Preparation and characterization of Pt/Pd-modified titanium dioxide nanoparticles for visible light irradiation

Series of Pt/Pd-TiO2 photocatalysts were obtained using the sol-gel method. The Pt/Pd-TiO2 nanocomposites showed significant visible light photoactivity. X-ray diffraction, STEM microscopy, UV-vis spectroscopy and BET characterization allowed to conclude that the photocatalysts at the best performance had the anatase structure, 91 m(2)/g specific surface area, Pt/Pd alloy structure and 1-4 nm particle size. The photocatalytic activity was evaluated by measuring the decomposition rate of phenol in 0.21 mM aqueous solution under visible light irradiation (lambda > 420 nm). The effect of platinum precursor, crystallite size of TiO2 on photocatalytic activity of the Pt/Pd-TiO2 nanocomposites was investigated. The best photocatalytic activity was observed for the sample Pt/Pd-TiO2 modified with 0.5 mol% of platinum and 0.5 mol% of palladium. The average degradation rate of 6.84 mu mol dm(-3) min(-1) for phenol was about 19 times greater than for pure TiO2 obtained using the same preparation procedure. (c) 2013 Elsevier B.V. All rights reserved.