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

Abstract 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 Fe 15 shelled with organic ligands is employed as a novel magnetic precursor, thus allowing in situ formation and uniform deposition of multicomponent magnetic Fe/Fe 3 O 4 @Fe 3 C and Fe/Fe 3 O 4 nanoparticles on graphene oxides (GOs) and carbon nanotubes (CNTs), respectively. Owing to the good dispersity and efficient magnetic‐dielectric synergy, quaternary Fe/Fe 3 O 4 @Fe 3 C–GO exhibits strong low‐frequency absorption with RL min of −53.5 dB at C‐band and absorption bandwidth covering 3.44 GHz, while ultrahigh RL min of −73.2 dB is achieved at X‐band for ternary Fe/Fe 3 O 4 ‐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 m 2 and 34.37 dB m 2 ). 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.