Vertically extended cylindrical wood scrolls with guided water transport for salt-resistant all-day vapor generation

Three-dimensional solar vapor generators offer significant potential for enhancing evaporation efficiency, yet maintaining continuous and efficient water transport in vertically extended structures remains a critical limitation. To address this challenge, we develop a cylindrical evaporator by rolling thin wood veneer sheets into a scroll structure. This design creates vertically aligned and radially interconnected transport pathways, enabling efficient capillary-driven water supply over extended heights while suppressing localized salt accumulation at the evaporation interface. Further, the elongated geometry increases the exposed surface area and promotes ambient thermal energy-assisted evaporation (dark evaporation). The 40 cm-tall evaporator achieved an impressive evaporation rate of 35.8 kg m −2 h −1 under 1 sun illumination, with a substantial fraction of the total evaporation originating from dark evaporation, highlighting the capability of the vertically extended 3D structure for enhanced overall evaporation performance. We demonstrate a proof-of-concept integration into a solar-powered desalination and plant cultivation system, highlighting its strong potential for practical use in water-scarce environments.