Hierarchical fiber composites assembled from MOF-derived hollow polyhedral for electromagnetic wave absorption

The appropriate component design and structure regulation are efficient strategies for the generation of high-efficiency electromagnetic wave absorbers, especially for problems such as the single loss mechanism and insufficient impedance matching of transition metal sulfides in electromagnetic wave absorption. Based on this, a hierarchical 0D@1D@2D fiber composite was fabricated, inspired by the "snowflake" in nature. The hierarchical fiber structure integrated with multiple heterogeneous interfaces satisfies the synergistic interaction between different components, and superior EMW absorption performance is attained. The minimum reflection loss (RL_min) of the VCCC fiber composites is −43.76 dB, and the effective absorption bandwidth (EAB) is up to 6.56 GHz. Owing to the presence of multiple non-homogeneous interfaces, the 0D@1D@2D hierarchical VS₂@Co@CNTs@NCNFs (VCCC) fiber composites exhibit intense interfacial polarization, while defects in the samples emerge as polarization centers, producing dipole polarization. Synergistic effects of electrostatic spinning-derived 1D carbon nanofiber “stems”, VS₂-derived 2D nanosheets “petals”, and 0D metal Co nanoparticles “stamens”. The excellent structural design endows the VCCC fiber composites with favorable conductive loss and polarization loss, while the magnetic Co nanoparticles endow the materials with intense magnetic loss, enabling the VCCC fiber composites to exhibit favorable electromagnetic wave absorption properties. Finally, this work provides a powerful reference for the development of EMW absorbing materials based on transition metal sulfides.