The new insight into the microscopic enhancement mechanism of microwave absorption based on the electromagnetic heterogeneous interface of carbon nanocavity

Qingsong Li; Yong Zeng; Meixi Zhang; Zhiyuan Jiang; Zhaoxiong Xie

doi:10.1016/j.jcis.2025.138210

The new insight into the microscopic enhancement mechanism of microwave absorption based on the electromagnetic heterogeneous interface of carbon nanocavity

J Colloid Interface Sci. 2025 Jun 19;699(Pt 2):138210. doi: 10.1016/j.jcis.2025.138210. Online ahead of print.

Authors

Qingsong Li¹, Yong Zeng¹, Meixi Zhang¹, Zhiyuan Jiang², Zhaoxiong Xie¹

Affiliations

¹ State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.
² State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China. Electronic address: zyjiang@xmu.edu.cn.

PMID: 40578081
DOI: 10.1016/j.jcis.2025.138210

Abstract

Reasonable microstructure design is an effective strategy to obtain high-efficiency microwave absorbers. The current explanation for the mechanism of microwave absorption enhancement by microstructures is limited to impedance matching and attenuation constant variation, which lacks a more intuitive understanding. To investigate the microwave absorption enhancement mechanisms arising from hollow structural features and heterointerfaces, a N-doped carbon framework with hollow cavities (H-NC) and embedded iron nanoparticles (H-NC/Fe) was strategically designed and synthesized. Notably, the optimized H-NC/Fe-2 composite demonstrates an extended effective absorption bandwidth (EAB) of 7.1 GHz (10.9-18.0 GHz). Experimental results and numerical simulations demonstrate that the enhancement of the effective medium and the establishment of the inhomogeneous interface caused by the cavity structure promote electron migration. The heterogeneous interface caused by magnetic particle loading effectively regulates the electron transport efficiency in the composite material, and changes the induced electric field strength and displacement current density in the composite material. This study integrates numerical simulations with experimental validation, establishing a coherent physical model that bridges critical theoretical gaps in conventional electromagnetic composites, and put new insight into the impact of micro-cavity structure and heterogeneous interface on the microwave response mechanism.

Keywords: Displacement current; Electric field mode; Interface polarization; Microwave loss mechanism; Nano-cavity structure; Numerical simulation; Tip effect.