Shedding Light on the Nature of Photoinduced States Formed in a Hydrogen-Generating Supramolecular RuPt Photocatalyst by Ultrafast Spectroscopy

Summary, in English

Photoinduced electronic and structural changes of a hydrogen-generating supramolecular RuPt photocatalyst are studied by a combination of time-resolved photoluminescence, optical transient absorption, and X-ray absorption spectroscopy. This work uses the element specificity of X-ray techniques to focus on the interplay between the photophysical and -chemical processes and the associated time scales at the catalytic Pt moiety. We observe very fast (<30 ps) photoreduction of the Pt catalytic site, followed by an ∼600 ps step into a strongly oxidized Pt center. The latter process is likely induced by oxidative addition of reactive iodine species. The oxidized Pt species is long-lived and fully recovers to the original ground state complex on a >10 μs time scale. However, the photosensitizing Ru moiety is fully restored on a much shorter ∼300 ns time scale. This reaction scheme implies that we may withdraw two electrons from a catalyst that is activated by a single photon.

• Author: Annemarie Huijser; Qing Pan; David Van Duinen; Mads G. Laursen; Amal El Nahhas; Pavel Chabera; Leon Freitag; Leticia González; Qingyu Kong; Xiaoyi Zhang; Kristoffer Haldrup; Wesley R. Browne; Grigory Smolentsev; Jens Uhlig
• Department/s: Chemical Physics
• Publishing year: 2018-07-27
• Language: English
• Pages: 6396-6406
• Publication/Series: Journal of Physical Chemistry A
• Volume: 122
• Issue: 31
• Links: http://dx.doi.org/10.1021/acs.jpca.8b00916
• Document type: Journal article
• Publisher: The American Chemical Society (ACS)
• Topic: Organic Chemistry; Atom and Molecular Physics and Optics
• Status: Published
• ISBN/ISSN/Other: ISSN: 1089-5639