Broadband electromagnetic dissipation superiority of hierarchical ZnO flakes co-decorated with CoFe/CoFe₂O₄ and rGO

Currently, in order to solve the increasing issues caused by the electromagnetic radiation pollution and broadened radar detection bandwidth, electromagnetic wave dissipating materials with high performance of broadband absorption are desired urgently. Herein, the CoFe/CoFe₂O₄/ZnO/rGO composites composed of hierarchical ZnO flakes with anchored CoFe/CoFe₂O₄ and rGO-doping were synthesized via a facile aging approach and subsequent calcination process under vacuum atmosphere. The constituents and electromagnetic parameters of absorbers could be efficiently modulated through tuning the additive amount of raw GO. Notably, the composite with GO additive amount of 0.025 g exhibits a prominent broadband electromagnetic wave absorbing capacity. In detail, the widest effective absorption bandwidth reaches 7.66 GHz with thin thickness of just 2.5 mm. This superior broadband microwave absorption property is owing to the synergistic effect of hierarchical nanostructure and well-matched impedance, as well as enhanced interfacial polarization, conduction loss, eddy current, natural and exchange magnetic resonances. The investigation demonstrates the specific CoFe/CoFe₂O₄/ZnO/rGO composite is a potential candidate to be applied for broadband military radar stealth and serious electromagnetic radiation contamination.