Optimization of microwave absorption properties based on the construction of Ni–TiN heterojunctions

In this study, Ni-TiN@CN nanocapsules were successfully prepared by the DC arc method and the self-polymerization reaction of dopamine. The effect of material composition on their microwave absorbing properties was systematically investigated. The crystal structure, core-shell morphology, and the successful construction of the nitrogen-doped carbon layer of samples were confirmed by x-ray diffractometer, Raman spectroscopy, x-ray photoelectron spectroscopy, transmission electron microscopy, and scanning electron microscopy. The synergistic effect of the dielectric and magnetic losses is optimized by the introduction of Ni elements. Electromagnetic parameter tests show that the dielectric relaxation loss of the material is further significantly enhanced by the multi-interface heterostructure constructed after coating the nitrogen-doped carbon shell layer. Ni-TiN@CN nanocapsules have a reflection loss of -47.74 dB at a thickness of 2.6 mm and a combined effective absorption bandwidth (RL < -20 dB) of 4.5 GHz. It exhibits excellent microwave absorption performance. This study provides a new idea for the design of highly efficient microwave absorbing materials. It confirms that the construction of multi-interface heterostructures can effectively regulate the microwave absorbing properties of materials.