Sandwich-like Magnetic Graphene Papers Prepared with MOF-Derived Fe3O4-C for Absorption-Dominated Electromagnetic Interference Shielding

Electromagnetic interference (EMI) shielding materials, entailing the efficient electromagnetic (EM) shielding and high EM wave (EMW) absorption, have become a further requirement for the upcoming 5G communication. Herein, the composite films with a multilayer sandwich structure from cellulose solution in ferric metal- organic frameworks (MOFs) (MIL-88B)-derived magnetic carbon-based materials (C-MIL-88B) and graphene nanoplates (GNPs) are successfully fabricated through a filtration-assisted self-assembly method. The resultant C-MIL-88B/GNP films possess satisfactory saturation magnetization and considerable conductivity with the introduction of Fe3O4-C. Interestingly, the composite film with five layers (0.12 mm) obtains a reliable EMI shielding effectiveness of 28 dB in the X-band frequency range, while the power coefficient of absorption (A) is up to 86%. The improved microwave absorption and attenuation properties of the C-MIL-88B/GNP film are resulted from the synergistic effect of dielectric loss, magnetic loss, and multilayer structure. This work highlights the potential of MOFs/GNP composite films in absorption-dominated EMW protection fields.