A kind of tunable Co/C microwave absorber derived from Co-ZIF-9 for lightweight and efficient microwave absorber

Abstract

Herein, a novel rod-like Co/C composite has been synthesized successfully through an easy approach with a cobaltic metal-organic framework (Co-ZIF-9) as the precursor. After the process of high temperature pyrolysis, porous carbon implanted with governable cobalt nanoparticles was obtained. Due to the Co nanoparticles with the magnetic loss and the porous carbon contributing for the dielectric loss, the combination of the two with the interfacial polarization, the ferromagnetic composites inhibited improved electromagnetic wave absorption. The Co/C composite with 800 °C pyrolysis temperature demonstrated the biggest Co sizes as well as the best electromagnetic absorbing performance among the three samples. The Co/C composite at 800 °C shows thin thickness, lightweight and strong absorption performance, which may be owing to the interactive effects connecting dielectric and magnetic loss. In this work, an optimum value of reflection loss was reached at -44.3 dB with a layer thickness of 2.8 mm and meanwhile with 10 wt.% of the loading content.

Keywords

• ZIF-9
• Co NPs
• Microwave absorber
• Dielectric loss
• Magnetic loss