Photothermal superhydrophobic LA-MOF@PDA@MS sponge for offshore crude oil recovery

With the rapid development of industrial activities, oil spills have occurred frequently at sea, causing increasingly severe ecological damage and environmental pollution. However, traditional superhydrophobic sponges can only adsorb low-viscosity oils and are ineffective for high-viscosity crude oils with poor fluidity. Therefore, there is an urgent need to develop novel materials capable of effectively addressing crude oil spills. In this paper, LA-MOF was prepared by modifying zirconium-based metal-organic framework (UiO-66-NH₂) with lauric acid (LA), and a photothermal superhydrophobic sponge (LA-MOF@PDA@MS) was fabricated by sequentially depositing polydopamine (PDA) and LA-MOF onto melamine sponges (MS). The resulting LA-MOF@PDA@MS exhibits excellent water repellency, with a water contact angle (WCA) of 155.5°, along with good self-cleaning properties, chemical stability, and mechanical durability. The modified sponge demonstrates an oil absorption capacity ranging from 28.60 to 56.83 g/g, with separation efficiencies exceeding 97 % for the select oils. Moreover, the LA-MOF@PDA@MS exhibits remarkable photothermal performance, capable of elevating its temperature to 68.3 °C within 300 s under simulated sunlight irradiation. The heating capability significantly reduces the viscosity of crude oil, enabling efficient absorption. The sponge achieves a saturated crude oil uptake of 60.7 g/g with a transfer rate of 5.49 g/min. Furthermore, the modified sponge displays excellent anti-icing and antimicrobial properties, further extending its service life in practical applications. These superior characteristics make the LA-MOF@PDA@MS sponge a highly promising candidate for oil spill remediation.