Film-twist-yarn evaporator with durable salt resistance for efficient photo-electro-thermal desalination

Abstract

Electrothermally coupled solar steam generation (ESSG) is a promising desalination strategy for addressing freshwater shortage challenges. Most emerging ESSG devices achieve synergistic optimization by combining several functional components for photothermal conversion, electron migration, and water transport. However, complex streamlines and excessive energy loss have hindered their practical application. In this study, we developed a carbon nanotube/Tencel film-twist-yarn fabric (CTFF) evaporator as a single-component system for efficient and durable desalination. Film-twist-yarn engineering endowed the CTFF with strong mechanical robustness and desirable photo-electro-thermal conversion. Benefiting from its unique twisted structure, the balance between electron migration and water transport could be optimized by manipulating the fiber orientation and distribution. Overall, the CTFF exhibited an exceptional evaporation rate of 3.4 kg m−2·h−1 under 3 V DC input and 1 sun radiation. CTFF remained stable and intact over 30 desalination cycles even in 10 wt% brine. During outdoor practical application, CTFF achieved all-weather desalination performance with a high water collection of over 34 kg·m−2 in 3.5 wt% brine. This study offers a scalable single-component evaporator for durable high-concentration desalination with efficient photo-electro-thermal conversion.