The Synthesis And Kinetic Growth Of Anisotropic Silver Particles Loaded On Tio_2 Surface By Photoelectrochemical Reduction Method

摘要

Silver nanorods with average diameters of 120-230 nm and aspect ratio of 1.7-5.0 were deposited on the surface of TiO_2 films by photoelectrochemical reduction of Ag~+ to Ag under UV light. The composite films prepared on soda-lime glass substrates were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the TiO_2 film after UV irradiation in AgNO, solution is composed of anatase phase TiO_2 and metallic silver with face centered cubic structure. Other compounds cannot be found in the final films. The maximum deposition content of silver particles on the surface of TiO_2 film was obtained with the AgNO_3 concentration of 0.1 M. The kinetic growth rates of silver particles can be controlled by photocatalytic activity of TiO_2 films. The studies suggest that the growth rates of silver particles increase with the enhancement of photocatalytic activity of TiO_2 films. The maximum growth rate of silver particles loaded on TiO_2 films can be up to 0.353 nm min~(-1) among samples 1#, 2# and 3#, while the corresponding apparent rate constant of TiO_2 is 1.751 × 10~(-3) min~(-1).