Efficient Electromagnetic Wave Absorption of Porous CoO–Co@RGO Composites with Optimized Impedance Matching Derived from Metal-Organic Frameworks

In this study, we have successfully synthesized porous CoO–Co@RGO composites using GO and Co-based metal-organic frameworks (MOFs) as precursors. Due to particular structures and advantageous characteristics, the synthesized porous CoO–Co@RGO composites exhibit outstanding electromagnetic (EM) wave absorbing properties with a filler loading of 10 wt.% in wax matrix. The maximum reflection loss (RL) of the prepared porous CoO–Co@RGO was − 3 4 . 2 2 dB with 2.1 mm thickness, and the effective absorption bandwidth as wide as 6.24 GHz (11.76–18 GHz), which covers the full Ku-band. Remarkably, the achieved all values of RL were under − 1 0 dB with 1.0–5.0 mm thickness, the corresponding to bandwidth range can be tuned to 13.84 GHz (4.16–18 GHz). The superior absorbing performance is attributed to suitable magnetic loss, high dielectric loss and large attenuation mainly caused by conduction loss and polarization relaxation.