1. Real-space observation of far- and near-field-induced photolysis of molecular oxygen on an Ag(110) surface by visible light
- Author
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Kei Ikeda, Takashi Kumagai, Yoshihito Shiota, Kazunari Yoshizawa, and Chenfang Lin
- Subjects
Materials science ,010304 chemical physics ,Photodissociation ,General Physics and Astronomy ,chemistry.chemical_element ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Oxygen ,Dissociation (chemistry) ,0104 chemical sciences ,law.invention ,chemistry ,law ,0103 physical sciences ,Molecule ,Density functional theory ,Astrophysics::Earth and Planetary Astrophysics ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Scanning tunneling microscope ,Excitation ,Visible spectrum - Abstract
Dissociation of molecular oxygen is an important elementary process in heterogeneous catalysis. Here, we report on a real-space observation of oxygen photolysis on the Ag(110) surface at 78 K by far- and near-field excitation in the ultraviolet–near-infrared range using a low-temperature scanning tunneling microscope (STM) combined with wavelength-tunable laser excitation. The photolysis of isolated oxygen molecules on the surface occurs even by visible light with the cross section of ∼10−19 cm2. Time-dependent density functional theory calculations reveal optical absorption of the hybridized O2–Ag(110) complex in the visible and the near-infrared range which is associated with the oxygen photolysis. We suggest that the photolysis mechanism involves a direct charge transfer process. We also demonstrate that the photolysis can be largely enhanced in plasmonic STM junctions, and the cross section is estimated to be ∼10−17 cm-2in the visible and the near-infrared range, which appears to be an interesting feature of plasmon-induced reactions from the perspective of photochemical conversion with the aid of solar energy.
- Published
- 2019