LS-CD/Fe³⁺-Initiated Conductive, Elastic, Self-Healing Hydrogels for Triboelectric Nanogenerators

Hydrogel-based triboelectric nanogenerators (TENGs) are promising for wearable electronics but face challenges such as high-energy fabrication processes, environmental toxicity risks, and limited self-healing efficiency. Here, we propose a sustainable strategy leveraging lignosulfonate-graft-β-cyclodextrin (LS-CD)/Fe 3+ dynamic oxidation and coordination system and host–guest interactions to fabricate multifunctional conductive hydrogels. The LS-CD/Fe 3+ system activates ammonium persulfate (APS) under mild conditions, enabling rapid polymerization of N -isopropyl acrylamide (NIPAM), acrylic acid (AA), and adamantane acrylate (ADA) monomers. Notably, the thermoresponsive phase transition behavior of NIPAM plays a critical role in enhancing triboelectric output. Above its volume phase transition temperature (VPTT), the incorporation of hydrophobic isopropyl moieties markedly improves triboelectric performance, with the enhancement mechanism principally attributed to their dual function in inducing rapid hydrogel volume shrinkage and promoting effective charge accumulation. Synergistically, metal coordination, hydrogen bonding, and β-cyclodextrin/adamantyl (β-CD/AD) host–guest interactions establish a robust dynamic network. This network not only addresses LS aggregation but also enhances the ionic conductivity to 0.59 mS/cm. The hydrogel demonstrates substantial stretchability (743% strain), rapid self-healing (96% efficiency within 1 h), and temperature sensitivity. The resultant single-electrode TENG achieves a high-output voltage (Voc) of 206 V and a transferred charge (Qsc) of 43 nC, demonstrating efficient mechanical energy harvesting. By integrating human motion sensing with energy storage capabilities, this study establishes an eco-friendly high-performance wearable electronic platform that achieves efficient capture of low-frequency energy while resolving the performance trade-offs among mechanical properties, self-healing efficiency, and electrical output characteristics.