Enhanced X-band microwave shielding via Fe3O4 nanoparticle-decorated few layered nitrogen-doped reduced graphene oxides: Synthesis, characterization, and performance assessment

Abstract

Currently, developing lightweight with good microwave (MW) shielding efficacy materials are exceedingly challenging. The challenging task for a few layers of nitrogen-doped reduced graphene oxide (FLN-rGO) derived from thermal N-deposition with an exfoliation under the pyrolysis process. Concurrently, nitrogen-doped heteroatoms FLN-rGO structure possessing an additional electron can enhance the electrical conductivity and function as an electroactive site that enhances MW shielding effectiveness (SE). Besides, the synthesized Fe₃O₄-FLN-rGO NCs are self-sustaining, lightweight, and have strong chemical stability and outstanding MA performance due to the presence of chemical interaction between each other and the development of hierarchical structure formation. The structural and chemical interaction properties of pristine and Fe₃O₄-FLN-rGO composites are investigated using high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS). These analyses confirmed that Fe₃O₄ NPs are homogeneously decorated on the FLN-rGO surface and revealed the chemical interactions between Fe₃O₄ and N-rGO, as evidenced by the Fe–O–C bonding signal observed in the Fe₃O₄-N-rGO (1:2) composites. The Fe₃O₄ NPs demonstrated remarkable saturation magnetization (M_s) and low coercivity (H_c), indicating that quantum confinement effects moderate their soft ferromagnetic characteristics. With a lightweight shielding materials thickness of 0.5 mm, these composites demonstrated an outstanding average MW SE of 44.73 dB at 8 GHz and a superb MW attenuation value (α = 845.05), indicating their excellent efficacy as materials for advanced MW shielding applications.