Preparation and microwave absorption properties of the hollow ZnFe2O4@C composites with core-shell structure

The hollow ZnFe2O4@C composites with core-shell structure were successfully synthesized through a simple method. SEM and TEM results illustrate that the hollow ZnFe2O4@C composites are of core-shell structure with an average diameter of about 200 nm. Compare with hollow ZnFe2O4, the as-prepared hollow ZnFe2O4@C composites exhibit excellent microwave absorption properties in terms of the minimum reflection loss, the thickness and the absorption bandwidth. The minimum reflection loss of hollow ZnFe2O4@C composites is −51.38 dB at 15.39 GHz with the thickness of 2.0 mm and the absorption bandwidth below −10 dB is up to 4.10 GHz (12.56–16.66 GHz) with the thickness of 2.2 mm. These excellent absorbing properties are result to the multi-component synergistic effect and its unique structure.