Ultrafast Electron Transfer Between Dye and Catalyst on a Mesoporous NiO Surface

作者：Brown Allison M; Antila Liisa J; Mirmohades Mohammad; Pullen Sonja; Ott Sascha; Hammarstrom Leif

来源：Journal of the American Chemical Society, 2016, 138(26): 8060-8063.

DOI：10.1021/jacs.6b03889

The combination of molecular dyes and catalysts with semiconductors into dye-sensitized solar fuel devices (DSSFDs) requires control of efficient interfacial and surface charge transfer between the components. The present study reports on the light-induced electron transfer processes of p-type NiO films cosensitized with coumarin C343 and a bioinspired proton reduction catalyst, [FeFe](mcbdt)(CO)(6) (mcbdt = 3-carboxybenzene-1,2-dithiolate). By transient optical spectroscopy we find that ultrafast interfacial electron transfer (tau approximate to 200 fs) from NiO to the excited C343 ("hole injection") is followed by rapid (t(1/2) approximate to 10 ps) and efficient surface electron transfer from C343 to the coadsorbed [FeFe] (mcbdt)(CO)(6). The reduced catalyst has a clear spectroscopic signature that persists for several tens of microseconds, before charge recombination with NiO holes occurs. The demonstration of rapid surface electron transfer from dye to catalyst on NiO, and the relatively long lifetime of the resulting charge separated state, suggests the possibility to use these systems for photocathodes on. DSSFDs.

• 出版日期2016-7-6