Regulating microstructure and composition by carbonizing in-situ grown metal-organic frameworks on cotton fabrics for boosting electromagnetic wave absorption

High-temperature carbonized metal-organic frameworks (MOFs) derivatives have demonstrated their superiority for promising electromagnetic wave (EMW) absorbers, but they still suffer from limited EMW absorption capacity and narrow bandwidth. Considering the advantage of microstructure and chemical composition regulation for the design of EMW absorber, hierarchical heterostructured MoS₂/CoS₂-Co₃O₄@cabonized cotton fabric (CF) (MCC@CCF) is prepared by growing ZIF-67 MOFs onto CF surface, chemical etching, and carbonization. Aside from the dual loss mechanism of magnetic-dielectric multicomponent carbonized MOFs, chemical etching and carbonization process can effectively introduce abundant micro-gap structure that can result in better impedance matching and stronger absorption capacity via internal reflection, doped heteroatoms (Mo, N, S) to supply additional dipolar polarization loss, and numerous heterointerfaces among MoS₂, CoS₂, Co₃O₄, and CCF that produce promoted conduction loss and interfacial polarization loss. Thus, a minimal reflection loss of −52.87 dB and a broadest effective absorption bandwidth of 6.88 GHz were achieved via tunning the sample thickness and filler loading, showing excellent EMW absorption performances. This research is of great value for guiding the research on MOFs derivatives based EMW absorbing materials.