Hierarchical CoFe2O4@PPy hollow nanocubes with enhanced microwave absorption

Ferries are appearing as attractive microwave absorption (MW) materials due to outstanding magnetic properties, simple preparation process, structure stabilization and low price, but poor impedance matching and low conductivity have limited their extensive applications. In this work, hierarchically hollow CoFe2O4/polypyrrole nanocubes (CoFe2O4@PPy HNCs) with enhanced electromagnetic characteristics for MW absorption are fabricated by combining self-sacrificing template and in-situ polymerization route. The CoFe2O4@PPy composites were characterized by XRD, FTIR, XPS, SEM, and TEM. The results verify that PPy are coated equably on the surface of CoFe2O4 nanocubes to form a unique hierarchically hollow structure. Moreover, the electromagnetic characteristics can be adjusted by regulating PPy proportion. The outcomes demonstrate that the as-prepared CoFe2O4@PPy composites has outstanding MW absorbing ability. The desirable microwave absorption is achieved in the composite of CF@PPy-2, where the minimum reflection loss (RL) reaches -43.85 dB at 9.7 GHz with a thickness of 3.0 mm and broad effective bandwidth (RL <= -10 dB) of 5.7 GHz can be achieved at 2.0 mm thickness. This is because the moderate PPy coating endows CoFe2O4@PPy composites with improved impedance matching and multiple loss mechanisms. In view of its excellent MW absorbing performance, hierarchical CoFe2O4@PPy HNCs is expected to be potential MW absorbers for extensive applications.

Automated summary

In this work, hierarchically hollow CoFe2O4/polypyrrole nanocubes with enhanced electromagnetic characteristics for MW absorption were fabricated. The electromagnetic characteristics can be adjusted by regulating the proportion of polypyrrole. The outcomes demonstrate that the as-prepared composites have outstanding MW absorbing ability and are expected to be potential MW absorbers for extensive applications.