Design and preparation of efficient, stable and superhydrophobic copper foam membrane for selective oil absorption and consecutive oil–water separation

Abstract

It is extremely important and challenging to develop an effective device for the continuous separation and recovery of large-scale oil–water mixtures due to their contribution to ecological remediation and contamination control. In this work, a superhydrophobic copper foam with high oil–water separation efficiency was successfully fabricated, which could serve both as oil absorption material and oil–water separation membrane, by in situ self-sacrificial template method combining the subsequent steaming modification. The obtained characterization results present that copper foam possesses large pore structure, micro-/nanoscale two-tier surface roughness, high water contact angle (153.6°), and low sliding angle (4.5°). Experimental results show that as-prepared copper foam could not only rapidly absorb residual oil either on the water surface or underwater, but also separate a series of oils from water, like carbon tetrachloride, trichloromethane, methylbenzene, pump oil and diesel. Furthermore, the separation efficiencies of copper foam on trichloromethane-water and diesel-water mixture were maintained above 96.9% and 90.8% after 10 cycles, respectively. Additionally, as-prepared copper foam exhibits excellent corrosion resistant ability and superior hydrophobic stability. The facile, low-cost and controllable strategy presented herein has a bright future in oil–water separation, and also can be further expanded to prepare various anti-corrosion, self-cleaning and water-proof sport materials.