Synthesis of ZSM-5/FexOy@C/Ni microspheres for enhanced electromagnetic wave absorption

Reasonable microstructure design and composition of absorbing materials are essential to improve absorbing properties. In this paper, ZSM-5/FexOy@C/Ni composite absorbing material with double core-shell structure was prepared by hydrothermal method and sol-gel method. The composite's structure, morphology, chemical composition, and magnetic properties were studied. The surface and C layer of ZSM-5 were densely covered with FexOy and Ni nanoparticles, respectively. At the same time, the uniform distribution of magnetic units can effectively improve the spatial distribution of magnetism. It was worth noting that the optimized composites had excellent microwave absorption properties. When the sample thickness was 2.5 mm, the minimum reflection loss of the sample could reach -21.4 dB, and the maximum effective bandwidth could reach 5.4 GHz. It was found that by changing the carbon layer's thickness, the prepared sample's absorption property could be adjusted to achieve the best impedance matching. The superior electromagnetic absorption performance of ZSM-5/FexOy@C/Ni composite microspheres was due to the synergistic effect of dielectric loss and magnetic loss and the enhanced porous core-shell interface effect. These results indicated that the composite could be used as a promising new type of high-performance absorbing material.