Multilevel MoS2/CoNi@helical CNT/N-doped hollow carbon foam for low-loading electromagnetic wave absorption

Lightweight electromagnetic wave absorbing (EMA) materials with low filler loading and environmental adaptability are highly desirable for next-generation electromagnetic protection. Herein, a multilevel MoS 2 /CoNi@helical carbon nanotubes/N-doped hollow carbon foam (MCNC) was constructed for efficient EMA. Helical carbon nanotubes generated under controlled high-temperature conditions introduce chiral and tortuous conductive pathways within the 3D hollow carbon framework, promoting multiple scattering and dielectric loss. The incorporation of MoS 2 interrupts the excessively continuous conductive network, thereby improving impedance matching, while the conductivity and electronic structure differences between MoS 2 and the carbon framework enhance interfacial polarization through charge separation. Benefiting from the synergistic effects of geometric regulation and heterointerface engineering, MCNC achieves a minimum reflection loss of −51.90 dB and a maximum effective absorption bandwidth of 6.32 GHz at an ultralow filler loading of 5 wt%. In addition, MCNC exhibits a surface temperature of 139.0 °C under near-infrared irradiation and excellent corrosion resistance in simulated seawater. This work provides an effective strategy for developing low-loading and multifunctional EMA materials through multilevel structural and interfacial design.