Photoelectrochemical Control of Silver Nanoparticle Orientation on the Basis of Plasmon Resonance

Orientation of anisotropic Ag nanoparticles (NPs) on a polycrystalline TiO2 film was controlled by photoelectrochemical means on the basis of localized surface plasmon resonance. Simultaneous irradiation of the TiO2 film in a AgNO3 solution with UV and polarized far red light resulted in deposition of rod-like Ag NPs oriented perpendicularly to the polarization angle. UV light induces photocatalytic growth of Ag NPs by excitation of TiO2, and polarized far red light limits the growth in the direction parallel to the polarization angle.