Achieving Ultrahigh Voltage Over 100 V and Remarkable Freshwater Harvesting Based on Thermodiffusion Enhanced Hydrovoltaic Generator

Evaporative hydrovoltaic generators hold significant potential for alleviating water-energy crisis, but low output voltage configurations due to the slow phase transition rate of water molecules and the intricate nature of integration limit their applications. Herein, a lotus-inspired interfacial evaporation-driven hydrovoltaic generators (IEHVG) is developed for efficient generation of water vapor and electricity from seawater instead of freshwater and achieves an ultrahigh voltage output higher than 100-volt level through forested IEHVG integration. The biomimetic hydrogel is developed with specific liquid transport channels, graphene quantum dots/MXene nanocomposites, and gradient hydrophobic interface for highly enhanced photothermal evaporation and electricity generation by mimicking the transpiration process of a “stems-leaves of lotus”. The synergistic thermodiffusion effect leads to the output power density of IEHVG reaches up to 45.6 µW cm −2 and can power electronic devices or charge commercial supercapacitors. The freshwater-electricity cogeneration integrated system consisting of 192 IEHVG units can harvest a record-breaking voltage reaching 105 V and a high freshwater harvesting rate up to 2.0 L m −2 h −1 from seawater in a well-lit outdoor area. This work demonstrates that IEHVG offers a novel concept for modular freshwater and high-voltage power sources access on offshore work platforms.