Regulation mechanism for the formation and microwave absorbing performance of CNT/CoFe-MOF derived hierarchical composite

ABSTRACT The structure design, performance analysis, and process optimization of CNT/MOF-derived hierarchical composite play an important role in the development of high-performance microwave absorbing materials. Herein, the preparation, morphology evolution, and electromagnetic wave absorption mechanism of CNT/MOF-derived hierarchical composite were systematically investigated. The regulation mechanism was revealed by studying the changes in the morphological characteristics, electromagnetic properties, and microwave absorbing performance of CNT/MOF-derived hierarchical composite under different process parameters. The results show that the morphological characteristics and interface bonding between CNT and MOF have a great impact on the absorptive capacity. The composite with composition of 0.28Co/0.26Fe has a maximum absorption of −46 dB at 8.6 GHz and a thickness of 4 mm. In addition, the absorption band with reflection loss values of less than −20 dB can be operated with this thickness between 7.15 and 10.18 GHz, showing excellent absorbing ability and electromagnetic wave bandwidth. The regulation mechanism of CNT/MOF-derived hierarchical composite mainly depends on the effect of Lorentz force, the ion disorder of CoO-Fe2O3 heterojunction, and the spin polarization mechanism of free electrons. This study further improves the corresponding theoretical basis and new design principles, which provides technical support for the development of high-performance absorbing materials. Graphical abstarct