Temperature controlled yolk-shell-like VO2(M)/Ti3C2Tx composite films for high-performance electromagnetic interference shielding

With the rapid development of communication technology, it will lead to many electromagnetic wave (EMW) pollutions affecting the normal operation of precision instruments in industry. Then need smart electromagnetic interference (EMI) shielding material to protect the instrument from electromagnetic radiation. In this paper, multi-dimensional architectures yolk-shell-like VO2(M)/Ti3C2Tx MXene (MXene) composite films (VM) were successfully prepared by hydrothermal treatment and electrostatic self-assembly. Yolk-shell-like VO2(M) microspheres were riveted onto few-layer MXene nanosheets as a smart EMI shielding material. Above 65 °C, the metal-insulator phase transition (MIT) of VO2(M) changes from the semiconductor state to the metallic state. VM composite films possess temperature controlled EMI shielding properties, which have not been reported before. When the thickness is 29.06 µm, the composite sample exhibits an EMI SE of 43.5 dB at 85 °C, which is 8 dB higher than room temperature. Besides, the few-layer structure and the unique yolk-shell-like structure of VM composite films exhibit excellent dielectric loss. The introduction of few-layer MXene nanosheets improves the EMI shielding performance of yolk-shell-like VO2(M) microspheres and achieves optimized impedance matching. Therefore, VM composite films are expected to provide new ideas for smart EMI shielding materials.