Fabrication of MWCNTs/rGO/PPy ternary composites for excellent electromagnetic absorption

With the development of radar stealth technology and electronic communication technology, electromagnetic (EM) wave absorbing materials with lightweight and broad absorbing bandwidth are widely expected. In this study, the multi-walled carbon nanotubes (MWCNTs)/reduced graphene oxide (rGO)/polypyrrole (PPy) ternary composites were prepared by in-situ polymerization under hydrothermal conditions. The effects of carbon substrate of MWCNTs/rGO and the content of PPy on the microwave absorption (MWA) properties of the ternary composites and the corresponding attenuation mechanism were investigated. The results showed that MWCNTs and rGO nanosheets interweave together to form a relatively uniform micro-network structure with even wrapping of PPy on the surface of MWCNTs/rGO substrate. The adjustable amount of PPy optimizes the impedance matching and EM wave attenuation capacity. The composites achieve effective absorption bandwidth (EAB) of 4.6 GHz at 2.1 mm, and the minimum reflection loss (RL_min) value of −57 dB at 15.8 GHz. The multi-void network structures formed by MWCNTs and lamellar rGO and the interfacial polarization between MWCNTs/rGO composite carbon substrate and PPy can effectively decay EM wave absorption, thus improving the MWA performance of the composites. This work provides an effective reference for the application of multi-component carbon composites in the field of microwave absorption.