Coating sponge with a hydrophobic porous coordination polymer containing a low-energy CF3-decorated surface for continuous pumping recovery of an oil spill from water

Abstract

For the remediation of oil spills and organic solvent leakage into water, it is desirable to develop not only advanced sorbents with a high adsorption capability but also labor- and time-saving apparatuses that can work continuously without human intervention. In this work, we synthesized a novel and highly stable porous coordination polymer (PCP, also called metal-organic framework), University of Science and Technology of China-6 (USTC-6), with a corrugated -CF3 surface that features high hydrophobicity. The uniform growth of USTC-6 throughout a graphene oxide (GO)-modified sponge was achieved and yielded a macroscopic USTC-6@GO@sponge sorbent, which repels water and exhibits a superior adsorption capacity for diverse oils and organic solvents. Remarkably, the sorbent can be further assembled with tubes and a self-priming pump to build a model apparatus that affords consecutive and efficient oil recovery from water. The easy and fast recovery of oils/organic solvents from water based on such an apparatus indicates that it has great potential for future water purification and treatment. A non-stick coordination polymer coating helps sponges absorb and recover up to 40 times their own weight in oil under extreme temperatures. Using passive sorbents to clean up toxic spills normally requires specially engineered materials, such as biomimetic surfaces with nanoscale rough features, to repel water molecules and attract oil particles. Now, Hai-Long Jiang from the University of Science and Technology of China and co-workers have developed a way to achieve these properties using porous coordination polymers containing copper ions and fluorinated organic ligands. After dipping a commercial sponge in graphene oxide to enhance copper binding, the team grew their coordination polymer coating in situ and found it yielded a corrugated surface with high hydrophobicity. Intriguingly, a prototype assembled from the coated sponge and a self-priming pump enabled labor-free cleanup of oil spills from water. A hydrophobic porous coordination polymer (PCP) has been synthesized and its growth throughout the graphene oxide (GO)-modified sponge yields a macroscopic PCP@GO@sponge sorbent, which repels water and exhibits superior adsorption for diverse oils. Remarkably, the sorbent is further assembled with tubes and a self-priming pump to build a model apparatus that can afford consecutive and efficient oil recovery from water.