Mechanistic Insights into Solar Evaporators for Enhanced Long-Term Salt Resistance of Hypersaline Brines

To address the persistent challenge of salt accumulation and clogging in solar evaporators, a comprehensive strategy aimed at reducing salt ion concentration at the evaporation interface by minimizing flow loss (mixing loss and friction loss) is proposed. The core principle is minimizing mixing loss to enhance the water supply efficiency to the evaporation interface, while also balancing friction loss influence by taking away salt ions from the evaporation interface. Utilizing this methodology, a novel solar evaporator that includes a millimeter-scale channel at its core, surrounded by a homogenized micro-porosity structure created using the projection microstereolithography technique is developed. The results demonstrate that the proposed solar evaporator achieves an exceptional evaporation rate of 3.42 kg m^-2 h^-1 in 20 wt.% hypersaline brines over a continuous operation period of 120 h under 1 sun irradiance. These results represent a significant achievement in the development of highly efficient and salt-tolerant solar evaporators.