Deep Eutectic Solvent-Assisted In Situ Wood Delignification: A Promising Strategy To Enhance the Efficiency of Wood-Based Solar Steam Generation Devices

Wood-based solar steam generation devices (W-SSGDs) show great promise for desalination and wastewater treatment because they are inexpensive and sustainable. Technical methods for enhancing the efficiency of W-SSGDs have, so far, mainly focused on the optimization of solar-to-thermal conversion efficiency, whereas the properties of the wood matrix have been ignored. Here, we have designed a strategy using deep eutectic solvents to remove lignin from bulk wood in situ for the fabrication of a high-performance W-SSGD (DW-SSGD). Wood delignification increases the water transportation capacity while reducing thermal conductivity and conductive heat loss in the wood matrix. The improved properties of delignified wood allowed us to construct a high-performance DW-SSGD with a steam generation efficiency of 89% and an evaporation rate as high as 1.3 kg m-2 ti-1 at 1 sun (100 mW cm-2). To the best of our knowledge, the performance reported here is the highest for a W-SSGD under one solar irradiation.