A lightweight MXene-Coated nonwoven fabric with excellent flame Retardancy, EMI Shielding, and Electrothermal/Photothermal conversion for wearable heater

Multifunctional wearable heater has attracted great interest in personal thermal management, but its potential safety hazards triggered by overheat remain. Herein, in order to minimize the risk of high-temperature induced ignition, a flame retardant Aramid nonwoven fabric was attempted to combine with the highly conductive MXene, where an intimate interface was constructed through their inherent abundant functional groups and the assisted plasma treatment. Interestingly, a very lightweight wearable heater with electromagnetic interference shielding (EMI efficiency of 35.7 dB for single-layer fabric), electrothermal conversion (up to 263 °C in 76 s at a supply voltage of 5 V) and photothermal conversion (up to 107 °C after irradiation for 175 s at light intensity of 125 mW cm−2) properties was achieved. These integrated properties arose from the interlacing conductive network cooperated by nonwoven fabric and stacked MXene nanosheets, which facilitated the multiple reflection and absorption of electromagnetic waves or light, as well as the low thermal conductivity. More importantly, the newly formed physical barrier from carbonization of the MXene further enhanced the flame retardancy of nanocomposite fabrics, guaranteeing the security in use. This research provides a versatile yet efficient path to fabricate the new generation of safe wearable MXene-based heater, which will expand their working temperature range.