Space-occupied 3D structure improves distilled water collection at the solar interface distillation

Recently, solar-driven interfacial distillation has rapidly developed into an effective technology for unconventional water treatment. Solar evaporator as the central part of the system was extensively investigated and achieved high light-to-heat efficiencies. However, the combination of interfacial evaporators and solar still in the application was rarely studied, and the phenomena inside the device during evaporation have yet to be revealed. Here, we designed an interfacial evaporator with a conical solar still unit to study the enhancement of water collection. The physical changes inside the device during natural solar irradiation were also revealed. In addition, the COMSOL Multiphysics as simulation software was applied to reveal the temperature variation of the system during solar motion. As a result, the condensate collection of the space-occupied 3D system is 2.5 times that of the plant system in the actual solar irradiation, which is even larger than the laboratory irradiation process. In addition to more solar energy absorption during the solar movement, the faster saturation of the humidity (more than 90%) due to the space occupation is also an important factor for the higher water collection capacity of the 3D system. This discovery would provide a reference for the design of the interfacial evaporator and evaporation device in the future and promote its practical application.