultaneously optimizes the dielectric loss and impedance matching of layered SiP 2 . • Hierarchical SiP 2 @Ni low-dimensional aggregates enable electromagnetic synergy effect for high performance EMW absorption. • Lateral size effect and hierarchical structure enable SiP 2 @Ni-S2 the RL min of –40.1 dB at 7.2 GHz with wide EAB of 4.1 GHz.