Design and fabrication of a hollow nanobowl-like heterostructured PPy@Co/CoFe2O4@HNBC composite as a remarkable electromagnetic wave absorber

Abstract

A heterostructured polypyrrole@magnetic Co/CoFe2O4 nanoparticles@hollow nanobowl-like carbon (PPy@Co/CoFe2O4@HNBC) composite with a layer-by-layer (LBL) structure based on HNBC was prepared via a facile three-step process. HNBC was synthesized by a typical template method, then sequentially decorated with Co/CoFe2O4 and PPy via in-situ growth and polymerization. The relationship between the structure, components, and electromagnetic wave (EMW) absorption performance of PPy@Co/CoFe2O4@HNBC was studied in depth. The EMW absorbing research shows that PPy@Co/CoFe2O4@HNBC exhibits excellent EMW absorption capability, with a minimum reflection loss (RLmin) of up to −61.85 dB at 12.80 GHz and 1.90 mm and a widest effective absorption bandwidth (WEAB, RL≤−10.00 dB) value of 5.60 GHz at 1.70 mm. The excellent EMW absorption performance of PPy@Co/CoFe2O4@HNBC can be ascribed to the multiple reflection and scattering that occurs due to its unique microstructure and the synergistic effects between the polarization and conduction induced dielectric loss, and the natural resonance and exchange resonance induced magnetic loss. As a consequence, the PPy@Co/CoFe2O4@HNBC composite designed in this work is a hopeful candidate for application in the field of EMW absorption.