Research Progress on Material, Preparation, Properties, and Water Purification Applications of Solar Energy‐Driven Hydrogels

ABSTRACT The global water resource crisis is continuing to intensify, and it is urgent to develop low‐energy consumption and sustainable water purification technologies. Traditional water purification technologies can address the issue of water shortage. However, these traditional water purification technologies have many limitations, including high energy consumption, secondary pollution, etc. Solar‐powered water purification technology has become a current research hotspot due to low cost, high efficiency, and environmental friendliness. Solar‐driven hydrogels (SDHs) with high hydrophilicity and porous structure, as the emerging water purification materials, can efficiently convert solar energy into thermal energy through photothermal conversion, thereby enhancing the efficiency of interface evaporation, which provides innovative solutions for seawater desalination and wastewater treatment. This article systematically reviews the advanced substrate materials and photothermal agents utilized in SDHs. Moreover, this review comprehensively introduces the preparation strategies and mechanisms of SDHs. Furthermore, this paper comprehensively explores the design principles for enhancing the efficiency of light‐to‐heat conversion and the rate of water evaporation, and improving mechanical strength, durability, and salt resistance. Finally, the review discusses the practical applications of SDHs in seawater desalination, heavy metal ion removal, organic dye degradation, etc., while exploring their innovative roles in multi‐level solar energy utilization and water resource recovery.