Chelation-assisted synthesis and magnetic properties of functionalized Graphene-Fe3O4 hybrids

Abstract

Carboxyl-functionalized graphene–Fe₃O₄ hybrids were synthesized via oxidative treatment of graphene nanoplatelets followed by chelation-assisted in situ coprecipitation of magnetite. Spectroscopic and microscopic analyses confirmed the successful introduction of –COOH groups and their role as multidentate ligands, directing the uniform nucleation of nanocrystalline Fe₃O₄ on crumpled graphene sheets. The resulting hierarchical, porous architecture provides intimate interfacial contact between the conductive graphene framework and the magnetic phase, thereby favouring multiple internal reflections, interfacial polarization and synergistic conductive, dipolar and space-charge loss mechanisms. Magnetic measurements demonstrated soft ferrimagnetic behaviour with high saturation magnetization and low coercivity and remanence, a combination desirable for high-frequency absorber applications due to efficient dynamic magnetic loss with limited hysteretic and eddy-current dissipation. These findings establish a clear processing–structure–property relationship and highlight Graphene–COOH/Fe₃O₄ hybrids as promising candidates for lightweight, broadband electromagnetic-absorbing coatings suitable for advanced stealth and electromagnetic protection of high-speed aerial platforms.