Abstract
Interfacial solar steam generation (ISSG) employed for seawater desalination and wastewater purification shows great promise to alleviate global freshwater scarcity. However, simultaneous optimization of water transfer direction in a cost-effective and reliable ISSG to balance thermal localization, salt accumulation, and resistance to oilfouling represents a rare feat. Herein, inspired by seabird beaks for unidirectional water transfer, eco-friendly and cost-effective plant extracts, sodium alginate, and tannic acid, are selected for crafting an innovative Sodium Alginate-Tannic Acid Hemispheric Evaporator (STHE). The STHE aligned with centripetally tapered channels ensures one-directional water flow and effectively inhibits downward heat transfer, thereby boosting energy efficiency. Additionally, the integration of one-way water supply in tapered channels with interfacial evaporation of STHE, mimicking plant transpiration, collaboratively facilitates upward water transfer for a reliable solar-driven water evaporation rate of ≈2.26 kg m(-2) h(-1) under one sun irradiation. Even in a brine of 15.0 wt % solution, no salt crystals are observed on the surface of STHE. Hemispheric structure and superhydrophilicity are conducive to oil repellence. This work provides pivotal inspiration for constructing next-generation solar generators of high-efficiency, salt-tolerance, and anti-oil-fouling.