Porous magnetic carbon CoFe alloys@ZnO@C composites based on Zn/Co-based bimetallic MOF with efficient electromagnetic wave absorption.

To obtain lightweight and efficient electromagnetic wave absorbing materials, Fe2O3@ZnCo-MOF composites were prepared in this paper by in-situ growth method, and CoFe alloys@ZnO@C composites were obtained by subsequent annealing process. By varying the loading of Fe2O3 during the synthesis process, a series of composites were obtained. Among them, CoFe alloys@ZnO@C-0.1 has the best electromagnetic wave absorption performance, which can reach a reflection loss (RL) of -40.63 dB at a thickness of 2.2 mm, while the reflection loss is -44.13 dB at a thickness of 5.0 mm, and the maximum effective absorption bandwidth (EAB) is 5.84 GHz at a thickness of 2.4 mm. The excellent performance can be attributed to the synergistic effect of the dielectric and magnetic properties of the composites as well as the effective impedance matching properties. Thus, the CoFe alloys@ZnO@C composite is expected to be a lightweight and efficient material for electromagnetic wave absorption.