Intelligent diffusion regulation induced in-situ growth of cobalt nanoclusters on carbon nanotubes for excellent electromagnetic wave absorption

Abstract

To achieve strong electromagnetic wave absorption performance at thin thicknesses, a chemical vapor deposition approach was employed to prepare Co nanoclusters modified carbon nanotubes. The main mechanism lies in the formation of dispersed oxides on the basis of low melting point and decomposition temperature of cobalt nitrate hexahydrate, while solid oxides are not easy to agglomerate during reduction due to their poor diffusion properties. Additionally, the abundant nitrogen-doped on carbon nanotubes provides abundant metal deposition sites, which further inhibits metal agglomeration. As expected, the reflection loss was robust at −59.96 dB with a low filler loading of 10 wt%, and the bandwidth was broad at 5.4GHz. Several factors contribute to excellent electromagnetic wave absorption, such as multiple reflections and scattering in the internal space, dipole polarization loss induced by plenty of functional groups, and interfacial polarization loss at the interfaces between Co nanoclusters and carbon nanotubes.