Fresh water collection strategy: Invasive plant-based cellulose aerogels for highly efficient interfacial solar evaporation

Interfacial solar steam generation (ISSG) is promising technology to solve global scarcity of freshwater resources, hence highly efficient, robust photothermal conversion materials as key components for ISSG were urgently needed. Herein, the threat of invasive plant Solidago canadensis L. (SCL) to agricultural environment and ecosystem diversity was explored and further utilization was demonstrated by stripping and purification of raw SCL to three-dimensional crosslinked SCL-based cellulose aerogel (SCL-CA) with polyethylene glycol (PEG) as green cross-linking agent. After dopamine (DA) in situ polymerized on the SCL-CA surface, PDA@SCL-CA exhibits a high evaporation rate of 2.05 kg m−2 h−1 with photothermal conversion efficiency of 95.5 % under one sun upon the customized evaporation equipment with simulated seawater. The result is much better than that of other state-of-art samples due to the unique 3D-macro interlaced structure and hierarchical microcapillary structure of overpass bridge-shaped cellulose chains. The excellent outdoor experiment further demonstrated the practical application owing to the full solar spectrum absorption, superhydrophilicity, anti-salinity, robust structure, etc. Especially, the design strategy can be universal, and PPY@SCL-CA modified with polymerized pyrrole (PPY) can also work as a highly efficient photothermal material. The mild synthesis methods and abundant sources of raw material render it possible to fabricate efficient photothermal materials on a large scale, realizing the control of biological invasive species and resource utilization. Combining with the future upgrade of evaporator components, the heat conversion efficiency, water yield, and economic benefits of the evaporator would be further improved, which has broad application prospects in alleviating the freshwater crisis.