Electron Migratory Polarization of Interfacial Electric Fields Facilitates Efficient Microwave Absorption

Abstract

High-performance microwave absorption materials (MAM) are often accompanied by synergistic effects of multiple loss mechanisms, but the contribution share of various loss mechanisms has been neglected to provide a template and reference for the design of MAM. Here, a highly conductive 2D structure is designed through a functional group-induced structure modulation strategy, composite L-Ni@C can reach an effective absorption bandwidth of 6.45 GHz at 15% fill rate, with a maximum absorption efficiency of 99.9999%. Through the layer-by-layer analysis of the loss mechanism, it is found that the strong loss originates from the polarization loss at the heterogeneous interface. The movement of space charge between the two-phase interface forms an interfacial electric field, and the in situ doping of nitrogen is cleverly achieved by the introduction of amino functional groups, which significantly enhances the rate of space charge transfer between the two-phase interface and greatly facilitates the electron migration polarization. The space charge motion law of the interfacial electric field is also simulated using COMSOL simulation software to illustrate the electron migration polarization mechanism at heterogeneous interfaces. This work fills the gap of functional group-induced structural modulation and presents new theories into the mechanism of space charge movement at heterogeneous interfaces.