MOF-Derived Yolk-Shell NiCo/ZnO/C Composites with Efficient Microwave Absorption Properties

Well-organized metal-organic framework (MOF)-derived carbon-based materials exhibit ideal electromagnetic (EM) absorption performance. Nevertheless, it is still a challenge to reduce the complex permittivity and obtain high electromagnetism compatibility. Herein, magnetic rod-like carbon composite NiCo/ZnO/C with a metal-semiconductor interface structure was successfully fabricated through the pyrolysis of Ni/Co/ZiF8 MOF precursors. By comparing the EM wave properties of three materials, NiCo/ZnO/C displayed the optimal performance by virtue of the cooperation of complex permittivity dielectric loss and the magnetic loss of the composite. ZnO optimized the EM performance of NiCo/ZnO/C with a minimum reflection loss (RL) value (-50.7 dB) at 9.1 GHz and thickness of 2 mm. It is demonstrated that ZnO particles dispersed uniformly in the outer layer, which became a "green channel" to enhance the maximum intake of electron transport. Furthermore, the synergy between ZnO and NiCo generated an effective impedance match, enabling EM waves to easily enter the interior of the composite. The aim of this paper is to design and construct a platform containing dual-metals and oxide carbon-based composites for an efficient EM wave absorber. It has been proved that coating oxide on metallic carbon-based materials is an effective way to synthesize microwave absorbers with enormous potential. [GRAPHICS] .