Lightweight MXene Composite Films with Hollow Egg-Box Structures: Enhanced Electromagnetic Shielding Performance Beyond Pure MXene.

MXene is widely used in the electromagnetic interference (EMI) shielding field. However, the high electromagnetic reflectivity of pure MXene causes potential secondary EMI pollution. This study presents a hollow egg-box structure used in MXene composite film, by which the reflectivity (R) could decrease from 0.98 to 0.54 and absorbance (A) increased from 0.02 to 0.45, effectively decreasing the high electromagnetic reflectivity of pure MXene. Additionally, compared to pure MXene films, the MXene composite films exhibit improved electromagnetic interference shielding effectiveness (EMI SE) and SSE/t. The prepared films achieve a peak EMI SE of 69.19 dB at 12.4 GHz, which is 1.3 times higher than pure MXene, and a peak SSE/t of 27 888 dB cm g⁻¹ at 12.4 GHz, 1.4 times that of pure MXene. The hollow egg-box structure not only enhances the electromagnetic shielding performance beyond pure MXene but also demonstrates outstanding performance compared to most reported MXene films, balancing lightweight material properties with effective shielding. Furthermore, the prepared MXene composite films with the hollow egg-box structure show improved water resistance. Therefore, MXene composite films with hollow egg-box structures are promising candidates for advanced EMI devices in future lightweight materials.