A simple strategy to develop heterostructured carbon paper/Co nanoparticles composites with lightweight, tunable and broadband microwave absorption

Constructing the multicomponent composites with more tunable structure parameters is conducive to optimize the electromagnetic (EM) properties, which is an effective way to develop high-efficient microwave absorbers (MAs). Herein, heterostructured lightweight carbon paper (CP)/Co nanoparticles composites were elaborately designed and produced through a simple high temperature annealing process. By controlling the annealed temperature, the as-prepared CP/Co heterostructures with different contents of CP could be obtained, which resulted in the tunable EM and EM wave absorption properties (EMWAPs). The obtained results revealed that the enhanced content of CP effectively boosted their conduction loss and polarization loss abilities. And the as-prepared CP/Co heterostructures displayed the outstanding comprehensive EMWAPs including strong absorption capability, broad frequency bandwidth and thin matching thickness. Furthermore, the EMWAPs of obtained CP/Co samples could be further improved by optimizing the concentration of Co sources. Especially, the as-prepared CP/Co3-750 sample displayed a minimum reflection loss value of −70.23 dB with a matching thickness (dm) value of 2.26 mm, and an effective absorption bandwidth of 4.80 GHz with the dm value of 1.74 mm, respectively. Therefore, our findings not only presented a simple and viable route to produce magnetic CP-based heterostructures, but also provided an effective strategy to develop the lightweight, tunable and broadband high-efficiency MAs.