Solar Interfacial Evaporation Toward Multifunctional Water‐Energy Nexus Systems

The scarcity of freshwater resources has escalated into a pressing global challenge. Solar interfacial evaporation (SIE) has gained significant attention because of the abundance and environmental sustainability of solar energy. While SIE demonstrates promising potential, this technology currently faces limitations of residual thermal energy dissipation and restricted product portfolio. These inherent constraints have catalyzed innovative integration strategies that combine SIE with value‐added thermodynamic and chemical processes (e.g., SIE + hydrogen production). This study reviews the concept of “SIE + X,” which combines SIE technology with other processes or reactions, including electricity production, photocatalysis, metal recovery, and pollution removal. This review systematically examines recent breakthroughs in high‐efficiency cogeneration materials and device architectures, with particular emphasis on advanced photocatalytic mechanisms, innovative resource recovery pathways, and thermal energy cascade utilization strategies. Furthermore, it provides a perspective on developing standardized evaluation frameworks, improving system design to enhance efficiency and stability, and advancing photothermal materials and catalysts. These efforts are crucial for enabling the widespread adoption of SIE technology as a sustainable solution to global freshwater scarcity.