A novel method for salt separation-crystallization and water recovery via photothermal evaporation

To address the challenges of salt interference and resource utilization difficulties in seawater desalination processes, there is an increasing demand for efficient separation of NaCl and Na₂SO₄. Inspired by the salt secretion mechanisms of mangrove ecosystems, we developed a cost-effective biomimetic system for salt separation and collection that synergistically integrates photothermal evaporation with ion-sieving processes and crystallization control mechanisms. This novel design achieves simultaneous separation and collection of NaCl at a single interface. The system demonstrates superior separation performance under high-salinity conditions, achieving a remarkable salt crystallization rate of 72 g m⁻² h⁻¹ in 20 wt% saline solution with a separation factor of 2.72 at a NaCl/Na₂SO₄ ratio of 3. The system maintained high-efficiency and stable operation during prolonged cycling experiments. By synergistically combining salt separation/collection with interfacial evaporation on a unified platform, this study presents an efficient and sustainable approach for salt fractionation that significantly advances the field of brine resource recovery.