Honeycomb-like structured ZnFe2O4@C derived from ZnFe2O4@ZIF-8 for electromagnetic wave absorption

In this paper, ZnFe2O4@Zeolitic imidazolate framework-8 (ZIF-8) composites were prepared by Sol-Gel self -propagating combustion method and in situ growth method. Honeycomb-like structured ZnFe2O4@C composites were obtained using ZnFe2O4@ZIF-8 as the precursor in Ar atmosphere carbonization at 800celcius. The honeycomb -like structure is conducive to enhance the polarization and reflection on the surface of powder particles, which ameliorate the EMW absorption properties of the materials significantly. Wherein, the carbon content can be controlled by ZIF-8 coating. The composite with 5% ZIF-8 (wt%) shows excellent reflection loss value of-36.5 dB at 9.4 GHz with a matching thickness of 2.0 mm, and the corresponding effective absorption bandwidth is 3.5 GHz (7.6-11.1 GHz). The composite with 10% ZIF-8 (wt%) obtain a minimum reflection loss value of-37.8 dB at 10.0 GHz when the thickness is 2.0 mm, and the effective absorption bandwidth is 3.5 GHz (7.9-11.3 GHz).

Automated summary

ZnFe2O4@Zeolitic imidazolate framework-8 (ZIF-8) composites were prepared using Sol-Gel self-propagating combustion method and in situ growth method. The honeycomb-like structured ZnFe2O4@C composites obtained through carbonization at 800°C in Ar atmosphere exhibited enhanced electromagnetic wave absorption properties. The carbon content of the composites could be adjusted by the ZIF-8 coating. The composites with 5% and 10% ZIF-8 (wt%) showed excellent reflection loss values and wide effective absorption bandwidth in the frequency range of 7.6-11.3 GHz.