Size-Selective Formation of Hexagonal Silver Nanoprisms in Silver Citrate Solution by Monochromatic-Visible-Light Irradiation

Autor: Satoru Ohmura, Yoshitaka Maeda, Hisanori Tanimoto
Rok vydání: 2012
Předmět:
Zdroj: The Journal of Physical Chemistry C. 116:15819-15825
ISSN: 1932-7455
1932-7447
DOI: 10.1021/jp304504c
Popis: Silver citrate solution was irradiated by monochromatic light from light-emitting diodes (LEDs). Under visible-light irradiation, a characteristic peak (Abshex) was observed in the absorption spectrum above a certain value of fluence (Φthres). The formation of hexagonal silver nanoprisms was confirmed by transmission electron microscopy observations; the size of these hexagons in the in-plane direction decreased with increasing ELED (nominal peak energy). The formation process was investigated from the fluence evolution of Abshex, which was due to the localized surface plasmon resonance of the nanoprisms. With decreasing ELED, Φthres showed an exponential increase and the growth rate of Abshex beyond Φthres (ΔAbshex/ΔΦ*, Φ* = Φ – Φthres) showed a linear decrease. The ΔAbshex/ΔΦ* vs ELED data indicated that ΔAbshex/ΔΦ* became zero at ELED = 1.9 eV. Generally, the peak energy of Abshex expected at Φ* = 0 was close to ELED. These results indicated that embryos were formed by visible-light irradiation below Φ...
Databáze: OpenAIRE