Novel and facile fabrication of hydrophobic sponge for the efficient adsorption of marine crude oil by photothermal conversion

With the acceleration of the globalization of world maritime trade, the oil is largely transported. Whereas, the oil spill inevitably occurs during transportation. This not only causes the waste of energy, but also has a huge impact on the ecology. Therefore, it is imperative to develop efficient adsorbent to recover the leaked crude oil. In this study, a new and facile adsorption material was introduced for the treatment of offshore crude oil leakage. This material combined the hydrophobic modification of polydimethylsililane (PDMS) with the loadings of graphene (GR) and ferriferrous oxide (Fe₃O₄) over melamine sponge (MS), providing it with excellent hydrophobic/oleophilic and photothermal conversion properties. It revealed that the MS/PDMS/GR + Fe₃O₄ presented the hydrophobic property with the water contact angle of 147° and superior self-cleaning performance, effectively separating the oil and water mixture with the separation efficiency of up to 99 %. In addition, its excellent photothermal conversion ability converted the light energy into heat energy, reducing the crude oil viscosity and improving the adsorption efficiency. Under one sun illumination (1.0 kW m⁻²), the adsorption capacity of the MS/PDMS/GR + Fe₃O₄ for the high viscosity crude oil reached to 20.7 g_{crude oil}/g_sorbent, and the surface temperature of sample was more than 60 °C. This material exhibited excellent recycling properties after 10 adsorption and extrusion cycles, and displayed exceptional photothermal stability during light switch cycles (1.0 kW m⁻²). This MS/PDMS/GR + Fe₃O₄ offers novel concepts for designing and developing high-performance sorbents for the ocean oil leakage treatment.