Heat-driven all-weather oil spill cleanup by a multifunctional superhydrophobic carbonized sponge

Cleanup of crude oil spills generally faces challenge of high viscosity. Reducing it by virtue of photo-thermal or electro-thermal effect is considered promising to resolve this worldwide issue. However, constructing the photo-thermal or electro-thermal materials requires corresponding agents, leading to high cost and complex preparation process. Herein, a versatile, superhydrophobic, and magnetically responsive carbonized sponge (P-Fe3O4@CMS) is designed by pyrolysis and modification with polydimethylsiloxane (PDMS)/Fe3O4 nanoparticles (NPs). This sponge owns selective oil absorption with the capacity of 45.3 to 88.5 g/g. Its surface temperature can rise to 247 °C with 8 V voltage and to 92 °C under 1.0 kW/m2 irradiation, respectively. The self-heating function benefits from electro-thermal and photo-thermal conversion of CMS itself, enabling declined crude oil viscosity and thus enhanced absorption speed. Besides, P-Fe3O4@CMS has brilliant compressibility, allowing oil recovery via extrusion. Pump-assisted continuous oil recovery is feasible to favor a high flux of 785 kg m−2h−1 under the synergistic effect of 8 V voltage and 0.5 kW/m2 irradiation, making it viable for saving energy and efficient oil recovery despite weather conditions. Given the simple fabrication process and cost-effectiveness with 24/7 accessible work, P-Fe3O4@CMS exhibits great potential for oil spill remediation.