Hierarchical and Orderly Surface Conductive Networks in Yolk-Shell Fe3 O4 @C@Co/N-Doped C Microspheres for Enhanced Microwave Absorption.

Abstract

Constructing the adjustable surface conductive networks is an innovation that can achieve a balance between enhanced attenuation and impedance mismatch according to the microwave absorption mechanism. However, the traditional design strategies remain significant challenges in terms of rational selection and controlled growth of conductive components. Herein, a hierarchical construction strategy and quantitative construction technique are employed to introduce conductive metal-organic frameworks (MOFs) derivatives in the classic yolk-shell structure composed of electromagnetic components and the cavity for remarkable optimized performance. Specifically, the surface conductive networks obtained by carbonized ZIF-67 quantitative construction, together with the Fe3 O4 magnetic core and dielectric carbon layer linked by the cavity, achieve the cooperative enhancement of impedance matching optimization and synergistic attenuation in the Fe3 O4 @C@Co/N-Doped C (FCCNC) absorber. This interesting design is further verified by experimental results and simulation calculations. The products FCCNC-2 yield a distinguished minimum reflection loss of -66.39dB and an exceptional effective absorption bandwidthof 6.49GHz, indicating that moderate conduction excited via hierarchical and quantitative design can maximize the absorption capability. Furthermore, the proposed versatile methodology of surface assembly paves a new avenue to maximize beneficial conduction effect and manipulate microwave attenuation in MOFs derivatives.