Multifunctional MXene-doped conductive double network hydrogel for environmentally resistant triboelectric nanogenerator and wearable thermal management

Conductive hydrogels are ideal building blocks to fabricate wearable electronics. However, their performance still suffers from harsh environmental conditions. Herein, a self-healable, environmental temperature resistant, NIR light-induced photothermal responsive and conductive double network hydrogel (MXCNH) was prepared by integrating photothermal reagent of well-dispersible polydopamine-modified MXene (MXene@PDA) into a carboxymethylcellulose sodium (CMC Na) as the first network, flexible poly( N -(2-hydroxyethyl)acrylamide- co - N -isopropylacrylamide) P(HEAA- co -NIPAm) as the second network matrix in ethanol-water binary solution via UV polymerization. The optimized hydrogel showed excellent mechanical properties (stress/strain of 666.4 kPa/2141 %), adhesion (936 kPa for steel), and conductivity (0.61 S/m), enabling strain sensors with high gauge factor (2.05 at 200–400 % strain). Further, MXCNH hydrogel-based triboelectric nanogenerator (MX-TENG) exhibited enhanced 15.2 % V OC (158.44 V at 61.2 °C) upon a NIR light irradiation. MX-TENG also generated favorable electrical output performances (open-circuit voltage: V OC  = 126.61–178.62 V) and long-term stability (stable after one month storage) in ranging from −20 °C to 50 °C. These remarkable comprehensive properties enabled applications in self-powered sensing and energy harvesting with a wide temperature range. Meanwhile, MXCNH hydrogel served as a wearable heater for NIR-triggered thermal management, demonstrating significant potential for clinical treatments.