Strong localized surface plasmon resonance effects of Ag/TiO2 core-shell nanowire arrays in UV and visible light for photocatalytic activity

Abstract

Periodic arrays of silver/titanium dioxide (Ag/TiO2) open core-shell nanowires have been investigated as enhanced plasmonic photocatalytic structures. Sequential top-down nanofabrication processes based on nanoimprinting, oblique angle evaporation, and selective electrodeposition were employed for the fabrication of various TiO2-shelled Ag nanowire arrays. Numerical simulation proves that the periodic array of Ag/TiO2 core-shell nanowire structures enables strong localized surface plasmon resonance (LSPR), which improves the electron generation and photocatalytic activities of the TiO2 shell. Enhanced photocatalytic performance was confirmed by the decomposition of methylene blue solution. Furthermore, the film composed of a Ag/TiO2 core-shell nanowire array shows photocatalytic reproducibility in the UV and visible light regions and mechanical robustness due to the periodic grating-like metal nanostructures. Our method allows reliable, controllable, and facile fabrication of large-scale plasmonic photocatalytic nanostructured films on various substrates such as glass, polymer, etc.