Multiphase solar evaporator for localized salt harvesting and in-depth water purification

Solar-driven interfacial evaporation (SIE) has been receiving more and more attention on the stage called “Sustainable Development”. However, pursuing a rational coexistence of steady-state evaporation, endogenous resource recovery, and water decontamination in solar evaporators is still a great challenge. To address this problem, a one-dimensional water transport pathway chitosan-based multiphase evaporator (OCHE) was fabricated for simultaneous Marangoni-driven salt mitigation and dye adsorption while solar vapor generation. Due to the efficient energy utilization and water supply, OCHE achieves a water evaporation rate of 1.767 kg m −2  h −1 with an energy efficiency of 96.87% under one sun illumination. More importantly, the 1D water pathway induces directional solute capillary convection and thermocapillary convection in evaporator when OCHE is working in high-salinity brine, leading to localized salt harvesting driven by Marangoni-driven liquid transport. Moreover, OCHE exhibits the good adsorption capacity for methylene blue (MB) and methyl orange (MO). This versatile multiphase evaporator provides a new insight into the design of next-generation eco-friendly, salt-resistant, and in-depth water purification solar evaporators.