One-dimensional Co/C composite with ultra-wide bandwidth for boosting electromagnetic wave attenuation performance

It remains a challenge to develop electromagnetic wave absorbers with wide effective absorbing bandwidth (EAB). In this work, one-dimensional (1D) cobalt-based metal-organic framework (MOF)-derived composites were exploited on whose surfaces are decorated with nanoparticles. The EAB can reach up to 6.7 GHz with the corresponding matching thickness only 2.2 mm, which is far greater than those of most similar composites. The unique 1D rod microstructures possess a large length-to-diameter ratio and can provide a longer conductive path in a relatively small volume, which can reduce the length of electron transmission paths, and thus improve the overall conductivity. The composites contain a large number of cobalt/carbon heterogeneous interfaces, which can enhance the interface polarization phenomenon. Additionally, the impedance matching can be controlled in balance due to the double-component feature of the composites. The successful preparation of the cobalt-based MOF-derived composites with an ultra-wide EAB can significantly improve the upper limit of EAB of similar composites.