Solar-driven oil spill recovery using a carbon dots/loofah sponge

Oil spills are considered serious environmental disasters, causing various long-term negative impacts on human and marine life. Therefore, the development of absorbent materials to treat oil spills in a safe and environmentally friendly way is essential. Loofah is a widely available natural product in tropical countries, and due to its low cost and biodegradability, it is used in numerous applications, including food, handicrafts, and cleaning sponges. Owing to its superior porosity, loofah shows potential as a sorbent for oil spill treatment. Herein, we report a hydrophobic cellulose sponge based on a plasma-treated/carbon dots/loofah sponge (P-CLS), which is prepared through a carbon dot (CD) coating process, followed by a nonthermal plasma treatment. The surface temperature of P-CLS can reach up to 55 °C under 1 kW m^-2 irradiation, resulting in a faster oil transfer rate into the loofah's structure. This sponge demonstrates excellent absorption capacities of 6.6 g g^-1 and 6.0 g g^-1 in the dark and under 1 sun irradiation, respectively. Furthermore, P-CLS, with a CD-coated surface and a highly porous structure, shows a remarkable ability to release oil naturally, which reduces the energy required for the recovery process. The sponge achieves a self-releasing efficiency of 41.67%. This work provides a promising approach for practical oil spill remediation.