RGO supported bimetallic MOFs-derived Co/MnO/porous carbon composite toward broadband electromagnetic wave absorption

Abstract

The metal-organic frameworks-derived carbon-based electromagnetic wave (EMW) absorbing (EMWA) materials have attracted extensive attention. However, it still maintains a challenge to design the kind of materials with wide effective absorption bandwidth (EAB). Herein, a series of reduced graphene oxide (RGO) supported symmetrical lotus-like cobalt/manganese oxide/porous carbon (Co/MnO/PC/RGO) composites were synthesized by hydrothermal method and subsequent carbonization process. Impressively, the symmetrical porous structure and the special component could synergistically improve EMWA capacity. On the one hand, the symmetrical porous structure and magnetic component could optimize impedance matching, which were conducive to more EMW entering into the sample. On the other hand, the abundant heterointerfaces enhanced the interface polarization and the EMWA performance of the sample could be also regulated by the change of GO content in the mixture. When the GO content was 9 wt%, a minimum reflection loss value of −50.1 dB and the corresponding EAB value of 5.1 GHz (11.9–17.0 GHz) was achieved at a thickness of 2.0 mm. The excellent EMW performance of the sample stemmed from the increased dielectric loss and magnetic loss as well as improved impedance matching. As a consequence, this work authenticated a novel pathway to construct the carbon-based EMW absorbers with broad EAB.