Interfacial design of gold/silver core-shell nanostars for plasmon-enhanced photocatalytic coupling of 4-aminothiophenol

Kaur, Gagandeep; Tanwar, Swati; Kaur, Vishaldeep; Biswas, Rathindranath; Saini, Sangeeta; Haldar, Krishna Kanta; Sen, Tapasi

Interfacial design of gold/silver core-shell nanostars for plasmon-enhanced photocatalytic coupling of 4-aminothiophenol

Date

2021-10-02T00:00:00

Authors

Kaur, Gagandeep

Tanwar, Swati

Kaur, Vishaldeep

Biswas, Rathindranath

Saini, Sangeeta

Haldar, Krishna Kanta

Sen, Tapasi

Publisher

Royal Society of Chemistry

Abstract

Chemical reactions under mild conditions mediated by localized surface plasmon resonance (LSPR) of metals have emerged as a functional research field. In the present study, we report an interfacial designing procedure for the fabrication of a class of bimetallic hybrid nanomaterials as a profoundly active photocatalyst for the conversion of para-aminothiophenol (PATP) into 4,4?-dimercaptoazobenzene. For this purpose, core-shell nanostars composed of gold (core) and silver (shell) (Au/Ag NSs) were utilized as both surface-enhanced Raman scattering substrate and plasmon driven catalyst under 532 nm laser excitation. Au/Ag NSs with sharp tips display excellent surface-enhanced Raman scattering (SERS) efficiency of PATP. Employing the SERS study, it has been found that PATP rapidly converts into its dimerized product DMAB within few seconds by surface photochemical reaction in the Au-Ag heterojunction of core-shell nanostars. Au/Ag NSs with multiple sharp tips exhibit intense LSPR and highly strong electric fields are created at the tips, which enables the generation of hot electrons responsible for the rapid conversion reaction. Such well-designed interfacial bimetallic nanostars could have potential applications in surface enhanced spectroscopy, biosensing, and photoinduced surface catalysis. This journal is � The Royal Society of Chemistry.

Keywords

Binary alloys, Design, Electric fields, Gold, Heterojunctions, Hot electrons, Laser excitation, Nanorods, Raman scattering, Silver alloys, Substrates, Surface plasmon resonance, Surface reactions, Surface scattering, Bimetallics, Core shell, Enhanced Raman scattering, Interfacial design, Localized surface plasmon resonance, Nanostar, Photo-catalytic, Sharp tip, Silver cores, Surface enhanced Raman, Shells (structures)