NiCo₂O₄ nanosheets decorated on one-dimensional ZnFe₂O₄@SiO₂@C nanochains with high-performance microwave absorption

One-dimensional (1D) ZnFe₂O₄@SiO₂ (ZS) nanochains were prepared with Stöber method under external magnetic field. Then, 1D ZS nanochains were covered with a uniform polydopamine (PDA) shell, and the pyrolysis process was completed to obtain 1D ZnFe₂O₄@SiO₂@C (ZSC) nanochains. Finally, 1D flower-like ZnFe₂O₄@SiO₂@C@NiCo₂O₄ (ZSCNC) nanochains were fabricated through a simple hydrothermal method. The carbon layer with strong dielectric loss enabled the 1D ZSC nanochains to achieve an ultra-wide effective absorption bandwidth (EAB) of 6.22 GHz. Compared with the above nanochains, the 1D ZSCNC nanochains showed more excellent microwave absorption (MA) properties because of the unique 1D flower-like architectures having large surfaces and multiple interfaces. The sample loaded with 30 wt% 1D flower-like ZSCNC nanochains showed strong MA performances with a minimum reflection loss (RL) value of -54.29 dB (11.14 GHz) and an EAB of 5.66 GHz (11.94-17.60 GHz) at the thickness of 2.39 mm. The 1D flower-like ZSCNC nanochains with strong absorption, broad absorption bandwidth (almost the entire Ku band) and thin layer has a good application prospect for the absorption of electromagnetic waves in Ku band.