Superhydrophobic Copper Foam Modified with n-Dodecyl Mercaptan-CeO2 Nanosheets for Efficient Oil/Water Separation and Oil Spill Cleanup

Abstract

Efficient separation of oil/water with a simple and low-cost method is of great importance for the treatment of oily wastewater. In the current study, a facile one-step electrodeposition method was used to fabricate highly dense CeO₂ nanostructures on copper foam at a constant current density of 1.5 mA·cm–² for 20 min, which exhibited excellent superhydrophobicity and superlipophilicity after surface modification with n-dodecyl mercaptan (NDM). The electrodeposition current density and time were systematically investigated to uncover influencing factors of the growth process of CeO₂ nanostructures on the copper foam. The as-fabricated superhydrophobic foams could not only be used to efficiently separate oil/water mixtures with a separation efficiency greater than 97.4% but also presented robustness and high stability against 3.5 wt % NaCl solution and 600-grit sandpaper abrasion. Furthermore, the as-prepared sample still maintains a high separation efficiency at circa 97.5% after more than 25 times of recovery for kerosene/water mixture separation. In addition, the as-prepared three-dimensional cassette structure made of superhydrophobic copper foam could float freely on the water surface for fast in situ collection of oil from the water surface, indicating application potential in offshore oil spill treatment and cleanup.