Multifunctional MXene/holey graphene films for electromagnetic interference shielding, Joule heating, and photothermal conversion

In wearable and microelectronic devices, there is a rising need for ultrathin electromagnetic interference (EMI) shielding films with multifunction, such as Joule heating and photothermal conversion. MXene has shown promising applications in EMI shielding due to its excellent electrical conductivity, abundant surface functional groups, and layered structures. However, the self-stacking, poor mechanical strength and hydrophilicity of MXene hinder its applications. In this study, MXene/holey graphene (MX/HG) composite film is fabricated in a layered structure. The hydrogen bonds between HG and MXene improve the mechanical properties and prevent the self-stacking of MXene sheets. EMI shielding performances are investigated according to the monolayer MXene sheets' size and HG's mass ratio. As a result, the large lamella-based MX/HG composite film shows outstanding EMI shielding effectiveness (EMI SE) of 56.15 dB, excellent low-voltage-driven Joule heating (up to 100 °C at 3 V within 4 s), and high-efficiency photothermal conversion (up to 49.8 °C under 1000 W m⁻² within 30 s) at a thickness of 5 μm. The multifunctional film achieves impressive EMI shielding, Joule heating, and photothermal conversion performances at a low thickness, showing great prospects in wearable and microelectronic device applications.