CoSe2@polythiophene core-shell composites with enhanced interfacial polarization for high-performance broadband electromagnetic absorption

Rational design the composition and structure is an effectual measure to develop the high-performance electromagnetic (EM) wave absorbing materials. In this work, core-shell structured CoSe 2 @polythiophene (CoSe 2 @PTh) composites are synthesized via a simple hydrothermal followed by in-situ polymerization process. Benefiting from the conductive network increased by conductive polymer incorporation, interfacial effects caused by core-shell structure and multi-component optimizing the impedance matching, the EM absorption performance of samples is significantly improved. The minimum reflection loss (RL min ) value of −49.60 dB and the effective absorption bandwidth (EAB) of 4.20 GHz are obtained for CoSe 2 . After cladding, the CoSe 2 @PTh possesses RL min of −55.40 dB and broadened EAB of 5.8 GHz at 10 wt% filling amount. This work broadens the application of transition metal selenide in EM absorption, such as MnSe 2 and NiSe 2 , and provides an eco-friendly and convenient way to construct core-shell structure and multi-component for lightweight broadband EM absorbing materials.