Efficient oil/water separation by superhydrophobic CuxS coated on copper mesh

Abstract

The marine petroleum exploitation as well as the oil transport have caused ecological problems all around the world. Spilled oil is a major threat to the environment and ecosystem of sea. As such, purification of water from organic pollutants and oils is highly imperative. For this purpose, a superhydrophobic and superoleophilic CuxS/Cu mesh (x = 1 and 2) has been prepared. CuS and Cu2S micro-particles were grown onto copper mesh by hydrothermal treatment. After further modification using stearic acid (SA), the CuxS/Cu mesh with superhydrophobic characteristics was obtained. Superhydrophobicity of the obtained sample is attributed to the combination effects of rough CuxS microstructures and coating with low surface energy SA molecules. The prepared sample displays a water contact angle of 160 ± 1° and was characterized by SEM, AFM, EDS, and XPS techniques. The developed superhydrophobic copper mesh was transformed to a miniature container, which can float freely on water surface and selectively absorbs different kinds of oils on water surface while repels water completely. Furthermore, the superhydrophobic miniature container could be reused several times for the oil-water separation without any apparent decrease of its separation capability. Thus the prepared superhydrophobic/superoleophilic mesh holds promise for various applications in the industrial field of oil-water separation.