Achieving the interfacial polarization on C/FeC heterojunction structures for highly efficient lightweight microwave absorption.

Design of dielectric/magnetic heterostructure and multiple interfaces is a challenge for the microwave absorption. Thus, in this study, a novel C/FeC nanocomposites have been fabricated by annealing the precursors obtained by the facile chemical blowing of polyvinyl pyrrolidone (PVP) and Fe(NO)·9HO. By changing the content of Fe(NO)·9HO, the honeycomb-like structure with scads of pores and electromagnetic parameters could be successfully tailored. When the addition of Fe(NO)·9HO is ranging from 1 to 2g, honeycomb-structured nanocomposites possess high performance microwave absorption when mixed with 90wt% paraffin. The minimal reflection loss is -37.4dB at 13.6GHz and effective bandwidth can reach to 5.6GHz when the thickness is 2.0mm, indicating its great potential in microwave absorbing field. Its outstanding microwave performance is tightly related to the porous structure and substantial interface such as carbon/air and carbon/FeC, which are in favor of the impedance matching and interfacial polarization. Thus, our study may provide a good reference for the facile synthesis of light-weight carbon-based nanocomposites with effective interfacial polarization.