Photoelectrochemical Behavior of Self-Assembled Ag/Co Plasmonic Nanostructures Capped with TiO2.
The use of localized surface plasmon resonance induced by Ag nanostructures is a promising way for high-efficiency photoelectric conversion. In plasmonic photoelectric conversion devices, however, the chemical instability of Ag in ambient atmosphere and its immediate deterioration have been a critical issue. Here, we propose a Ag-Co nanostructure array embedded in a TiO2 matrix as a plasmonic resonator that ensures long-term stability. We also developed an electrochemical process to remove surface Co nanoclusters protecting fresh Ag from exposure to air. This enabled us to "unseal" Ag at the desired time. Furthermore, we confirmed photoelectric conversion using Ag-Co-TiO2 nanocomposite films in contact with solution; the photoelectric conversion was substantially enhanced by the plasmon resonance of the Ag nanorods. The Ag nanostructures sealed in a TiO2 matrix are expected to be used in other application fields, such as catalytisis and sensing, in which a fresh Ag surface is needed.
†Department of Chemistry, School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
Anri
A
Watanabe
§Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan.
Yuki
Y
Kotake
§Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan.
Yoshiomi
Y
Kamata
†Department of Chemistry, School of Science, The University of Tokyo, Tokyo 113-0033, Japan.|‡JST-CREST, Tokyo 113-0033, Japan.
Akira
A
Chikamatsu
§Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan.
Kosei
K
Ueno
§Research Institute for Electronic Science, Hokkaido University, Sapporo 001-0021, Japan.
Hiroaki
H
Misawa
†Department of Chemistry, School of Science, The University of Tokyo, Tokyo 113-0033, Japan.|‡JST-CREST, Tokyo 113-0033, Japan.
Tetsuya
T
Hasegawa
electrochemistry; nanocomposite; nanorod; photochemistry; pulsed laser deposition