Application and research progress of aerogels in solar desalination technology

Under the background of the global energy crisis and environmental problems, freshwater resources are becoming more and more important in the development of modern society. As a technology to obtain freshwater resources, solar desalination has been widely concerned because of its superiority in clean and efficient. Of which, the interface evaporation aims to focus heat on the water body at the evaporation surface, thereby reducing heat loss and improving evaporation efficiency. However, performance of interface evaporation is highly dependent on photothermal materials. Aerogel with low thermal conductivity, light weight and high porosity can meet the needs of photothermal conversion in the process of interfacial evaporation of water, light absorption and heat insulation, so it has become one of the ideal choices of photothermal materials. At present, the solar desalination technology based on aerogel is becoming a research hotspot, and there are certain core technologies that need to be broken, such as low water transfer rate, salt pollution precipitation, slow photothermal conversion, and short service life. Overcoming these key scientific questions could greatly promote the improvement of the evaporation rate. Through the introduction and analysis of the process of photothermal conversion and the working principle of evaporator, the author has systematically reviewed and expounded the research progress of related technologies in recent years. On this basis, the influence of surface structure design on evaporation rate is discussed, and the strategy selection of structural design factors based on existing configuration is summarized. According to the different functions of the structure, such as heat insulation and evaporation surface, the photothermal performance requirements of the corresponding materials are put forward. Finally, the future research direction in this field is prospected.