Mxene/GOP-Fe3O4 Reinforced Poly(vinyl alcohol) Hydrogels with Broadband Electromagnetic Interference Shielding in X-Band and Extremely Low Frequencies.

Electromagnetic interference (EMI) pollution has emerged as a critical challenge alongside rapid advancements in modern electronics. Here, we report the design and synthesis of multifunctional poly(vinyl alcohol) (PVA) hydrogels reinforced with MXene/GOP-Fe3O4 composites via a facile one-pot hydrothermal strategy. The unique combination of two-dimensional conductive fillers and magnetic Fe3O4 nanoparticles endows the composite hydrogels with enhanced electrical conductivity, magnetic responsiveness, and structural flexibility. MXene and GOP synergistically construct continuous conductive networks, while the in situ-generated Fe3O4 nanoparticles effectively improve low-frequency electromagnetic wave attenuation through magnetic loss. The optimized hydrogel achieves an average specific shielding effectiveness (SSE) of 158.69 dB cm-1 in the 8.2-12.4 GHz range, coupled with excellent broadband absorption and low density. Besides, the shielding tube made from composite hydrogel also has 10.5 dB shielding effectiveness at 10 kHz. Additionally, the composite exhibits pronounced photothermal conversion capability, reaching 48.5 °C under xenon lamp irradiation. These results demonstrate that integrating conductive and magnetic components within a flexible hydrogel matrix offers a versatile pathway for developing lightweight, broadband EMI shielding materials with additional multifunctionality for future wearable and miniaturized electronic systems.