Simple preparation of superhydrophobic copper foam for efficient oil-water separation

It is essential to develop efficient, durable, and cost-effective oil-water separation technologies due to the increase in oily wastewater discharges. In this work, superhydrophobic copper foam with high oil-water separation was successfully prepared. Construction of Cu(OH)2 and CuS on the surface of copper foam increased the roughness. Then the superhydrophobic copper foam with a WCA of 153.58° and a rolling angle of 3° was successfully prepared by stearic acid (SA) modification. The fabricated samples were then characterized using SEM、EDS、XPS, and contact angle measurement. Superhydrophobic copper foam exhibited an excellent ability to separate different various oil-water mixtures with a separation efficiency of more than 99.5 %. Even after 40 cycles, superhydrophobic copper foam maintained an impressive separation efficiency of over 98 %. It also exhibited excellent separation efficiency for various water-in-oil emulsions. Due to the advantages of simple preparation method, mechanical stability, corrosion resistance, efficient oil-water separation capability and self-cleaning, the superhydrophobic copper foam can be widely applied in practical applications for oily wastewater treatment.