One-step synthesis of chestnut-like magnetic CNOs@PANI with microwedge enhanced electromagnetic wave absorption

Abstract

In this study, a novel chestnut-like structured magnetic carbon nano-onion (MCNOs)@polyaniline (PANI) core-shell material was synthesized through a one-step in situ oxidation polymerization method under ice-bath conditions. The morphology of the chestnut-like shell was influenced by the type of protonic acid and the polymerization temperature with sulfuric acid at 0-5 °C. The MCNOs@PANI composite material demonstrated improved electromagnetic wave (EMW) absorption performance, with a minimum reflection loss (RL) of −47.82 dB at 14.64 GHz and a maximum electromagnetic wave absorption bandwidth (EAB) of 4.40 GHz at a thickness of 1.5 mm. The superior EMW absorption performance was attributed to the unique chestnut-like surface structure, enhanced core-shell impedance matching, and synergistic effects of the MCNOs and PANI. The study provides a creative approach for advancing the development of carbon-based EMW absorbers with enhanced absorption capabilities.