Silver-decorated titanium dioxide nanotube arrays with improved photocatalytic activity for visible light irradiation

摘要

Silver-decorated titanium dioxide (Ag/TiO_2) nanotube (NT) arrays were successfully prepared using a two-step synthesis route comprised of an anodic oxidation procedure followed by photochemical reduction using ultraviolet irradiation. The resulting Ag/TiO_2 NT arrays were characterized using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and UV-vis diffusion reflectance spectrometry. The characterization results indicated that the silver decoration significantly enhanced the light absorption capability of the TiO_2 NT arrays in the visible spectral range. The visible light photocatalytic activity of the subject NT arrays was investigated. The experimental results showed the photocatalytic activity of silver-decorated titanium dioxide Ag/TiO_2 NT arrays to be dependent on the size of the silver particles. The improved visible light absorption can be attributed to plasmonic effects induced by particle size phenomenon. The Ag/TiO_2 NT arrays exhibit promising application for photocatalytic degradation of dye solutions and pollutants in water using visible irradiation.