Hydrogel‐Based Solar‐Driven Interfacial Evaporation and Seawater Desalination

Abstract Solar‐driven interfacial evaporation (SDIE) for freshwater production is regarded as a sustainable and promising desalination technology capable of effectively addressing freshwater scarcity. Due to their high adaptability and synthetic modifiability, hydrogels can be optimized to meet the diverse requirements of efficient solar evaporators. Despite significant progress in the design and fabrication of hydrogel‐based solar evaporators, there remains a lack of comprehensive summaries and reviews in this field. In this paper, recent advancements in hydrogel‐based evaporators for solar‐driven seawater desalination, ranging from material selection to structural design, are systematically reviewed. First, the unique state of water molecules is elucidated within hydrogels and discusses how altering their morphology and structure through fabrication methods can enhance water evaporation efficiency. Subsequently, the design principles of hydrogel‐based solar evaporators, focusing on high light absorption performance, water transport capacity, heat management, regulation of evaporation enthalpy, utilization of environmental energy, and resistance to salt accumulation, are summarized. Finally, based on current findings and analyses, an overview of the research progress of hydrogel‐based evaporators in seawater desalination and offer insights into their future development is provided.