Green polyphenol-based photothermal interfacial evaporation systems toward solar water production.

In recent years, photothermal interface water evaporation technology has shown great application prospects due to its advantages of sustainability and high efficiency. With the rapid development of this frontier field, a variety of photothermal materials have been developed and widely explored. Among them, polyphenol-based photothermal materials are drawing great attention in the development of high-performance interface evaporators with their advantages of being green, economical, versatile, and scalable, leading the next hotspot and frontier. Therefore there is an urgent need to update the wider scientific community on recent advances in this field. In this review, three distinct functions of polyphenols including adhesion, secondary reactivity and photothermal properties are first discussed, since these functions are vital for designing photothermal interface evaporation systems (PIES). Furthermore, structure–activity relationships and the unique advantages of polyphenols in constructing PIES are emphasized in this part. Subsequently, according to the main functions of polyphenols in PIES, the roles of polyphenols are introduced and categorized into four application forms: (a) as intermediate layers to introduce photothermal materials; (b) realizing hydrophilic modification in PIES; (c) as photothermal materials without substrates in PIES; (d) as photothermal coatings. Then some representative applications of polyphenols such as achieving confinement capillarity, designing complex 3D evaporators, and constructing multifunctional PIES are highlighted, which can further exhibit the distinct advantages of green polyphenol-based photothermal materials in improving the water evaporation performance. Finally, the challenges and opportunities for the future development of polyphenol-based interfacial water treatment for freshwater production are discussed. [ABSTRACT FROM AUTHOR]