In situ growth of B₄C nanowires on activated carbon felt to improve microwave absorption performance

Boron carbide (B4C) nanowires were synthesized on the surface of activated carbon felt (ACF) via an in situ thermal growth method. The microstructures of B4C nanowires were characterized by field emission scanning electron microscopy, transmission electron microscopy, and x-ray diffraction. The minimum reflection loss (RLmin) value of 40 wt. % ACF@B4C hybrid materials amounts to -36.1 dB at 17.2 GHz and the effective absorption bandwidth (RL < -10 dB) is obtained over a high frequency range of 15.9-18 GHz with an absorber layer thickness of 5 mm. The obtained results prove that ACF@B4C hybrid materials have high potential as microwave absorbers with excellent microwave absorption property.