Green, Biodegradable, Underwater Superoleophobic Wood Sheet for Efficient Oil/Water Separation

[Image: see text] Superwettable (by water or oil) materials have been used in oil/water separation to cope with the growing oily industrial sewage discharge and oil spill accidents. The artificial superwetting materials for oil/water separation that have been previously reported are expensive, and using them usually causes secondary pollution, so practical, large-scale uses of those materials are limited. Here, we find that wood sheet shows underwater superoleophobicity and low oil adhesion in water, resulting from its strong capacity of absorbing water. A through-microhole array was created on the wood sheet surface by a simple mechanical drilling process. The prewetted porous sheet had great ability to separate the mixtures of water and oil with high separation efficiency. Wood is a low cost, green, and natural eco-friendly material; therefore, we believe that such a simple, low-cost, efficient, and green route of large-scale oil/water separation has great potential to practically solve the pollution problems caused by oil spill and oily industrial wastewater.