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

Abstract

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[Formula: see text]wt.% in wax matrix. The maximum reflection loss (RL) of the prepared porous CoO–Co@RGO was [Formula: see text][Formula: see text]dB with 2.1[Formula: see text]mm thickness, and the effective absorption bandwidth as wide as 6.24[Formula: see text]GHz (11.76–18[Formula: see text]GHz), which covers the full Ku-band. Remarkably, the achieved all values of[Formula: see text]RL were under [Formula: see text][Formula: see text]dB with 1.0–5.0[Formula: see text]mm thickness, the corresponding to bandwidth range can be tuned to 13.84[Formula: see text]GHz (4.16–18[Formula: see text]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.