Activated carbon fiber/Fe3O4 composite with enhanced electromagnetic wave absorption properties

Abstract

To obtain a low-density material that is capable of absorbing electromagnetic waves over a wide bandwidth, an activated carbon fiber/Fe3O4 composite material (ACF/Fe3O4) was prepared using an in situ reduction method. Scanning electron microscopy images show that Fe3O4 nanoparticles, approximately 10-40 nm in size, were spread uniformly over the surface of the ACF. The resulting composite exhibited superparamagnetic behavior at room temperature. The ability of the ACF and ACF/Fe3O4 composite to absorb electromagnetic waves over a frequency range of 8.2-18 GHz was measured using the arch method. The results showed that the maximum reflectivity of an ACF felt was -12.9 dB at 18 GHz, and the effective microwave-absorbing bandwidth (R < -10 dB) increased to 8.62 GHz (9.38-18 GHz). Coating with nano-Fe3O4 magnetic particles can effectively improve the absorption of electromagnetic waves by the ACF, and this technique therefore has great potential for application to the field of electromagnetic shielding.