Photogenerated
Charge Carriers and Reactive Oxygen
Species in ZnO/Au Hybrid Nanostructures with Enhanced Photocatalytic
and Antibacterial Activity
Weiwei He
Hyun-Kyung Kim
Wayne G. Wamer
David Melka
John H. Callahan
Jun-Jie Yin
10.1021/ja410800y.s001
https://acs.figshare.com/articles/journal_contribution/Photogenerated_Charge_Carriers_and_Reactive_Oxygen_Species_in_ZnO_Au_Hybrid_Nanostructures_with_Enhanced_Photocatalytic_and_Antibacterial_Activity/2332204
Semiconductor
nanostructures with photocatalytic activity have
the potential for many applications including remediation of environmental
pollutants and use in antibacterial products. An effective way for
promoting photocatalytic activity is depositing noble metal nanoparticles
(NPs) on a semiconductor. In this paper, we demonstrated the successful
deposition of Au NPs, having sizes smaller than 3 nm, onto ZnO NPs.
ZnO/Au hybrid nanostructures having different molar ratios of Au to
ZnO were synthesized. It was found that Au nanocomponents even at
a very low Au/ZnO molar ratio of 0.2% can greatly enhance the photocatalytic
and antibacterial activity of ZnO. Electron spin resonance spectroscopy
with spin trapping and spin labeling was used to investigate the enhancing
effect of Au NPs on the generation of reactive oxygen species and
photoinduced charge carriers. Deposition of Au NPs onto ZnO resulted
in a dramatic increase in light-induced generation of hydroxyl radical,
superoxide and singlet oxygen, and production of holes and electrons.
The enhancing effect of Au was dependent on the molar ratio of Au
present in the ZnO/Au nanostructures. Consistent with these results
from ESR measurements, ZnO/Au nanostructures also exhibited enhanced
photocatalytic and antibacterial activity. These results unveiled
the enhanced mechanism of Au on ZnO and these materials have great
potential for use in water purification and antibacterial products.
2014-01-15 00:00:00
Antibacterial ActivitySemiconductor nanostructures
Photogenerated Charge Carriers
NP
photoinduced charge carriers
Reactive Oxygen Species
photocatalytic activity
ZnO
reactive oxygen species
ESR