Multi‐Path Electron Transfer in 1D Double‐Shelled Sn@Mo2C/C Tubes with Enhanced Dielectric Loss for Boosting Microwave Absorption Performance

Abstract 1D tubular micro‐nano structural materials have been attracting extensive attention in the microwave absorption (MA) field for their anisotropy feature, outstanding impedance matching, and electromagnetic energy loss capability. Herein, unique double‐shelled Sn@Mo 2 C/C tubes with porous Sn inner layer and 2D Mo 2 C/C outer layer are successfully designed and synthesized via a dual‐template method. The composites possess favorable MA performance with an effective absorption bandwidth of 6.76 GHz and a maximum reflection loss value of −52.1 dB. Specifically, the rational and appropriate construction of Sn@Mo 2 C/C tubes promotes the multi‐path electron transfer in the composites to optimize the dielectric constant and consequently to enhance the capacity of electromagnetic wave energy dissipation. Three mechanisms dominate the MA process: i) the conductive loss resulted from the rapid electron transmission due to the novel 1D hollow coaxial multi‐shelled structure, especially the metallic Sn inner layer; ii) the polarization loss caused by abundant heterogeneous interfaces of Sn‐Mo 2 C/C and Mo 2 CC from the precise double‐shelled structure; iii) the capacitor‐like loss by the potential difference between Mo 2 C/C nanosheets. This work hereby sheds light on the design of the 1D hierarchical structure and lays out a profound insight into the MA mechanism.