Superhydrophobic Co-MOF-based sponge for efficient oil-water separation utilizing photothermal effect

• Published in: Journal of hazardous materials 2024-05, Vol.469, p.134090-134090, Article 134090
• Main Authors: He, Xuanting, Lu, Jihan, Liu, Jiaxiang, Wu, Zixuan, Li, Boyu, Chen, Zhong, Tao, Wenquan, Li, Zhuo
• Format: Article
• Language: English
• Subjects: absorbents; absorption; Crude oil recovery; density functional theory; hydrophobicity; melamine; Melamine sponge; oil spills; Oil-water separation; oils; petroleum; Photothermal materials; polydimethylsiloxane; solar radiation; surface temperature; viscosity
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.134090

Effectively addressing crude oil spills remains a global challenge due to its high viscosity and limited flow characteristics. In this study, we successfully prepared a modified sponge (PCP@MS) by embedding the photothermal material of Co-HHTP and coating the melamine sponge (MS) with low-surface-energy polydimethylsiloxane (PDMS). The PCP@MS exhibited outstanding hydrophobicity with WCA of 160.2° and high oil absorption capacity of 59–107 g/g. The PCP@MS showed high separation efficiency of 99.2% for various oil-water mixtures, along with notable self-cleaning properties and mechanical stability. The internal micro-nano hierarchical structure on the sponge surface significantly enhanced light absorption, synergizing with the photo-thermal conversion properties of Co-HHTP, enabled PCP@MS to achieve a surface temperature of 109.2 °C under 1.0 solar light within 300 s. With the aid of solar radiation, PCP@MS is able to heat up quickly and successfully lowering the viscosity of the surrounding crude oil, resulting in an oil recovery rate of 8.76 g/min. Density functional theory (DFT) calculation results revealed that Co-HHTP featured a zero-gap band structure, rendering advantageous electronic properties for full-wavelength light absorption. This in situ solar-heated absorbent design is poised to advance the practical application of viscous oil spill cleanup and recovery. [Display omitted] •PCP@MS possesses remarkable self-cleaning, chemical and mechanical stability.•PCP@MS exhibits efficient oil-water separation and high absorption capacities.•Zero-gap band structure of Co-HHTP enhances PCP@MS's photothermal performance.•The recovery rate of PCP@MS exceeds 92% over 10 cycles of crude oil absorption.•PCP@MS is capable of remediating high-viscosity crude oil at a rate of 8.76 g/min.