Embedding Multiple Magnetic Components in Carbon Nanostructures via Metal-Oxo Cluster Precursor for High-Efficiency Low-/Middle-Frequency Electromagnetic Wave Absorption

With the advent of wireless technology, magnetic-carbon composites with strong electromagnetic wave (EMW) absorption capability in low-/middle-frequency range are highly desirable. However, it remains challenging for rational construction of such absorbers bearing multiple magnetic components that show uniform distribution and favorable magnetic loss. Herein, a facile metal-oxo cluster (MOC) precursor strategy is presented to produce high-efficiency magnetic carbon composites. Nanosized MOC Fe15 shelled with organic ligands is employed as a novel magnetic precursor, thus allowing in situ formation and uniform deposition of multicomponent magnetic Fe/Fe3O4@Fe3C and Fe/Fe3O4 nanoparticles on graphene oxides (GOs) and carbon nanotubes (CNTs), respectively. Owing to the good dispersity and efficient magnetic-dielectric synergy, quaternary Fe/Fe3O4@Fe3C-GO exhibits strong low-frequency absorption with RLmin of -53.5 dB at C-band and absorption bandwidth covering 3.44 GHz, while ultrahigh RLmin of -73.2 dB is achieved at X-band for ternary Fe/Fe3O4-CNT. The high performance for quaternary and ternary composites is further supported by the optimal specific EMW absorption performance (-15.7 dB mm-1 and -31.8 dB mm-1) and radar cross-section reduction (21.72 dB m2 and 34.37 dB m2). This work provides a new avenue for developing lightweight low-/middle-frequency EMW absorbers, and will inspire the investigation of more advanced EMW absorbers with multiple magnetic components and regulated microstructures. Metal-oxo cluster precursor strategy is proposed to construct magnetic-carbon composites with well-dispersed multiphase magnetic nanoparticles. Iron-oxo cluster Fe15 is selected as novel precursor and the derived Fe/Fe3O4@Fe3C-graphene oxide (GO) and Fe/Fe3O4-carbon nanotubes (CNT) exhibit high-efficiency microwave absorption at low-/middle-frequency due to dielectric-magnetic synergy arisen from multicomponent magnets and abundant heterointerfaces. This work opens up a novel method for designing low-/middle-frequency absorbers with high performance.image

Automated summary

A metal-oxo cluster precursor strategy is proposed to construct magnetic-carbon composites with well-dispersed multiphase magnetic nanoparticles. The Fe/Fe3O4@Fe3C-graphene oxide (GO) and Fe/Fe3O4-carbon nanotubes (CNT) derived from this strategy exhibit high-efficiency microwave absorption at low-/middle-frequency due to the dielectric-magnetic synergy arising from multicomponent magnets and abundant heterointerfaces. This work opens up a novel method for designing high-performance low-/middle-frequency absorbers.