Surface plasmon resonance-enhanced dielectric polarization endows coral-like Co@CoO nanostructures with good electromagnetic wave absorption performance

Geometry and microstructure are two of the most significant factors associated with the electromagnetic wave absorption performance. Here, novel coral-like Co@CoO nanostructures assembled by Co@CoO core–shell nanofibers are synthesized via versatile hydrothermal and reduction treatment processes. The as-prepared Co@CoO nanostructure has vast surface area, abundant interface and numerous dipoles, which generate empowered interfacial and dipole polarizations. Compared to the traditional cobalt absorbers, this new coral-like Co@CoO nanostructure give rise to strong surface plasmon resonance (SPR), resulting enhanced local electric field and further boosting the dielectric polarization in a great extent. The SPR-enhanced dielectric polarization endows coral-like Co@CoO with good electromagnetic wave absorption performance. Coral-like Co@CoO-550 with 25 wt% loading exhibit dual-peak electromagnetic reflection loss at −20.6 dB and −62.76 dB and effective absorption bandwidth at 3.60 GHz with a thickness of 1.65 mm.