Photochemical deposition of platinum on titanium dioxide–tungsten trioxide nanocomposites: an efficient photocatalyst under visible light irradiation

Abstract

Highly ordered titanium dioxide–tungsten trioxide nanotubular composites (TiO2–WO3) were fabricated on titanium sheets by electrochemical anodizing. Platinum nanoparticles have been successfully deposited onto TiO2–WO3 nanotubes by UV light photoreduction method. In this work, X-ray diffraction, field emission scanning electron microscope, ultraviolet–visible spectroscopy and energy dispersive X-ray spectrometer methods were adopted to characterize the samples. The degradation of methylene blue (MB) was used as a model reaction to evaluate the photocatalytic activity of the obtained samples. After irradiated under visible light for 60 min, the degradation rate of MB solution on unmodified TiO2–WO3 and Pt/TiO2–WO3 reached 77 and 93 %, respectively. Under the same condition, no obvious photodegradation of MB was found for bare TiO2 (T). Kinetic research showed that photodegradation process followed the first-order reaction; the apparent reaction rate constant of Pt/TiO2–WO3-1 was 4.56 × 10−2 min−1 which is approximately 1.75 times higher than that on the unmodified TiO2–WO3. This work provides an insight into designing and synthesizing new TiO2–WO3 nanotubes based hybrid materials for effective visible light-activated photocatalysis.