Effect of Light Irradiation on Hot Electron-Mediated Photoreduction of Silver Ions on Single Gold Nanorods without a Reducing Agent
Jaeran Lee, Ji Won Ha
Abstract
This study investigated the hot electron-mediated photoreduction of silver (Ag) ions on gold nanorods (AuNRs) exposed to a silver nitrate (AgNO 3 ) solution under white light irradiation without a reducing agent and the effect of white light irradiation on the structural and spectral changes in single AuNRs. The hot electron-mediated Ag deposition was confirmed to occur upon white light irradiation, producing AuNRs@Ag (core@shell) structures. No noticeable changes in the size of AuNRs@Ag in the transverse and longitudinal directions were observed as compared with bare AuNRs. The Ag deposition on AuNRs led to an increased scattering intensity as well as a blue shift and line width broadening of the localized surface plasmon resonance (LSPR) peak. Additionally, we investigated the effect of using different light-on/off cycle conditions on the LSPR properties during the formation of the Ag layer on AuNRs. Moreover, increasing the AgNO 3 concentration resulted in more pronounced LSPR peak shifts. Overall, fundamental information on the effect of the light irradiation method used for the hot electron-mediated Ag deposition without a reductant on the structural and LSPR changes is provided at the single-particle level.