Interfacial solar evaporation for zero liquid discharge desalination

Interfacial solar evaporation is a sustainable and effective method that uses solar energy to produce freshwater. As this technology continues to develop, the ability of interfacial solar evaporators to tolerate high salt concentrations and achieve stable evaporation has gradually improved. Some evaporators can even achieve complete separation of water and solutes, resulting in zero liquid discharge. Here, we discuss strategies for interfacial solar evaporators for treating high-salinity wastewater and achieving zero liquid discharge. We particularly focus on representative management strategies, including timely removal of salt crystals and prevention of salt deposition on photothermal materials. Additionally, we present three design ideas for evaporators, including the fundamental principles behind these strategies. Current challenges and future research opportunities are proposed.