Abstract: MXene has recently emerged as a promising candidate for advanced electromagnetic functional materials. However, the disadvantages of poor oxidation stability, insufficient mechanical strength and incompatible multiple functions of MXene seriously impede its practical applications. To this end, we herein propose a novel tannic acid (TA) dual-modification strategy to fabricate TA-ANF/TA-MXene (AT/MT) composite films via vacuum-assisted filtration and hot-pressing techniques. TA enables the aramid nanofibers (ANF) to form hydrogen/coordination bonds with MXene, therefore enhancing interfacial adhesion with expanded MXene interlayers. It not only facilitates the formation of continuous and intact conductive network within the film, but also enhances the attenuation of electromagnetic waves at the TA-ANF/TA-MXene interface, thereby boosting the electromagnetic interference (EMI) shielding effectiveness. As such, the optimized AT/MT-10 film exhibits an X-band EMI shielding effectiveness of 33.92 dB, tensile strength of 148.56 MPa, and low infrared emissivity (0.27, rising to only 0.29 after 72 h hygrothermal aging at 95% RH/50 °C). It also integrates efficient Joule heating (92.3 °C at 5 V) and photothermal conversion (69.2 °C under 1 sun). These findings lay solid foundations for preparing multifunctional materials with synergistic infrared stealth, electromagnetic protection, as well as photothermal performance.

Key words: MXene, Electromagnetic shielding, Composite films, Tannic acid treatment, Photothermal performance