Evaporation Triboelectric‐Nanogenerator: Harvesting Low‐Grade Heat Energy from Ambient Environment

Abstract Although natural evaporation absorbs substantial thermal energy from the ambient environment, efficiently utilizing this high‐entropy energy remains challenging. Here, the first water evaporation‐induced triboelectric nanogenerator is proposed. It only uses tap water to harvest low‐grade heat energy from the surroundings to convert it into electricity. The natural evaporation of the liquid can generate unintermittent electricity with an open‐circuit voltage of 382 V, a peak power of 0.42 mW, and three orders of magnitude enhancement up to 59.7 mJ mL −1 after consuming the same amount of tap water compared with the droplet‐based electricity generators. After which, the excellent power output lights 2 W LED and drives wearable electronic devices. This device also inhibits carbon steel materials' corrosion in solutions through the evaporation effect of the salt water on the spot. The present study provides novel insights for triboelectric nanogenerators regarding energy sources and promotes the practical application of evaporation‐power generation technology.