Hierarchical 3D Bilayer Magnetic Foam/MXene Film Composites for High‐Performance Absorption‐Driven Electromagnetic Interference Shielding

Polymer composites exhibiting absorption‐dominated electromagnetic interference (EMI) shielding with minimal reflection are highly attractive for advanced electronic systems due to their ability to minimize secondary electromagnetic radiation pollution. However, achieving high EMI shielding that is primarily governed by microwave absorption‐dominated attenuation remains a significant technical hurdle. In this work, we developed a bilayer foam/film structure consisting of porous magnetic graphene nanoplatelet (GnP)@zinc ferrite (ZnFe 2 O 4 )/polydimethylsiloxane (PDMS) foam and conductive MXene/PDMS film. This is assembled through a combined method using a simple and cost‐effective sugar‐template approach, along with a layer‐on‐layer casting strategy. The bilayer configuration enables the porous GnP@ZnFe 2 O 4 /PDMS foam to function as an effective microwave absorption layer, while the MXene/PDMS film acts as a robust reflection layer. This integrated bilayer structural synergy promotes a multiple scattering and successive absorption–reflection–reabsorption process, resulting in an outstanding absorption coefficient of 0.79 and a remarkable EMI shielding effectiveness of 82.65 dB. This study demonstrates the effectiveness of combining magnetic foams with conductive films to achieve highly efficient EMI shielding materials with prominent direction‐dependent absorption features.