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.