Synchronously boosting microwave-absorbing and heat-conducting capabilities in CeO 2 /Ce(OH) 3 core-shell nanorods/nanofibers via Fe-doping amount control.

To address the electromagnetic interference (EMI) and heat dissipation issues in electronics, we pioneered the synthesis of Fe-doped CeO 2 /Ce(OH) 3 core-shell nanorods/nanofibers (CSNRs/NFs) through a simple one-pot hydrothermal reaction. The growth of core-shell nanofibers was driven by the minimal surface free energy and vacancy formation energy. By controlling the amount of Fe-doping, not simply Fe 0 content, crystallite size, defects, impurities, and length/diameter ratios could be modulated, but the electric, magnetic, thermal, and microwave absorption performance. The efficient 3D network constructed by 1D nanofibers in a silicone matrix offered a continuous pathway for electrons/phonon relay transmission, endowing the composites with exceptional heating conductance (3.442 W m -1 K -1 ) at 20%Fe-doping. An ultrawide absorption band (9.26 GHz) with intense absorption (-42.33 dB) and small thickness (1.7 mm) was achieved at 10%Fe-doping due to excellent matching performance, strong attenuation ability, and large EM parameters. Overall, Fe-doped CeO 2 /Ce(OH) 3 CSNFs are a promising material for next-generation electronics with effective heat dissipation and EM wave absorption due to their straightforward process, mass production, and outstanding comprehensive performance. Beyond providing a deeper insight into the accurate defect modulation in magnetic-dielectric-double-loss absorbents by doping, this paper proposes an electron/phonon relay transmission strategy to improve heat conductance.