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Active repair of a dinuclear photocatalyst for visible-light-driven hydrogen production

Abstract

The molecular apparatus behind biological photosynthesis retains its long-term functionality through enzymatic repair. However, bioinspired molecular devices designed for artificial photosynthesis, consisting of a photocentre, a bridging ligand and a catalytic centre, can become unstable and break down when their individual modules are structurally compromised, halting their overall functionality and operation. Here we report the active repair of such an artificial photosynthetic molecular device, leading to complete recovery of catalytic activity. We have identified the hydrogenation of the bridging ligand, which inhibits the light-driven electron transfer between the photocentre and catalytic centre, as the deactivation mechanism. As a means of repair, we used the light-driven generation of singlet oxygen, catalysed by the photocentre, to enable the oxidative dehydrogenation of the bridging unit, which leads to the restoration of photocatalytic hydrogen formation.

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Fig. 1: Visible-light-driven hydrogen production with a PMD.
Fig. 2: UV–vis absorption spectra of the catalytic solution at different irradiation times.
Fig. 3: UV–vis and ultrafast transient absorption spectra of the catalytic solution at different irradiation times.
Fig. 4: UV–vis absorption spectra for the dehydrogenation of the deactivated photocatalyst Ru(tpphzH2)PtI2 by singlet oxygen.
Fig. 5: Repetitive active repair of the Ru(bptz)PtCl2 photocatalyst.

Data availability

Source data are provided with this paper and can also be found via Zenodo (https://doi.org/10.5281/zenodo.5565021). All other data supporting the findings of this study are available within the paper and its Supplementary Information files.

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Acknowledgements

We thank the German Science Foundation for funding via the TRR 234 CataLight (project number 364549901; project A1, C.M., B.D.-I. and S.R.; project B4, M.W.; project C5, P.S., S.K. and S.G), the Fonds der Chemischen Industrie (Kekulé-Stipendium, C.M.) and the Studienstiftung des Deutschen Volkes (PhD scholarship, B.B.). We acknowledge the developers of the KiMoPack software employed for global lifetime analysis of the time-resolved spectra. All calculations were performed at the Universitätsrechenzentrum (Friedrich Schiller University Jena, P.S., S.K. and S.G.). The funding organizations had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript.

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Authors and Affiliations

Authors

Contributions

M.G.P., E.T.E.K. and D.C. performed the catalysis experiments, C.M. performed the steady-state and time-dependent in situ spectroscopic studies, and M.S. and M.W. synthesized and investigated the hydrogenated photocatalyst. M.G.P., A.K.M., B.B., S.F., J.H., D.C., F.L., G.S.H. and S.R. developed the active repair strategies. P.S., S.K. and S.G. conducted the quantum chemical simulations. M.G.P, C.M., L.P., G.S.H., J.G.V., A.K.M., B.D.-I. and S.R. wrote the manuscript with help from all the other authors.

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Correspondence to Benjamin Dietzek-Ivanšić or Sven Rau.

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Nature Chemistry thanks Ken Sakai, Claudia Turro and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–27, Tables 1–4, Discussion and Experimental Details.

Source data

Source Data Fig. 1

Hydrogen turnover numbers and chemical structures.

Source Data Fig. 2

In situ absorption data and chemical structures.

Source Data Fig. 3

In situ absorption and ultrafast transient absorption data, hydrogen turnover numbers (mean, s.d., n = 3) and peak area ratios.

Source Data Fig. 4

Absorption data.

Source Data Fig. 5

Hydrogen turnover numbers and chemical structures.

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Pfeffer, M.G., Müller, C., Kastl, E.T.E. et al. Active repair of a dinuclear photocatalyst for visible-light-driven hydrogen production. Nat. Chem. 14, 500–506 (2022). https://doi.org/10.1038/s41557-021-00860-6

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