Fabrication of hollow core-shell NiCo₂O₄@polypyrrole nanofibers/reduced graphene oxide ternary composites with excellent microwave absorption performances

In contemporary times, electromagnetic radiation poses a significant threat to both human health and the normal functioning of electronic devices. Developing composites as adsorption materials possess exceptional electromagnetic wave absorption performances can efficient address this critical issue. Herein, hollow core-shell NiCo2O4@polypyrrole nanofibers/reduced graphene oxide (NiCo-HFPR) composites are fabricated by the combination of electrostatic spinning, air calcination, in-situ polymerization, freeze-drying and hydrazine vapor reduction. As anticipated, NiCo-HFPR-0.2 exhibits noteworthy properties, with the minimum reflection loss (RLmin) of -61.20 dB at 14.26 GHz and 1.56 mm, as well as the effective absorption bandwidth (EAB) of 4.90 GHz at 1.57 mm. Additionally, the simulation procedure is employed to determine the radar cross-section (RCS) attenuation. In comparison to a singular perfect electrically conductive (PEC) layer, the PEC layer coated with NiCo-HFPR-0.2 consistently yields an RCS value below -10 dB m(2) within the range of -60 degrees < theta < 60 degrees. The RCS attenuation value of the NiCo-HFPR-0.2 coating achieves an outstanding 31.0 dB m(2) at theta = 0 degrees, strongly affirming the ability to effectively attenuate electromagnetic wave in real-world applications. The employed experimental methodology, the meticulously crafted composite, and the simulation outcomes presented in this study bear great promise for the progressive advancement of both theoretical investigations and practical applications within the domain of electromagnetic wave absorption.