The rapid transition from 5G to 6G wireless technologies has led to a substantial increase in electromagnetic interference (EMI), posing significant challenges to device reliability, signal integrity, and human health. There is an urgent need for lightweight, flexible, and efficient absorption-dominant EMI shielding materials. In this study, we propose a rationally designed coaxial electrospinning strategy to fabricate hierarchical MXene/reduced graphene oxide/polyacrylonitrile core–shell nanofibers. This design integrates a conductive, MXene-rich core surrounded by a reduced graphene oxide/polyacrylonitrile outer shell, encouraging simultaneous optimization of electrical conductivity, impedance matching, and polarization loss to achieve superior EMI shielding performance and thermal blocking. Interestingly, when the reduced graphene oxide to MXene ratio was optimized to be 1:2, the resultant composite nanofiber revealed an EMI shielding effectiveness of 74.38 dB at X-band, a shielding efficiency of 99.99999635%, a high electrical conductivity (169.81 S·cm–1), and an outstanding specific shielding effectiveness of 2.54 × 104 dB·cm2·g–1. Additionally, the sample exhibited effective thermal insulation, with the surface temperature rising by only 41 °C after 1 min of exposure to a 75 °C heat source. These findings highlight the synergy between the high electrical conductivity of MXene, which enables strong internal reflection and ohmic loss, and the interfacial polarization of reduced graphene oxide, which fosters multiple internal reflections that enhance absorption. This optimized, absorption-dominated mechanism provides valuable guidance for designing next-generation lightweight and flexible EMI shielding materials for applications in aerospace, 5G/6G communications, and advanced electronic devices.
Kassa et al. (Mon,) studied this question.