Dual-Interfacial Polarization Enhancement to Design Tunable Microwave Absorption Nanofibers of SiC@C@PPy

To improve the microwave absorption (MA) performance of SiC nanofibers, dual interfaces were designed on the surfaces of SiC nanofibers to form SiC@C@PPy heterostructures. The inner carbon and outer polypyrrole (PPy) layers were synthesized through gas etching and oxidative polymerization, respectively. Benefitting from polarization enhancement in dual interfaces and the well-established conductive networks in the composite, SiC@C@PPy nanofiber-loaded composites reveal ideal electromagnetic attenuation and impedance matching properties. The best effective absorption bandwidth (EAB) of SiC@C@PPy nanofibers can reach 8.4 GHz at a thickness of 2.78 mm with a filler loading of 15 wt %. Moreover, by modulating the thickness of the samples, the EAB can cover the whole X (8–12 GHz) and Ku (12–18 GHz) bands.