Sustainable generation of electricity using carbonized lignin/thermoplastic polyurethane composite films in water

Harvesting energy from water/carbon interfaces represents an eco-friendly approach to addressing the global energy crisis. Unlike conventional nanogenerators utilizing carbon nanomaterials, which typically require integration into specific systems with external pumps for liquid flow, this study presents the fabrication of a novel water-driven energy generator (WEG) utilizing composite films that integrate carbonized lignin, with varying oxygencontaining groups, and thermoplastic polyurethane in an aqueous environment. Upon optimization, the WEG demonstrates remarkable performance, achieving stable output voltage and current of 210 mV and 1.04 μA, respectively. The WEG’s output voltage demonstrated remarkable stability and reproducibility during numerous cyclic bending tests. Furthermore, by simply connecting eight WEGs in series, an elevated voltage of 1.63 V can be achieved, and these scalable units have the capability to directly power commercial electronics, such as light-emitting diodes. This energy conversion technology may provide new insights into the design of WEGs capable of harvesting water energy.