Tunable Optical Properties of Ag–TiO2 Nanorod Composites Based on Interparticle Plasmon Coupling

The metal–semiconductor composites with unique optical properties are highly desirable. Here we report that Ag–TiO2 nanorod composites with two distinctive absorption peaks exhibit tunable plasmon coupling behaviors. The intensity of the long-wave absorption could be enhanced by modifying the geometry of TiO2 particles, while such absorption is due to the plasmon coupling between the Ag particles. The long-wave absorption bands can be tuned by varying the reaction time and changing the amount of silver acetate. Furthermore, the Ag–TiO2 composites were also prepared by photochemical reduction method which confirmed the previous properties. These results may help to design metal–semiconductor systems with desirable optical properties.