Membrane surface modification with TiO2-graphene oxide for enhanced photocatalytic performance

Taking advantage of the unique property of graphene oxide (GO) nanomaterials in expanding the light response range of TiO2, we modified the surface of water filtration membranes with TiO2-GO to enhance their photocatalytic activities under both UV and sunlight irradiations. A layer-by-layer approach was employed to sequentially deposit TiO2 nanoparticles and GO nanosheets on a polysullone base membrane, with GO partially reduced via ethanol/UV post-treatment. The grafting of TiO2-GO on the membrane surface was confirmed through the analysis of QCM-D measurements and SEM images. We then studied the photocatalytic properties of the surface-modified membranes in both batch and filtration experiments using methylene blue (MB) as a representative organic contaminant. Compared with polysulfone membranes surface-modified with TiO2 and GO, respectively, the TiO2-GO membrane exhibited significantly improved MB photodegradation kinetics under UV (about 60-80% faster) and sunlight (3-4 Limes faster). Besides, the membrane flux increased as a result of the photo-enhanced hydrophilicity and contaminant degradation. Therefore, surface modification by TiO2-GO grafting provides a very promising route to the fabrication of high-performance photocatalytic membranes for sustainable water treatment. (C) 2014 Elsevier B.V. All rights reserved