Tunable microwave absorption and shielding effectiveness in the nanocomposite of 3D hierarchical flower-like Co3O4 and rod-like polyindole

Due to the rapid development of wireless electronic devices, achieving an excellent microwave absorber is crucial in modern life. The composite of flower-like Co3O4 and rod-like polyindole (PIn) was embedded in the paraffin matrix for tunable microwave absorption performance and shielding effectiveness. Investigation of microwave absorption features of Co3O4/PIn paraffined composites in the X band frequency range revealed a good performance for 25 wt% Co3O4/PIn paraffined composite with reflection loss and an effective absorption bandwidth of −21.5 dB and 3.5 GHz (covered ∼ 83% X band). The pretty good microwave absorption performance of this composite originated from magnetic loss (by Co3O4), dielectric loss (by PIn), and heat transfer capability (by paraffin). Shielding effectiveness was also increased with the increase of Co3O4/PIn loading percentage, with a total shielding effectiveness of 28.1 dB with the most contribution from shielding effectiveness for absorption. This work provides an easy and low-cost approach for tunable microwave absorption and shielding effectiveness for practical applications.