Evidence for Conduction Band-Mediated Two-Electron Reduction of a TiO2-Bound Catalyst Triggered by Visible Light Excitation of Co-Adsorbed Organic Dyes
Artikel i vetenskaplig tidskrift, 2018

Here, we report direct spectroscopic evidence of a visible light-induced two-electron-transfer reaction to a molecular model catalyst, facilitated by conduction band mediation. Using a simple, yet remarkably reproducible, co-sensitization approach, we anchored dyes and catalysts to mesoporous TiO2 thin films, at dye/catalyst ratios of 30:1, 15:1, and 8:1. The distinct optical spectroscopic signatures of different redox states of the catalyst used, Co-protoporphyrin IX, allows for transient absorption detection of intermediate and final photoproducts in the photoexcited co-sensitized dye-TiO2-catalyst assemblies. We show that by tuning the dye/catalyst ratios, control over whether photoexcitation results in one or two electrons being transferred to the catalyst is achieved. The two-electron-transfer process is favored by a large excess of photosensitizer compared to catalyst.

Författare

Valeria Saavedra

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Fysikalisk kemi

Elin Sundin

Chalmers, Kemi och kemiteknik, Kemi och biokemi, Fysikalisk kemi

Maria Abrahamsson

Chalmers, Kemi och kemiteknik, Kemi och biokemi

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 122 45

Ämneskategorier

Atom- och molekylfysik och optik

Annan kemi

Den kondenserade materiens fysik

DOI

10.1021/acs.jpcc.8b07669

Mer information

Senast uppdaterat

2018-12-10