Carbon nanotubes modified CoZn/C composites with rambutan-like applied to electromagnetic wave absorption

Abstract

The preparation of magnetic metal/carbon composites by pyrolysis of metal organic framework (MOFs) have great potential in lightweight electromagnetic (EM) wave absorption. Nevertheless, it is of great significance to design the three-dimensional (3D) hierarchical structure with synergistic effect from unique MOFs for enhancing the EM wave absorption performance. More importantly, through pyrolysis of MOF, the uniform distribution of magnetic metal and carbon material can be controlled. Herein, Co/Zn-MOF-11 microspheres are used as a precursor pyrolyzed in argon atmosphere to prepare 3D hierarchical rambutan-like bimetallic/carbon@carbon nanotubes (RBC@CNTs) composites. The RBC@CNTs composite pyrolyzed at 800 °C exhibits excellent EM wave absorption performance due to the unique structure and multiple loss mechanisms. A maximum reflection loss of −49.8 dB at 13.6 GHz can be achieved when the filler loading of 3D hierarchical RBC@CNTs composite is 20 wt% with the thickness of 2.4 mm. In addition, the effective absorption bandwidth achieves 5.5 GHz (RL ≤ −10 dB). This strategy to synthesis a unique hierarchical structure is instrumental in enhancing the attenuation of EM wave.