A solar-driven self-repairing sponge for efficient recovery of crude oil

Solar-heated absorption has become an effective technique to handle the crisis of crude oil spill. Although photothermal absorbents could efficiently clean up crude oil in situ, oil recovery methods such as squeezing absorbents have a negative impact on structural integrity and performance of absorbents, shortening the service life of the device. Herein, a solar-driven carbon-doped self-repairing polyurethane sponge (CSPU) is fabricated for absorption and recovery of crude oil. Chitosan-derived N-doped porous carbon (NPC) as photothermal filler and 2-hydroxyethyl disulfide (HDES) as chain extender are introduced into sponge in situ through free foaming. The firm load of NPC endows CSPU with good light absorption of 97.1% and a stable photothermal conversion performance. Additionally, the solar-driven self-repairing property promotes CSPU to timely repair the structural damage caused in oil recovery process. Consequently, CSPU exhibits a high crude oil absorption of 23.5 g/g, and it still maintains a good oil absorption and recovery efficiency after friction, ultrasonic treatment or multiple absorption-recovery cycles. This strategy combining photothermal oil absorption and solar-driven self-repairing provides a sustainable and durable solution for addressing crude oil spills. [Display omitted] •Facile method for photothermal polyurethane sponge with all-in-one design•Sponge could absorb high-viscous crude oil through photothermal conversion.•Crude oil recovery was possible by compressing absorption saturated sponge.•Photothermal effect induced sponge to repair its damaged structure caused by compression.•The stable absorption (23.5 g/g) and efficient recovery of oil were achieved.