Harvesting electricity from the multiple dynamic processes of water through the hierarchical structure of wood utilized for water transport

Hydrovoltaic power generation technology, which converts the chemical energy from ubiquitous moisture into electrical energy, represents a promising emerging green energy harvesting strategy. The incorporation of renewable biomass materials further enhances the appeal of this approach. In this study, an all wood-based hydrovoltaic electricity generator (WHEG) based on water migration is developed through simple chemical treatment of poplar wood. The removal of lignin releases micro- and nano-scale pores, while maleic anhydride (MAH)-mediated chemical modification enhances surface charge density, collectively improving the electrical output performance of the MAH modified delignified wood (MDW). The WHEG device achieves an open-circuit voltage (V_OC) exceeding 0.3 V during water infiltration and evaporation. Remarkably, the HEG device utilizing ZnC electrodes demonstrates a significantly higher V_OC of about 1.3 V and a power density of 6.2 μW/cm². WHEGs in series can power commercial electronics and self-powered systems. Integrated WHEG units enable customizable power outputs for direct energy storage or supply. Beyond electricity generation, the multifunctional MDW exhibits real-time responsiveness to water droplet movement, offering potential applications in leakage detection and rainfall monitoring. This work provides a novel pathway for designing efficient generators using sustainable materials, thereby expanding the application scope of hydrovoltaic technology.