Solar-driven self-heating PBAT/hollow carbon microsphere foam for high-viscosity crude oil spill remediation

Frequent crude oil spills, especially those involving highly viscous crude, pose serious environmental, economic, and safety challenges. The crude oil with limited fluidity under ambient conditions significantly hinders rapid cleanup and increases energy consumption during recovery. Therefore, we present a solar-driven, self-heating, and eco-friendly foam (P-PBAT/HCM) for fast absorption and efficient crude oil recovery. The foam is fabricated by incorporating hollow carbon microsphere (HCM) as photothermal fillers into the flexible environmentally-friendly poly(butylene adipate-co-terephthalate) (PBAT) matrix via thermally induced phase separation (TIPS), followed by polydimethylsiloxane (PDMS) dip-coating to impart hydrophobicity. The material demonstrates excellent hydrophobicity, compressive resilience and chemical stability. Due to the outstanding photothermal efficiency of HCM, the foam exhibits an average light absorption of 97.9% over the full solar spectrum and rapidly heats to 82 °C within 5 min at 1.0 kW m⁻² irradiance. This photothermal self-heating effectively reduces crude oil viscosity and accelerates absorption. When coupled with a pump-assisted system, the foam enables continuous crude oil spill recovery with a stable and high flux of 345 kg m⁻² h⁻¹ under outdoor environments. This foam offers a potential approach for crude oil spill remediation.