All-in-One Hybrid Solar-Driven Interfacial Evaporators for Cogeneration of Clean Water and Electricity

Solar-driven interfacial evaporators (SDIEs) have recently attracted considerable interest due to their ability to harvest abundant solar energy and treat seawater/wastewater for both freshwater production and electricity generation. However, during photothermal conversion in SDIEs, a portion of the incident sunlight is inevitably wasted, which presents an opportunity for potential alternative applications. There are also other types of harvestable energy like interactions between absorber materials' surfaces and water/ions-called hydroelectricity (HE), as a form of renewable energy. This review paper provides an overview of studies focusing on utilizing SDIEs with a single structure capable of simultaneously producing freshwater and electricity, referred to as all-in-one hybrid SDIEs, with a particular emphasis on the HE power generation mechanism, which is the most commonly applied. An introduction to the photothermal conversion of sunlight into heat and fundamental aspects of the HE effect in hybrid SDIEs are discussed accordingly. The key results from studies on photothermal materials employed in all-in-one hybrid SDIEs are then explained and compared. This review will be concluded by spotlighting recent advancements, existing challenges, and promising opportunities that lie ahead for the materials used in these systems. The status and challenges are reviewed for all-in-one hybrid solar-driven interfacial evaporators that absorb sunlight to vaporize water for freshwater production and also offer the potential to generate electricity during operation based on interactions of surface and water/ions (hydroelectricity) and other mechanisms including electrochemical, piezoelectricity, pyroelectricity, salinity gradient, and triboelectricity. image