Mesoporous Heterostructure Sio2@Sic@C Composites with Maze Effect for Enhanced Electromagnetic Wave Absorption

Abstract

Clever microstructure design and multi-component nanocomposite have been proven to be effective strategies for preparing superior electromagnetic wave (EMW) absorbers. Rational component modulation is also a necessary route to realize high-performance EMW absorption. Herein, we successfully fabricated mesoporous heterogeneous SiO2@SiC@C microspheres via a self-assembly technology using mesoporous SiO2 as the precursor. The dielectric properties and impedance matching of SiO2@SiC@C composites have been successfully changed by adjusting the composition of the composites, which exhibit excellent microwave absorption properties. Among them, SiO2@SiC@C-2 shows excellent EMW absorption performance. The minimum reflection loss (RL) can reach -64.2 dB at 15.7 GHz at 2.0 mm and wave absorption bandwidth (EAB) can achieve 6.0 GHz (12 GHz-18 GHz) covering the whole Ku band. This excellent performance is attributed to the intense interfacial polarization induced by the abundance of heterogeneous interfaces among the different phases. At the same time, The SiO2 phase and the hierarchical structure of the porous can modulate the complex dielectric constant, resulting in better impedance matching. This research offers a creative thought for exploring stronger absorption of EMW absorbers.

Keywords: Electromagnetic wave absorption, mesoporous heterogeneous SiO2@SiC@C microspheres, Interfacial polarization, Heterogeneous interfaces