UV–vis light induced photocatalytic activity of TiO2/graphene oxide nanocomposite coatings

Abstract Titanium dioxide (TiO 2 ) and TiO 2 – graphene oxide (GO) composite layers were deposited by spin coating technique onto SiO 2 quartz substrates. TiO 2 NPs and GO platelets were used as base materials for the preparation of the starting water/acetone dispersions. Polystyrene (PS) buffer layers were deposited by drop-cast method onto the substrates surface to ensure the adherence of the pure TiO 2 /PS and TiO 2 -GO/PS composite layer. The surface morphology and physico-chemical properties of the layers have been determined and correlated with their photocatalytic properties. It was found that GO oxygen functional groups are reduced by the presence of TiO 2 NPs in the composite materials. Photodegradation activity under UV–visible light irradiation was studied by measuring the concentration changes in time of organic methylene blue dye in aqueous solutions as well as the chemical oxygen demand for real wastewater samples. The obtained results revealed that the photocatalytic properties of the spin coated composites are determined by the graphene oxide concentration. The effect of the spontaneous reduction of GO in the presence of TiO 2 NPs on the photocatalytic activity of the TiO 2 -GO/PS composites is discussed in detail.