Hierarchical Engineering of Double‐Shelled Nanotubes toward Hetero‐Interfaces Induced Polarization and Microscale Magnetic Interaction

Hierarchical engineering of suitable dielectric-magnetic multicomponents shows good performance for microwave absorbers, but still face bottlenecks. Herein, hierarchical double-shelled nanotubes (DSNTs), in which the inner magnetic tubular subunits are assembled by magnetic-heteroatomic components through cation-exchange reactions, and the outer dielectric MnO2 nanosheets strengthen the synergistic interactions between confined heterogeneous interfaces are ingeniously designed and constructed. Hetero-interfaces induced polarization is proposed to investigate the interfacial relaxation mechanism, and magnetic loss, closely related to the micrometer-scale magnetic units, is mainly clarified by the magnetic interaction composed of magnetic coupling and magnetic diffraction; both of them are clearly confirmed by Lorentz off-axis electron holography. The obtained hierarchical DSNTs demonstrate efficient microwave absorption with an optimal reflection loss of -54.7 dB and qualified absorption bandwidth of 9.5 GHz owing to desirable heterogeneous interfaces, multiple magnetic heteroatomic components and hollow hierarchical microstructures. This strategy inspires a generalized methodology for the engineering of hollow hierarchical configurations with multishells, the combination of proposed hetero-interfaces induced polarization and microscale magnetic interaction broadens the dielectric-magnetic synergistic mechanism of the topography-performance relationship for microwave absorption materials.