Catechol grafted rGO/MXene heterosheet structures for high performance electromagnetic interference shielding and thermal management applications

Two-dimensional MXenes have shown extraordinary potential in various scientific areas, including energy harvesting and microwave shielding. Despite their outstanding properties, MXene-based scaffolds suffer from vulnerable mechanical fragility and environmental instability, which reduces the operational life. Here, we used a nature-inspired strong surface adhesion to assemble a stacked heterosheet structure of reduced graphene oxide (rGO) and MXene (Ti3C2TX). Catechol bonding of self-triggered polydopamine between these two-dimensional nanofillers resulted in a dense and well-ordered structure, transforming their mechanical and electrical properties to those of a freestanding sheet. The simultaneous grafting of catechol and the formation of stacked heterosheets with rGO not only protects the MXene sheets from environmental oxidation but also preserves their intrinsic transportation properties. The resulting rGO/MXene composite sheet was ordered and dense, with a tensile strength of 86 MPa and toughness 118.2 MJm−3. The ultrathin, highly flexible, and conductive (26.5 Scm−1) composite sheet exhibited specific shielding effectiveness of 16340, 19136 and 21340 dBcm2g−1 in the X, Ku, and K bands, respectively. Additionally, it showed outstanding Joule-heating properties, with a rapid thermal response of approximately 2 s and the ability to reach a saturation temperature >120 °C at a relatively low supplied voltage of <7 V. The grafted rGO/MXene composite sheet maintained its transportation properties, electromagnetic interference shielding, and electrothermal properties even after 60days of continuous exposure to ambient by suppressing oxidation attacks. The synergistic enhancement of physical properties and environmental stability in the composite sheet suggest a great potential for high-performance, flexible shielding, and thermal management applications in aerospace and automobile electronics.