Harvesting Water Energy through the Liquid-Solid Triboelectrification.

The escalating energy and environmental challenges have catalyzed a global shift toward seeking more sustainable, economical, and eco-friendly energy solutions. Water, capturing 35% of the Earth's solar energy, represents a vast reservoir of clean energy. However, current industrial capabilities harness only a fraction of the energy within the hydrological cycle. The past decade has seen rapid advancements in nanoscience and nanomaterials leading to a comprehensive exploration of liquid-solid triboelectrification as a low-carbon, efficient method for water energy harvesting. This review explores two fundamental principle models involved in liquid-solid triboelectrification. On the basis of these models, two distinct types of water energy harvesting devices, including droplet-based nanogenerators and water evaporation-induced nanogenerators, are summarized from their working principles, recent developments, materials, structures, and performance optimization techniques. Additionally, the applications of these nanogenerators in energy harvesting, self-powered sensing, and healthcare are also discussed. Ultimately, the challenges and future prospects of liquid-solid triboelectrification are further explored.