Core-shell heterostructured nanofibers consisting of Fe7S8 nanoparticles embedded into S-doped carbon nanoshells for superior electromagnetic wave absorption

Electromagnetic wave absorption has been of great significance with the imminent era dominated by high-tech electronic products. Engineering microstructural configurations with microwave responding components are believed to be an effective approach in optimizing the electromagnetic wave absorbing performance. Herein, we developed a core-shell fibrous nanocomposite via cellulose-assisted ferric deposition, followed by in-situ wrapping with sulfur-containing polymer. After one-step carbonization, a ternary core-shell heterostructure was formed, in which the Fe7S8 nanoparticles were embedded in-between the S-doped carbon (SdC) nanoshells and carbonized bacterial cellulose (CBC) nanofibers. The resultant SdC@Fe/CBC composites can dramatically dissipate the incident electromagnetic wave through multiple-interfacial polarization and sulfur dipolar polarization. Additionally, the extensive magnetic domains exposed from the nano-sized Fe7S8 further consume electromagnetic energy by magnetic resonance. Consequently, the SdC@Fe/CBC composites exhibit minimum reflection loss of -64.1 dB and a broadband effective absorption (8.5 GHz) with a low filler loading at 5.0 wt% only.

Automated summary

In this study, a core-shell fibrous nanocomposite was developed using cellulose-assisted ferric deposition and in-situ wrapping, which can dissipate electromagnetic waves through multiple-interfacial polarization and sulfur dipolar polarization. Additionally, the nano-sized Fe7S8 particles exposed extensive magnetic domains for magnetic resonance to further consume electromagnetic energy. The resulting composites exhibited low reflection loss and broad effective absorption frequency range.