Controllable Preparation of Helical Carbon Nanofibers for Electromagnetic Wave Absorption

Helical carbon nanofibers (HCNFs) with enhanced wave-absorbing properties are successfully prepared by a combustion method catalyzed by Sn-MOF and with an appropriate amount of water as the combustion additive. A series of characterization methods, such as X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and transmission electron microscopy, consistently show that microstructures suitable for microwave absorption and scattering are formed in the prepared HCNFs with a relatively uniform size. The microwave absorption properties of these HCNFs are investigated in detail in this study. The HCNF-0.25, HCNF-0.5, and HCNF-0.75 samples showed much better microwave absorbing capacity compared with the HCNF-0 sample under the filling ratio of 20 wt %. The HCNF-0.75 sample exhibited a minimum reflection of −54.445 dB at 2.4 mm. Overall, this work provides valuable insights for more in-depth exporting of dielectric loss to enhance the microwave absorption properties of the nanomaterials.