Novel high-capacity and reusable carbonaceous sponges for efficient absorption and recovery of oil from water

Ever increasing demand for crude oil has resulted in frequent accidents of oil spill. To effectively separate and recover spilled oil from water, there has been a dire need for effective absorbent materials. In this work, we synthesized an innovative hydrophobic and recyclable sponges using low-cost raw materials and by the unidirectional freeze-casting technique. The composite material showed unusually high capacities for various oil (up to 32.26 g g⁻¹) and organic solvents (up to 52.51 g g⁻¹). FT-IR and XPS analyses revealed a highly oriented inter-linked network of the polymers, which accounts for the high absorption capacities and strong mechanical stability. Upon regeneration, the sponges can be reused >5 times without a significant drop of the absorption capacity. Moreover, the sponges can collect spilled oil continuously from water surface with the aid of an oil-cleanup pumping device. Due to the facile and environment-friendly synthesis, high absorption capacity and thermal stability, the new materials hold potential for more cost-effective separation and recovery of crude oil or other hydrophobic organic pollutants from water.