Preparation of Gold/Silver/Titania Trilayered Nanorods and Their Photocatalytic Activities

摘要

Gold/silver/titania trilayered nanorods have been prepared by the successive deposition of silver and titania layers on gold nanorod cores, and their photocatalytic activities were investigated under visible-light illumination (λ > 420 nm). The photocatalytic activity of the trilayered nanorods in the oxidation of 2-propanol depends on both the Au/Ag composition and the thickness of the TiO_2 shell. It increases with increasing Ag content up to Au/Ag = 1:5 (molar ratio) and then decreases with further increasing Ag content. The photocatalytic activity also increases with increasing TiO_2 shell thickness up to 10 nm and then decreases with further increases in the shell thickness. These effects were explained by electrontransfer and energy-transfer mechanisms.