Open AccessLuminescent Au6 and Au8 nanoclusters from ligand induced etching of Au nanoparticles
Author(s) -
Dipankar Bain,
Subarna Maity,
Tanay Debnath,
Abhijit K. Das,
Amitava Patra
Publication year - 2019
Publication title -
materials research express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.383
H-Index - 35
ISSN - 2053-1591
DOI - 10.1088/2053-1591/ab5c8b
Subject(s) - nanoclusters , luminescence , excited state , materials science , photoluminescence , nanoparticle , quantum yield , photochemistry , band gap , ligand (biochemistry) , analytical chemistry (journal) , nanotechnology , fluorescence , chemistry , optoelectronics , atomic physics , optics , organic chemistry , physics , biochemistry , receptor
Metal nanoclusters (NCs) with atomic precision are receiving significant attention because of their widespread applications in the field of energy-related materials, sensing and biomedicine. In this work, luminescent Au nanoclusters (NCs) are synthesized from Au nanoparticles (NPs) by core-etching process in presence of excess glutathione (GSH) ligand. Electrospray ionization (ESI) mass spectrometric study suggests the formation of polydisperse Au 6 and Au 8 NCs at elevated temperature (70 °C). The HOMO-LUMO band gap of Au 6 and Au 8 clusters are calculated from optimized structure. The photoluminescence maximum of as-prepared Au NCs is observed at 421 nm after excitation at 340 nm with 4.20% quantum yield (QY). Lifetime of the NCs is found to be 0.57 ns in excited state, which arises because of electronic transitions from low-lying d-bands to excited state sp bands of core-state only. Moreover the luminescence intensity of as-prepared Au NCs is found to be very stable both in acidic and basic medium. The synthesis of luminescent Au NCs from non-luminescent plasmonic Au NPs is beneficial for various applications such as sensing, biomedicine, and light emitting devices.