MOF-Derived nanoarchitectured carbons in wood sponge enable solar-driven pumping for high-efficiency soil water extraction

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 (similar to 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(-2)h(-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.

Automated summary

Soil water extraction based on interfacial solar-thermal technology using a double-layer solar evaporator with a ZIF-8-derived carbon coating on a wood sponge can efficiently achieve evaporation and provide clean drinking water in arid inland areas. The wood sponge offers water-extraction advantages due to its super hydrophilic channels, while the carbon coating promotes photothermal conversion. The double-layer solar evaporator exhibits high sunlight absorbance, low thermal conductivity, stronger capillary force, and rapid water transport.