Low-temperature carbonization synthesis of carbon-based super-hydrophobic foam for efficient multi-state oil/water separation

In view of the complexity and diversity of multi-state oils, the development of green and low-cost materials with high selectivity to oils has important ecological significance in the polluted water treatment. Herein, a simple method was proposed to develop large-scale production of superhydrophobic sponges (CPMF200 sponges) for high-efficiency oil/water separation under different complex environments. The as-prepared CPMF200 sponges possessed many superior properties, including high roughness, well-developed porosity, good thermal stability, excellent chemical stability, and superhydrophobic properties (water contact angle is 152°), which is conducive to high oil adsorption capacity (up to 70–179 times of its own weight) and oil-water separation. More importantly, the CPMF400 sponge has an excellent photothermal conversion capability to improve the fluidity of high viscosity oil for oil recovery. Based on a simple synthesis method, it exhibits high-efficiency absorption of multi-state oils and excellent oil-water separation performance and strongly proves their application prospects in treating oily wastewater. [Display omitted] •Sodium hydroxide pretreatment greatly reduces the temperature required for the preparation of hydrophobic sponges.•The CPMF sponge presented superhydrophobic properties and excellent oil absorption performance.•The CPMF sponge can quickly separate oil and water in a simulated turbulent environment.•The black sponge can quickly clean high-viscosity crude oil under the driving of solar energy.