Synthesis and electromagnetic wave absorption properties of 3D spherical NiCo2S4 composites.

The development of high dielectric loss and magnetic loss for radar absorbing material is a long-term pursuing and under a close scrutiny. Most of the researches have been focused on exploring absorber materials with good absorption performance and at the same time with a good electrical conductivity. To develop a new absorber material will also have significant impacts on boosting the dielectric loss and magnetic loss. Herein, 3D spherical NiCo 2 S 4 (NCS)-based composite has been fabricated via a mild, simple and useful hydrothermal strategy and the electromagnetic wave absorbing properties have been investigated through comparison among NCS, acidified carbon nanotubes (a-CNT)/NCS, reduced graphene oxide (r-GO)/NCS and r-GO/a-CNT/NCS. The experimental results show that the optimal concentration of NiSO 4 ·6H 2 O to synthesize the composites is 6 M. Furthermore, the frequency bandwidth has been broadened and the maximum absorption peaks have been increased after adding the modified agent. The maximum frequency bandwidth of r-GO/a-CNT/NCS is 5.1 GHz below −5 dB and 2.7 GHz below −10 dB respectively, the maximum absorption peak is −35.8 dB at 8.1 GHz. Schematic illustration of the fabrication process for the r-GO/a-CNT/NCS. Image 1 • Different concentration of pure NCS causes various microstructure and properties. • The addition of a-CNT and r-GO can greatly improve the EM absorption properties. • The maximum frequency bandwidth is 5.1 GHz below −5 dB. • The maximum absorption peak is −35.8 dB at 8.1 GHz. [ABSTRACT FROM AUTHOR]