Upcycling papermaking waste into thermo-galvanic gel for harvesting waste heat and sunlight
Year: 2026
Type: article
Abstract: Efficiently converting low-grade heat (< 100 °C) into electricity remains a significant challenge. Moreover, most widely studied thermogalvanic electrolytes rely on redox couples containing toxic metal elements, which poses serious obstacles to developing non-toxic and environmentally sustainable energy conversion technologies. Herein, we present a high-performance thermogalvanic system which employs biobased sulfonated lignin (LS), a major component in paper industry black liquor and ammonium persulfate (APS) as the redox couple. Driven by quinone/hydroquinone redox reactions under a thermal gradient, the liquid electrolyte can convert heat into electricity with a Seebeck coefficient of 2.92 mV/K. Furthermore, the quasi-solid LS-APS-KOH/Poly(vinyl alcohol) (LSAK/PVA) gel prepared from gelation of such electrolyte with PVA further enhances the Seebeck coefficient to 4.3 mV/K, leading to an output power density of 976 μW/(m 2 ·K 2 ). Notably, by exploiting the intrinsic photothermal property of lignin, we demonstrate an integrated photo-thermo-electric conversion system on a unified material platform centered on lignin, opening new avenues for direct solar energy harvesting. This study establishes a novel “waste-to-energy” paradigm by valorizing industrial black liquor for advanced energy applications.
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: diamond
Awards: G359845647, G7097314172, G9000847552
OpenAlex ID: W7214939757