Beyond evaporation enthalpy: Why interfacial water evaporation defies thermodynamic predictions

Interfacial solar steam generation (ISSG) leverages solar energy, a sustainable and renewable resource, to facilitate the evaporation of seawater or other water sources, thereby enabling the collection of condensed freshwater. This approach presents a nearly zero-energy solution for the production of potable water, offering a promising alternative to mitigate the global freshwater crisis. Recent advancements have led to the development of high-performance evaporative materials, grounded in theories such as water cluster evaporation and other water activation mechanisms. These materials exhibit evaporation rates that exceed the thermodynamic limits of conventional processes, a phenomenon referred to as super-evaporation. Although there remains ongoing debate regarding the theoretical underpinnings of this phenomenon, a growing body of evidence suggests that the evaporation rate at the interface can indeed surpass the theoretical limits defined by classical models. This paper seeks to re-evaluate the ongoing debates and advancements surrounding the theory of reduced evaporation enthalpy, or the super-evaporation effect, and offers a refined categorization of the interfacial evaporation process to reassess the underlying theories. We highlight the critical role of interfacial processes in the super-evaporation effect, with the aim of encouraging further research focused on the evaporation interface to deepen the understanding of this phenomenon within ISSG systems.