Two‐step preparation of fly ash‐based composites for microwave absorption

Abstract

Accompanying with the rapid development of electronic components and devices, the abundant electromagnetic interference and radiation have caused serious influences on electric communication and human health. [1][2][3] Thus, it is urgent to design an excellent MA material with the performances of strong absorption, broad frequency range, tiny thickness, and low cost for solving electromagnetic pollution. As is known, an ideal absorber is a hybrid material composed of both magnetic loss and dielectric loss. 4,5 Recently, considerable efforts have been devoted to combining magnetic components with carbon materials to fabricate hybrid composites, 6-8 which not only can regulate impedance matching, but also improve the attenuation ability. However, it remains a great challenge to prepare these carbon-based materials using a simple and lowcost method.FA, the solid waste, is generated during the combustion of coal in coal-fired power plants. Its improper disposal has become a serious environment problem. 9 Due to the chemical composition and unique morphology of FA, its application fields have already involved in the synthesis of zeolite, backfill material, lightweight aggregate, road subbase, building materials, agricultural melioration, element extraction, sewage disposal, and so on. 10 Furthermore, although the FA cenosphere has the potential for fabricating excellent microwave