MXene-Mediated Dynamic Redox Initiation for the Rapid Fabrication of Gelled Adhesive Conductive Hydrogels for Applications in Self-Powered Flexible Electronics

Abstract Conductive hydrogels are promising soft materials for wearable electronics and self-powered sensing systems; however, their practical implementation is often limited by sluggish gelation kinetics, energy-intensive preparation processes, and insufficient integration of mechanical robustness, adhesion, and electrical functionality. Herein, we report a rapidly gelled MXene-reinforced adhesive conductive hydrogel, denoted as PAHM (PAA-PHEMA-MXene), constructed through a MXene/Fe3+/ammonium persulfate redox initiation strategy. The redox-active MXene nanosheets promote the decomposition of persulfate under ambient conditions, enabling fast free-radical polymerization of acrylic acid and hydroxyethyl methacrylate without an external energy input. Meanwhile, MXene nanosheets serve as multifunctional nanofillers and interfacial interaction sites, while Fe3+ coordination, hydrogen bonding, and gelatin association synergistically reinforce the polymer network. As a result, the PAHM hydrogel can be formed within 30 s and exhibits a tensile strength of 525 kPa, an elongation at break of 860%, good cyclic stability, and strong adhesion to diverse substrates, with a shear adhesion strength of 128 kPa on copper foil. Benefiting from its combined stretchability, adhesion, and conductivity, the hydrogel was further employed as a flexible electrode for a triboelectric nanogenerator. The resulting PAHM-TENG delivered an open-circuit voltage of 130 V at a contact frequency of 3 Hz, successfully powered 27 light-emitting diodes and a commercial calculator and maintained stable electrical output over 10800 cycles of continuous operation. In addition, the PAHM hydrogel showed rapid electromechanical response and potential for wearable motion monitoring. This work provides a facile material design strategy for rapidly formed, mechanically durable, and adhesive conductive hydrogels toward self-powered flexible electronics.