Native Lignin Migration and Clustering in Wood: Superhydrophobic, Antimold, and Tribonegative Layers for Rain‐Driven Electrification

Abstract The development of wood‐based materials for energy harvesting, particularly triboelectric nanogenerators (TENGs), has recently attracted significant attention. Traditional strategies for wood‐based TENG primarily rely on delignification to enhance tribo‐positivity, overlooking the intrinsic potential of lignin and necessitating the use of fluoropolymers to maintain performance. In this study, the native lignin within the wood matrix is used to create a superhydrophobic, fully wood‐based tribonegative material (referred to as Lig‐wood), functioning as a liquid–solid triboelectric nanogenerator (L–S TENG) upon contact with water. Through a process of pretreatment and in‐situ regeneration, lignin undergoes migration, assembly, and redistribution within the wood's hierarchical architecture. This results in enhanced hydrophobicity (water contact angle 148°) and efficient surface charge transfer. The morphological and chemical changes significantly boost Lig‐wood's tribonegative performance, achieving a 7.5‐fold increase in voltage and a 6‐fold increase in current compared to unmodified wood. The Lig‐wood powers LEDs and digital timers under simulated rainfall, demonstrating its functionality as green energy harvesting material. Importantly, the surface‐localized lignin imparts self‐cleaning and antimold properties, supporting the potential for long‐term, outdoor use. By leveraging the inherent functionalities of lignin, this approach presents a sustainable strategy for rain‐driven energy harvesting, representing a significant advancement in green and renewable energy technologies.