Synthesis and high frequency structure simulator electromagnetic simulation of hollow NC@CeO2 nanospheres for broad absorption bandwidth

Recent progress in microwave absorption materials stimulate the extensive exploration of rare earth oxide materials. Herein, we report the synthesis of a hollow sphere-based carbon material compounded with rare earth oxides. Hollow N-doped carbon nanospheres loaded ceria composites (H-NC@CeO2) were designed and prepared by the template method, combined with in-situ coating, pyrolysis and chemical etching. By controlling the loading content of H-NC@CeO2 and adjusting the impedance matching of the material, the H-NC@CeO2/PS composite exhibited a minimum reflection loss (RL) of -50.8 dB and an effective absorption bandwidth (EAB) of 4.64 GHz at a filler ratio of 20 wt% and a thickness of 2 mm. In accordance with measured electromagnetic parameters, simulations using the High Frequency Structure Simulator (HFSS) software were conducted to investigate the impact of the honeycomb structure on the electromagnetic wave performance of H-NC@CeO2/PS. By calculating the surface electric field and the material’s bulk loss density, the mechanism of electromagnetic loss for the honeycomb structure was elaborated. A method for structural design and manufacturing of broadband absorbing devices was proposed and a broadband absorber with an EAB of 12 GHz was prepared. This study presents an innovative approach to designing advanced EM wave absorbing materials with broad absorption bandwidths.