Solar vapor generation technologies: fundamentals, innovations and applications

Growing water scarcity is increasing the need for sustainable water-production technologies that can operate with limited dependence on centralized energy and infrastructure. Solar-driven interfacial vapor generation (SVG) provides a promising pathway for decentralized water production by directly utilizing solar energy to drive water evaporation. Its performance is governed by several closely coupled processes, including solar harvesting, thermal management, water transport, and water activation, which are regulated by material chemistry and structures across multiple scales. We first introduce the fundamental working principles and evaluation metrics of SVG, and then discuss the materials and structural design strategies for controlling solar harvesting, thermal transport, water supply, and water activation. Particular attention is given to the physical basis of these processes and the relationships between material properties, multiscale structures, and evaporation performance. Emerging viewpoints on water activation and the corresponding materials chemistries are also discussed. We further consider the translation of these principles to water purification, agriculture, resource recovery, and energy or functional cogeneration. This Tutorial Review aims to equip researchers in the field of SVG with a thorough understanding of the fundamental evaporation processes, materials design principles, and key factors essential for advancing this technology toward sustainable water production.