Preparation and microwave absorption properties of MWCNTs/RGO/NiFe-LDH three-dimensional composites with varying metal ratios

Abstract

The design of the material structure significantly influences microwave absorption properties. Enhancing electromagnetic performance requires the creation of diverse and heterogeneous interfaces to promote extensive wave reflections. This study developed 3D composites with point (NiFe-LDH), line (multi-walled carbon nanotubes, MWCNTs), and surface (reduced graphene oxide, RGO) architectures using ultrasonic stirring and a hydrothermal process, aiming to achieve improved electromagnetic properties. At a Ni:Fe ratio of 3:1, MWCNTs are interspersed within the layers of reduced RGO, forming a distinctive three-dimensional network structure. Additionally, on the MWCNTs/RGO composite's surface, NiFe-LDH flakes grow uniformly. The resulting composite exhibits an effective absorption bandwidth (EAB) of 5.2 GHz and a minimum reflection loss (RL_min) of −57.93 dB at a thickness of 1.64 mm. Furthermore, a thickness of 1.70 mm achieves a maximum EAB of 6.88 GHz. These results demonstrate that the MWCNTs/RGO/NiFe-LDH composite provides a broad microwave absorption bandwidth and high absorption efficiency, making it a promising candidate for developing advanced materials for microwave absorption applications.