Application and research progress of aerogel-based interfacial evaporation in solar desalination technology

With regard to environmental problems, freshwater resources are becoming increasingly important. As a technology to obtain freshwater resources, solar desalination has been widely considered because of its superiority in being clean and efficient. The interfacial evaporation aims to focus heat on the water body at the evaporation surface, thereby reducing heat loss and improving evaporation efficiency. However, the performance of interfacial evaporation is highly dependent on photothermal materials. Aerogel with low thermal conductivity, lightweight, and high porosity can meet the needs of photothermal conversion in the process of interfacial evaporation of water, solar radiation 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 questions could promote the improvement of the evaporation rate. Through the analysis of the process of photothermal conversion and the working principle, this paper systematically reviews and expounds on 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 the existing configuration is summarized. According to the different functions of the structure, the photothermal performance requirements of the corresponding materials are put forward. Finally, the future research direction in this field is prospected.