A lightweight and efficient hollow sunken carbon@MnO2/reduced graphene oxide composite for high-performance electromagnetic wave absorption

Abstract

To address the environmental and health issues stemming from electromagnetic pollution, it is crucial to investigate high-performance and practical materials for absorbing electromagnetic waves. Herein, the ternary lightweight SC@MnO2/RGO (SCMR) composites are synthesized by using a special kind of hollow sunken carbon nanoparticles (SC) as a substrate and combining MnO2 nanosheets with 2D reduced graphene oxide (RGO). The investigation results show that the minimum reflection loss (RLmin) of SCMR3 can reach −60.95 dB with a matched thickness of 1.47 mm and a frequency of 13.12 GHz, and the effective absorption bandwidth (EAB) is 4.08 GHz (13.76–17.84 GHz) at the thickness of 1.23 mm. Its excellent performance comes from high dielectric loss capability, multiple reflections, interfacial polarization, and defective polarization relaxation brought by the structure of the composite, which can effectively enable electromagnetic wave absorption and facilitates energy conversion. Furthermore, simulation-based assessment under far-field conditions elucidates the radar stealth effect, demonstrating that the maximum radar cross-section (RCS) attenuation value of SCMR3-coated perfect electrical conductor (PEC) at Phi = 0° and θ = 0° can attain 32.13 dB m2. Ultimately, this study presents a viable design methodology for developing lightweight, efficient, and application-oriented carbon-based electromagnetic wave absorption materials.