Bi- and Uniaxially Oriented Growth and Plasmon Resonance Properties of Anisotropic Ag Nanoparticles on Single Crystalline TiO2 Surfaces

Anisotropic Ag nanoparticles were grown epitaxially on UV-irradiated rutile TiO2(100) and (110) single crystals in an aqueous AgNO3 solution by photoelectrochemical reduction of Ag+. Under different conditions (0.1-10 mW cm(-2) UV irradiation for 1 min-21 h in the presence or absence of ethanol or acetaldehyde or both) and on different substrates, biaxially and uniaxially orientated crystalline nanorods, uniaxially oriented triangular nanoplates (i.e., so-called nanoprisms), or square pyramids were grown preferentially, without need for a masking layer or alignment step. This represents a new route for the fabrication of polarized, visible-near-infrared sensitizing thin layers on TiO2.