Au@CdSe heteroepitaxial nanorods: An example of metal nanorods fully covered by a semiconductor shell with strong photo-induced interfacial charge transfer effects

Suh-Ciuan Lim; Wen-Fu Lo; Po-Yuan Yang; Shu-Chen Lu; Anneli Joplin; Stephan Link; Wei-Shun Chang; Hsing-Yu Tuan

doi:10.1016/j.jcis.2018.07.080

Au@CdSe heteroepitaxial nanorods: An example of metal nanorods fully covered by a semiconductor shell with strong photo-induced interfacial charge transfer effects

J Colloid Interface Sci. 2018 Dec 15:532:143-152. doi: 10.1016/j.jcis.2018.07.080. Epub 2018 Jul 20.

Authors

Suh-Ciuan Lim¹, Wen-Fu Lo¹, Po-Yuan Yang¹, Shu-Chen Lu¹, Anneli Joplin², Stephan Link², Wei-Shun Chang³, Hsing-Yu Tuan⁴

Affiliations

¹ Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan, ROC.
² Department of Chemistry, Rice University, 6100 Main Street, Houston, TX 77005, United States.
³ Department of Chemistry, Rice University, 6100 Main Street, Houston, TX 77005, United States; Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, 285 Old Westport Rd, North Dartmouth, Massachusetts 02747, United States. Electronic address: wchang2@umassd.edu.
⁴ Department of Chemical Engineering, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan, ROC. Electronic address: hytuan@che.nthu.edu.tw.

PMID: 30077828
DOI: 10.1016/j.jcis.2018.07.080

Abstract

Synthesis of metal@semiconductor heteroepitaxial nanorods fully covered by a semiconductor shell remains challenging due to the large lattice mismatch between the two components. Here, we prepared Au@CdSe heteroepitaxial nanorods by employing pre-growth of Ag₂Se as an intermediate layer that favored the formation of a complete CdSe shell via a cation-exchange process. The optical properties of these hybrid nanostructures can be tailored by changing the shell thickness with thicker shells resulting in a redshift of the longitudinal surface plasmon resonance. The resonance energy, intensity, and linewidth of the longitudinal surface plasmon resonance were measured by single-particle dark-field scattering spectroscopy, confirming significant electron transfer from the Au nanorod to the CdSe shell. In addition, we also studied the dependence of the catalytic reactivity on shell thickness in photocatalysis of methylene blue under UV illumination. These studies revealed that a thinner shell thickness resulted in higher photocatalytic activity.

Keywords: Cation-exchange process; Heteroepitaxial nanorods; Metal@semiconductor; Photocatalytic activity; Single-particle dark-field scattering; Surface plasmon resonance.