In situ loading of calcium sulfide on N, S Co-doped porous carbon derived from ginkgo biloba leaves to ameliorate the mechanism of electromagnetic wave absorption

Abstract

In response to the diversified needs of wave absorbing materials, multiphase material systems have been the focus of research and have been investigated extensively. However, the role of multiphase and its mechanism of enhancing wave absorption have been little studied. We prepared a new composite system-nitrogen and sulfur co-doped carbon with in situ loaded calcium sulfide, using Ginkgo biloba leaves (GBL)as raw material by a simple and environmentally friendly method. The composite has a three-dimensional porous structure with CaS particles immobilized in the carbon layer. The abundant non-uniform interfaces such as C–CaS, CaS-air and C-air cause interfacial polarization loss. The N and S atoms are doped in such a way that they can elicit dipole polarization. The outcome shows that the material has a minimum RL value of −15.47 dB at 700 °C and an effective absorption bandwidth of 2.08 GHz, achieving a win-win situation in both directions of impedance matching and attenuation capability. Finite element simulations provide strong support for the interpretation of the absorption mechanism. Due to the unique properties and structure of GBL, a new idea is provided for the intelligent design of multi-phase absorbing material systems.