1D CNTs assembled MOF-derived hollow CoSe2@N-doped carbon constructed high-efficiency electromagnetic wave absorbers

Abstract

Optimizing impedance matching is crucial to achieve high-efficiency electromagnetic wave (EMW) absorption performance. In this work, Hollow CoSe2@N-doped Carbon/Carbon Nanotube-x (HCSC/CNTs-x) with unique three-dimensional conduction network was synthesized by using protection etching and high-temperature selenization strategies. The conductivity of HCSC/CNTs-x was regulated by varying the content of CNTs, and the extended three-dimensional electron transport pathway resulted in enhanced conduction and multiple reflection loss, while also optimizing impedance matching. Hollow CoSe2@N-doped carbon (HCSC) further facilitates the optimization of impedance matching. The abundant heterogeneous interfaces and defects induce strong interface polarization and dipole polarization, and the multiple loss mechanisms work in concert to confer excellent EMW absorption performance to HCSC/CNTs-x. The RLmin of HCSC/CNTs-30 reaches −41.68 dB, and the EABmax is 4.92 GHz at only 2.0 mm. The design strategy of three-dimensional conduction network of HCSC/CNTs-x provides an effective way to achieve the impedance matching optimization of CoSe2-based EMW absorption materials.