Highly hydrophobic F-rGO@wood sponge for efficient clean-up of viscous crude oil

With the increasing occurrences of industrial oily wastewater emissions and crude oil spills, the deteriorated global environment and ecosystems have attracted a great deal of attention worldwide. Herein we report a highly hydrophobic balsa wood sponge wrapped with fluoroalkyl silane modified reduced graphene oxide (F-rGO@WS) for efficient clean-up of all kinds of oils including viscous crude oil from water. The F-rGO@WS possessed excellent water repellency with a water contact angle of 145°. Owing to high hydrophobicity and longitudinal channels, the F-rGO@WS was successfully applied for separating oil-water mixtures, and the separation efficiency reached 99.0%. Furthermore, the F-rGO@WS also possessed quick electrothermal capability and could be utilized as a filter to efficiently separate viscous crude oil from water by means of the generated Joule heat under a low voltage, and the separation rate was about 10 times higher than that without voltage. Our findings stand out a new tool to fabricate functional natural materials and exhibit great potential in practical applications such as water pollution control and clean-up of viscous crude oil.