Facile fabrication of superhydrophobic, superoleophilic photocatalytic membrane for efficient oil-water separation and removal of hazardous organic pollutants

In this work, the fabrication and characterization of a dual-purpose membrane is reported: (i) oil-water separation with high efficiency, and (ii) effective and rapid photocatalytic degradation of hazardous environmental pollutants. Nanoparticles of a rare-earth oxide, cerium (IV) oxide, synthesized by a simple co-precipitation technique, were spray-coated onto stainless steel membranes to obtain a uniform coating with superwetting characteristics. The as-synthesized cerium (IV) oxide nanoparticles and its spray-coated stainless steel membrane were characterized by advanced analytical techniques. X-ray diffraction, selected area electron diffraction, and electron microscopy results of the cerium oxide particles showed a high degree of crystallinity and uniform particle size of similar to 50 nm. Elemental surface analysis using X-ray photoelectron spectroscopy showed the characteristic peaks for Ce4+, thereby confirming the presence of cerium oxide nanoparticles. Contact angle measurements showed the coated membranes to be superhydrophobic (similar to 150 degrees) and superoleophilic (similar to 0 degrees). When used in a simple laboratory setup, the membranes were able to separate oil and water with a high efficiency (similar to 99%). Furthermore, the coated membrane showed enhanced photocatalytic activity under UV light irradiation resulting in the rapid degradation of organic persistent pollutants like MB dye in water. To summarize, this work presents an innovative approach in the application of multifunctional membranes for effective water treatment. (C) 2018 Elsevier Ltd. All rights reserved.