Metal organic framework enabled wood evaporator for solar-driven water purification

By utilizing sunlight, the interfacial solar evaporation system is promising for seawater desalination, wastewater decontamination and electricity generation. Herein, a copper-based metal organic framework (Cu-CAT) was coated on wood sheets to form a wood evaporator, and the wood substrate with a low thermal conductivity is in charge of continuous water transportation. The Cu-CAT layer was attached tightly to both the top and bottom surfaces of the wood substrate. The black Cu-CAT at top surface affords a broadband and strong light absorption, while the underwater superoleophobic Cu-CAT layer presents a high oil repellence. Through optimizing the wood substrate thickness, the wood evaporator (Cu-CAT/Wood) with a wood thickness of 10 mm displayed an evaporation rate of 1.80 kg m−2h−1 under simulated 1 sun illumination. Enabled by the Cu-CAT, the wood evaporator can be used for water purification from various sources (seawater, oil-, dye-, heavy metal- contaminated water and natural lake water). Importantly, the Cu-CAT/Wood could co-generate electricity induced by the solar vaporization process. This work will stimulate more studies on the structural designs of solar evaporators for drinkable water production and pollution abatement.