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Title: High-Potential Porphyrins Supported on SnO 2 and TiO 2 Surfaces for Photoelectrochemical Applications

Here, we report CF 3-substituted porphyrins and evaluate their use as photosensitizers in water-splitting dye-sensitized photoelectrochemical cells (WS-DSPECs) by characterizing interfacial electron transfer on metal oxide surfaces. Furthermore, by using (CF 3) 2C 6H 3 instead of C 6F 5 substituents at the meso positions, we obtain the desired high potentials while avoiding the sensitivity of C 6F 5 substituents to nucleophilic substitution, a process that limits the types of synthetic reactions that can be used. Both the number of CF 3 groups and the central metal tune the ground and excited-state potentials. A pair of porphyrins bearing carboxylic acids as anchoring groups were deposited on SnO 2 and TiO 2 surfaces and the interfacial charge-injection and charge-recombination kinetics were characterized by using a combination of computational modeling, terahertz measurements, and transient absorption spectroscopy. We also found that both free-base and metallated porphyrins inject into SnO 2, and that recombination is slower for the latter case. Our findings demonstrate that (CF 3) 2C 6H 3-substituted porphyrins are promising photosensitizers for use in WS-DSPECs.
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  1. Yale Univ., New Haven, CT (United States). Dept. of Chemistry and Energy Sciences Inst.
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Physical Chemistry. C
Additional Journal Information:
Journal Volume: 120; Journal Issue: 51; Journal ID: ISSN 1932-7447
American Chemical Society
Research Org:
Yale Univ., New Haven, CT (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
14 SOLAR ENERGY; interfacial electron transfer; photosensitizers; transient absorption; terahertz spectroscopy; trifluoromethylphenyl; density functional theory
OSTI Identifier: