Defect-rich heterostructures Co-MoS2-xOx@NC fibers derived from in-situ grown metal-organic frameworks towards high electromagnetic wave absorption

Defect-rich heterointerfaces integrated with adjustable crystalline phases and atom vacancies as a promising strategy to boost electromagnetic wave (EMW) absorption. However, challenges remain in precisely controlling the balance between construction and the electromagnetic loss mechanism. In this study, an innovative Co-MoS2-xOx@NC core-shell fiber with multiple loss mechanisms was synthesized through an in-situ growth and carbonization process. This structure ingeniously combines ZIF-67 with a carbon fiber (CNF) conductive network to form continuous conductive pathways, providing an ideal medium for conduction loss. Simultaneously, Co ions embedded between MoS2 layers induce strong lattice distortion and abundant vacancies, forming numerous heterointerfaces between Co, MoS2, and CNF. Significant differences in electron density and charge redistribution at the interface greatly enhance interfacial polarization loss. MoS2 stacked nanosheets extend the transmission path of EMWs, dissipating electromagnetic energy by enhancing multiple reflections and scattering. Consequently, Co-MoS2-xOx@NC fibers achieve a strong EMW with a minimum reflection loss of −66.43 dB at 1.98 mm and a wide effective absorption bandwidth of 5.80 GHz at 1.87 mm. This study highlights synergistic effects of lattice vacancies and heterogeneous interfaces, offering a promising solution for constructing an advanced CNF matrix wave-absorbing material.