Solar-driven evaporators for water treatment: challenges and opportunities
Solar-driven evaporation is an emerging process to acquire freshwater from saline water or wastewater, in which photothermal materials play a crucial role. Significant effort has been devoted to promoting energy conversion efficiency by material and device design. In the current review, we discuss the major factors affecting evaporator efficiency and long-term performance, including selection of photothermal materials, promotion of evaporation efficiency, and solutions to the problem of scaling. Both the material components and structure will affect the absorption and reflection of the incident light, and the evaporation efficiency can be enhanced by reducing heat loss, enlarging surface area, and recycling latent heat. Scaling can be addressed by tailoring surface properties and structure.