Sandwich CoFe₂O₄/RGO/CoFe₂O₄ Nanostructures for High-Performance Electromagnetic Absorption

The rational design of specific nanostructures with desirable combination of electrical conductivity and magnetism is of significant importance in the field of electromagnetic absorption. To date, it is still difficult to uniformly coat magnetic composition on reduced graphene oxide (RGO) surface, especially through a metal–organic frameworks (MOFs) pyrolyzation strategy, just because of difficulty in even deposition of MOFs on graphene oxide (GO). Herein, we successfully deposit MOFs on GO to form sandwich MOFs/GO/MOFs through the addition of Fe3+ to MOFs precursor. Then, we adopt a temperature-controlled pyrolysis strategy to transform MOFs/GO/MOFs into sandwich CoFe2O4/RGO/CoFe2O4. The nanomaterial exhibits remarkable electromagnetic absorption (EMA) performance, where its maximum effective width reaches 7.08 GHz under 2.6 mm. It is thought that the synergy of electric loss, magnetic loss, and impedance match is ascribed to high-perforamnce EMA of this sandwich nanostructure.