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

[Display omitted] •P-Fe3O4@CMS was fabricated via carbonization of melamine sponge and subsequent modification of PDMS/ Fe3O4.•P-Fe3O4@CMS owns superhydrophobicity and enables oil absorption selectivity, while its magnetic responsivity makes it possible for rapid positioning of the sponge towards oil spills.•P-Fe3O4@CMS displays outstanding solar/electro-thermal performance thanks to CMS itself, requiring no additional photo-thermal agents or conductive fillers and thus simplifying the preparation process.•The self-heating sponge could achieve high-efficiency and all-weather offshore oil spill cleanup under the combined assistance of Joule heating and solar effect. 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.