Hierarchical Porous Carbon Nanotube Skeleton Supported Polydimethylsiloxane Composite with Electrical Continuity for High‐Performance Electromagnetic Shielding

Abstract Electromagnetic (EM) shielding materials have attracted significant attention, owing to their widespread potential in preventing EM irradiation in electrical devices and human bodies. In this study, a hierarchical porous carbon nanotube (CNT) skeleton with electrical continuity is presented, which is rapidly fabricated via the facile microwave pyrolysis of CNT‐coated organic templates, for constructing high‐performance EM shielding materials. Furthermore, the CNT skeleton, which comprises countless intertwined CNTs, can be easily designed into various configurations, such as CNT foams and CNT sheets, with varying conductivities and pore densities. In the as‐constructed CNT‐skeleton‐supported polydimethylsiloxane (PDMS)/CNT‐foam composites, the continuity of intertwined CNTs leads to a high conductivity of 271.2 S m⁻¹ at a CNT loading of 2 wt%. Owing to the multiple reflections and reabsorption of the EM waves in the hierarchical porous CNT skeleton with macroporous, microporous, and hollow structures, the PDMS/CNT‐foam composites exhibit a high EM shielding effectiveness (SE) of 43 dB, mainly via absorption. Additionally, the electrical continuity of the CNT skeleton allows the dissipation of heat in the PDMS/CNT‐skeleton.