3D lightweight CoFe2O4/graphene aerogel nanocomposites for efficient electromagnetic wave absorption

The rapid advancement of 5G technology and wearable electronics has intensified the demand for high-performance electromagnetic wave absorption (EA) materials. Developing lightweight, efficient, and broadband EA materials is essential to mitigate electromagnetic pollution. In this work, CoFe 2 O 4 /graphene aerogel (GA) nanocomposites were fabricated via a simple hydrothermal and freeze-drying method. The effect of CoFe 2 O 4 nanoparticles on the microstructure and EA properties was systematically investigated in detail. Results indicated that the nanocomposites with 4.5 wt% CoFe 2 O 4 (CFO 4.5 /GA) exhibited the optimal performance, achieving a minimum reflection loss (RL min ) of -42.99 dB and an effective absorption bandwidth (EAB) of 3.68 GHz at a thickness of 4.0 mm. Notably, the RL min of CFO 4.5 /GA is six times higher than that of GA. Radar cross-section (RCS) simulations further confirm its superior EA capability, with a maximum RCS reduction of 40 dB·m 2 at θ = 25°. The impedance matching was optimized by adjusting the complex permittivity of GA and permeability of CoFe 2 O 4 , avoiding reflection. Subsequently, the penetrated waves are attenuated and converted into thermal energy during propagation. Due to its excellent thermal conductivity of GA and the effective combination of CoFe 2 O 4 and GA, the heat generated from magnetic and dielectric losses can be efficiently transferred and dissipated. Owing to its lightweight structure and outstanding EA performance, the CFO 4.5 /GA nanocomposites possess significant promise for shielding high-power wearable electronic devices from electromagnetic interference.