The Water Behavior Chain: A Unified Framework for Solar Interfacial Evaporation

Confronting the global freshwater crisis, solar interfacial evaporation (SIE) has emerged as a sustainable desalination technology. However, prevailing research remains anchored in a material-centric or structural engineering innovation, treating water as a passive medium. This review proposes a unifying water-centric framework by introducing the concept of a "water behavior chain" that maps the complete journey of water, from water transport and water state regulation to interfacial evaporation and product management. We systematically elucidate how hierarchical regulation of this chain enables breakthrough performance: engineering of water supply pathways for optimal thermal management, synergistic effects to reduce evaporation enthalpy and enhance evaporation rates, and design of smart interfaces for the synchronous reuse of both salt and vapor to ensure long-term stability. Moving beyond freshwater production, we demonstrate how mastering the water behavior chain unlocks multifunctional SIE systems for synergistic water-energy cogeneration, selective resource recovery and water pollutant purification. This review not only fills a critical gap by placing water at the heart of SIE analysis but also provides a unified roadmap to guide the development of next-generation, high-performance, and intelligent solar evaporation technologies.