Novel bimetallic MOF derived hierarchical Co@C composites modified with carbon nanotubes and its excellent electromagnetic wave absorption properties

In the severe electromagnetic wave pollution situation, the absorbers must meet the requirements of lightweight, strong absorption, thin thickness and wide band. Under such a circumstance, it is of great significance to construct reasonable structure and composition for excellent electromagnetic wave absorption. Therefore, the Co/C composites anchored with carbon nanotubes (Co@CNTs) have been successfully prepared by rationally regulating the growth of bimetallic MOF and subsequent pyrolysis process. It is revealed that the conduction loss and polarization loss caused by the carbon nanotubes with different lengths and densities and the porosity of the composites are together responsible for the attenuation of electromagnetic wave. As expected, the hierarchical Co@CNTs composites showed a strong reflection loss of -76.6 dB and a broad effective absorption bandwidth of 6.2 GHz through the improvement of impedance matching and electromagnetic wave absorption ability. Herein, this work presents a strategy for the development of composites as promising electromagnetic wave absorbent.