Design of hierarchical 1D–2D NiCo 2 O 4 as high-performance microwave absorber with strong loss and wide absorbing frequency

Nowadays, the studying of high-performance microwave absorber with the features of broad bandwidth and strong absorption to address the electromagnetic wave pollution is still a challenge. Thus, based on the careful design of structure and composition, a novel high-performance microwave absorber of hierarchical 1D–2D NiCo 2 O 4 integrating one-dimension nanofibers and two-dimension microsheets is prepared via facile hydrothermal method and subsequent annealing process. The formed NiCo 2 O 4 can be well adjusted under the different annealing temperature. Particularly, varying the annealing temperature from 280 to 600 °C regulates the composition and physicochemical property, further optimizing the microwave absorption performance of hierarchical 1D–2D NiCo 2 O 4 . Therefore, when the annealing temperature is 320 °C and the fill ratio in the paraffin is 30%, maximum reflection loss and efficient frequency bandwidth below − 10 dB are − 41.8 dB and 5.35 GHz at a thickness of 2 mm respectively. The superior absorption performance is due to conductive loss, dipole polarization loss, multiple scattering and multiple reflection, which illustrates that hierarchical 1D–2D NiCo 2 O 4 could be regarded as a strong-loss, broadband, and lightweight microwave absorber.