Tree‐Inspired 3D Biomimetic Evaporator for Efficient Solar Desalination and Automated Salt Collection with Zero Liquid Discharge

Abstract Solar‐driven interfacial evaporation has emerged as a sustainable strategy for high‐salinity brine treatment, yet salt crystallization on evaporators severely limits evaporation efficiency and long‐term stability. While most research focuses on enhancing evaporation rates and preventing salt accumulation, the economic and ecological value of simultaneous salt collection is often overlooked. Achieving both efficient evaporation and high salt collection remains a major challenge. Here, we present a tree‐inspired biomimetic evaporator (TBE) is presented that leverages co‐directional Marangoni flows, driven by synergistic thermal and solute gradients, to enable directional salt crystallization and autonomous salt collection. In a one‐week continuous test with 23 wt.% brine, the TBE achieved an exceptional evaporation rate of 6.29 kg m ⁻² h ⁻¹ , a salt production rate of 1.08 kg m ⁻² h ⁻¹ , an automatic salt detachment rate of 94.1%, and zero liquid discharge (ZLD). Moreover, the TBE exhibited a high freshwater production rate of 4.30 kg m ⁻² h ⁻¹ and a salt collection rate of 0.45 kg m ⁻² h ⁻¹ in outdoor tests. This work provides a scalable, energy‐efficient solution to address both freshwater scarcity and brine pollution, aligning with UN Sustainable Development Goals (SDGs) 6 (Clean Water) and 14 (Life Below Water) by eliminating harmful brine discharge and reducing reliance on fossil fuels.