Overcoming Salt Crystallization During Solar Desalination Based on Diatomite-Regulated Water Supply

Solar evaporation as a sustainable technology has exhibited great potential to solve the shortage problem of water and energy. In this article, conductive ink EL-P-3040 (rich in poly(3,4-ethylenedioxythiophene), PEDOT) and diatomite were used as the composite functional layer to prepare a new type of solar evaporator, which showed excellent photothermal conversion and evaporation performance with the evaporation rate of 1.41 kg/m2 h and solar energy utilization of 88.6%. Furthermore, salt crystallization during solar desalination was effectively overcome. PEDOT segment at the evaporation interface could in situ heat the surrounding water molecules by efficient photothermal conversion. Diatomite as the hydrophilic medium was successfully embedded in the ink layer to construct water channels for water transportation to the evaporation interface. At the same time, the transport of salt ions was blocked by diatomite to suppress supersaturation of salt solution and eliminate the phenomenon of salt crystallization at the evaporation interface. The purpose of this study is to provide valuable reference for the practical desalination application of solar evaporation.