Cross‐Scale Regulation of MOF‐Derived Gradient Heterointerfaces for Microwave Absorption

ABSTRACT Metal–organic frameworks (MOFs) derivatives are preferred choices for developing superior microwave absorbers due to their manipulatable compositions and porous architectures. However, traditional optimization strategies often focus solely on regulating morphology and composition, overlooking their highly flexible cross‐scale designability. Moreover, the microwave response mechanisms of heterointerfaces at different scales remain unclear. To address this limitation, we achieved differentiation in microwave response through an exterior‐to‐interior cross‐scale heterointerfaces design. External large‐scale regulation first optimized impedance matching, followed by internal small‐scale regulation that strengthened the attenuation characteristics. Via a two‐step approach, controllable coating of carbon nanotubes was first achieved at the sub‐micrometer scale. Subsequently, in situ selenization was performed at the nanoscale, constructing high‐density multiphase heterointerfaces. This design inherits the compositional advantages of MOF derivatives, critically, decouples the regulation scales. Benefiting from this cross‐scale design, the prepared sample achieved a superior electromagnetic response, achieving remarkable loss of −66.86 dB and broadband EAB of 5.99 GHz at 1.73 mm matching thickness. This study elucidates the synergistic effect of large‐scale impedance optimization and small‐scale loss enhancement driven by the cross‐scale regulation of heterointerfaces, offering a route for the development of advanced absorbers through the full utilization of MOF derivatives.