Rational construction of heterogeneous interfaces for bimetallic MOFs-derived/rGO composites towards optimizing the electromagnetic wave absorption

Abstract

Rational construction of heterogeneous interfaces is an effective strategy to explore high-performance electromagnetic waves (EMWs) absorption materials. Herein, we adopt a facile solvothermal and pyrolysis process to fabricate the multicomponent and multidimensional composites containing the bimetallic FeNi or FeCo@N-doped graphene layer core–shell heterojunctions/N-doped carbon nanorods/reduced graphene oxide (FeNi@NC/NCR/rGO or FeCo@NC/NCR/rGO) derived from NH2-bimetallic (FeNi or FeCo)-metal organic frameworks (MOFs)/GO precursors. The excellent EMWs absorption performances are effectively achieved and regulated via the content of rGO and the filler loading. Compared with the case without rGO, the FeNi@NC/NCR/rGO composite (25 wt% filler loading) displays a strong reflection loss (RL) of −52.61 dB at 14.44 GHz with a thin thickness of 1.65 mm, and effective absorption bandwidth (EAB) is 4.64 GHz. And the FeCo@NC/NCR/rGO composite (20 wt% filler loading) displays a strong RL of −59.42 dB at 17.8 GHz with a thinner thickness of 1.42 mm, and EAB is 5.28 GHz at 1.66 mm. Their excellent absorption properties result from the synergistic effect between the increased dielectric loss (interfacial polarization, dipole polarization and conduction loss), impedance matching and attenuation constant. These results provide a pathway to prepare the multicomponent and multidimensional composites with superior EMWs absorption.