Easy hydrogel preparation with high-purity lignin separated from DES pretreatment with excellent-performance for moisture-electric generators and motion sensors

This study presents a rapid and easy method for preparing a multifunctional hydrogel composed of lignin obtained by deep eutectic solvent pretreatment (DESL), Al3+ and polyacrylic acid (PAA) in aqueous system. DESL with high purity proves to be an exceptional raw material for the production of hydrogel-based moisture-induced electricity generators (HMEG), surpassing alkali lignin in availability and lignosulfonates in versatility. The resulting hydrogel exhibits exceptional self-adhesive, flexible, plastic, and self-healing characteristics with a tensile strength of 1.57 MPa and a tensile rate of 1580%. A single HMEG generated impressive voltage of 2.78 V/cm-3 and current of 22 μA/cm-3, which can function as a motion-sensor without an external power supply. This study presents a novel approach aimed at maximizing the DESL value and expediting the development of a hydrogel moisture power generation device that is both cost-effective and efficient, while also considering ecological considerations.