Abstract
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•Bilayer evaporator composed of MOFs-derived carbon on wood sponge is prepared.•The designed architectures boost the solar-thermal interfacial evaporation performance.•The evaporator can extract groundwater from low moisture environment.
Soil-water extraction based on interfacial solar-thermal technology is a promising strategy to provide affordable freshwater in remote and poor inland areas. A double-layer solar evaporator is prepared on a wood sponge with a one-step brush-printing coating of zeolitic imidazolate framework-8 (ZIF-8)-derived nanostructured carbon. In this typical architecture, the ZIF-8-derived carbon coating inherits the original porous, dodecahedral framework, thus forming a chapped, rough morphology that synergistically promotes photothermal conversion. Wood sponges manufactured from raw wood offer privileged water-extraction advantages, including an abundance of super hydrophilic channels that ensure efficient bulk-water pumping and steam release. The double-layer solar evaporator shows high sunlight absorbance (∼97.8 %), low thermal conductivity (0.12 W m−1 K−1), stronger capillary force, and rapid water transport (30 cm min−1). Consequently, apparent pure water-evaporation and soil water-extraction rates reach 1.42 and 0.57 kg m-2h−1 under a one-sun light intensity, respectively. Therefore, the ZIF-8-based wood sponge can efficiently achieve interfacial evaporation and soil water extraction, providing a novel pathway for obtaining clean drinking water in arid inland areas.