Synthesis of Hierarchical Flower-like MoO2@N-Doped Carbon for Enhanced Microwave Absorption

Abstract Developing efficient microwave absorbers to address severe electromagnetic radiation pollution poses a great challenge. In this work, flower-like MoO2/NC composites were successfully synthesized using a sequential self-assembly strategy. By modulating the reduction temperature, the electromagnetic parameters were optimized, thereby optimizing the dielectric loss. At 700 °C, the resulting MoO2/NC composite exhibited exceptional performance with an RLmin of −64.5 dB (at 1.6 mm) and an EAB covering 4.7 GHz. The superior performance is predominantly ascribed to the unique hierarchical structure formed by self-assembly, facilitating multiple polarization relaxations and multi-interface reflections. Additionally, the successful incorporation of MoO2 nanoparticles reduces the electrical conductivity of the carbon matrix and enhances interfacial polarization, thereby improving impedance matching. Therefore, this study presents a lightweight broadband microwave-absorbing material and offers insights into the design of high-performance microwave absorbers with multicomponent and hierarchical structures.