Breathable and superhydrophobic photothermic fabric enables efficient interface energy management via confined heating strategy for sustainable seawater evaporation

Achieving solar-heating-enabled sustainable water purification from seawater is considered a promising strategy for alleviating the water crisis worldwide. Since preventing salt contamination becomes a crucial consideration in practical application, extensive efforts have been devoted in recent years. However, there has been an urgent push to realize both efficient and stable seawater evaporation in a simple and scalable way. Here, we present a solar-enabled confined heating strategy to efficiently purify seawater, in which system the self-closed cover is composed of breathable, photothermal, and superhydrophobic fabric (PSHF). The confined heating strategy can remarkably reduce heat conduction loss during the evaporation process via an effective energy management. Note that when the thickness of the evaporator is optimized to 4 mm, the heat conduction can reduce to 0.98%, and the total heat loss is only 7.1%. As a result, the evaporation rate can be reach up to 1.49 kg/m2/h with the evaporation efficiency of 91.68% under 1 sun irradiation. The superhydrophobic properties of the photothermal layer can also endow the evaporators with good salt rejection performance. In our system, the PSHF can significantly endure salt pollution and remain stable under long-term evaporation of 12 h. Furthermore, this system can also maintain long-term salt-rejecting stability for evaporation sustainability, demonstrating significant potentials in stable and efficient seawater purification.

Automated summary

The study proposed a solar-enabled confined heating strategy for efficient seawater purification, utilizing effective energy management to maintain high efficiency and stability in the evaporation process.