Integrating Hierarchical Interfacial Polarization in Yeast-Derived Mo2C/C Nanoflower/microsphere Nanoarchitecture for Boosting Microwave Absorption Performance

Integration of hierarchical polarizations within one nanoarchitecture combines superiorities of strong dielectric polarization loss and matched characteristic impedance for enhancing microwave absorption (MA) performance. However, accurate regulation of polarization relaxations in hierarchical composites remains a considerable challenge. Herein, novel Mo2C@N, P dual-doped carbon microspheres with excellent MA performance have been prepared via a facile yeast-template method. The collaborative composite consists of a hierarchically porous carbon substrate, the embedded ultrafine Mo2C nano particles, and the decorated Mo2C/C nanoflowers. Their maximum reflection loss value reaches as much as -50.6 dB and the effective absorption bandwidth is up to 5.4 GHz with a thickness of 2.5 mm, which are superior to those of most carbonaceous absorbents reported previously. These excellent data mainly result from the following three mechanisms. First, multiple heterointerfaces among the air, carbon matrix, and Mo2C nanoparticles contribute to the strong dielectric polarization loss capacity. Second, the doping of heteroatoms doped can trigger intensive dipole polarization. Third, porous structure induces strong space charge polarization and multiple scattering of electromagnetic waves. These achievements provide a biotemplate method for the general preparation of porous metals or metal compounds/carbon composites with broad application prospects in the MA field. (C) 2022 Elsevier Ltd. All rights reserved.