Impedance matching optimization of hierarchical carbon fiber@MoS2@PANI nanocomposite with core‐sheath structure for achieving excellent microwave absorption

Abstract Carbon fiber (CF) has been extensively used in the research of microwave absorption owning to its excellent performance, but it also faces a series of problems such as impedance mismatch and low absorption intensity. The core‐sheath microstructure with CF as the inner core is constructed to solve the above issues by the introduction of other sheath layers. In this work, the MoS 2 sheath and polyaniline (PANI) sheath are successively introduced into the CF matrix to obtain a hierarchical CF@MoS 2 @PANI nanocomposite with core‐sheath structure through a straightforward hydrothermal method and in‐situ polymerization. The obtained CF@MoS 2 @PANI nanocomposite exhibit the minimum reflection loss value of −42.23 dB at 10.11 GHz while the thickness is 2.5 mm, much higher than those of pure CF (below −10 dB) and CF@MoS 2 nanocomposite (−25.60 dB). Moreover, the distinctive hierarchical core‐sheath structure contributes to providing more active sites, prolonging the transmission path of electromagnetic waves, and forming heterogeneous interfaces. Consequently, the electromagnetic wave attenuation mechanism of CF@MoS 2 @PANI nanocomposite is attributed to a synergistic effect of conductive loss, multiple reflection/scattering, dipole polarization, and interface polarization. This work offers an effective and promising strategy to design a three‐dimensional hierarchical core‐sheath microstructure for the development of composite absorbers.