Abstract
This study probes a series of linkers and anchoring groups for direct interfacial electron transfer (IET) from high-potential porphyrins into semiconductor surfaces. Eight different linker-anchor combinations of CF3-substituted, high-potential porphyrins were designed, synthesized, and characterized. Specifically, a series of four anchors was examined (carboxylate, hydroxamate, phosphonate, and silatrane), along with two different linkers (phenylene and benzanilidylene), which differ in terms of their electronic conjugation and overall length. The electrochemical and photophysical properties of the porphyrins were evaluated by steady-state and transient spectroscopies in solution and on mesoporous SnO2 substrates for use as dye photosensitizers in aqueous photoelectrochemical cells. IET dynamics were measured using time-resolved terahertz (TRTS) and transient absorption spectroscopies. From TRTS measurements, injection yields were determined relative to a commonly used phosphonated ruthenium(II) polypyridyl complex, which is reported to have near quantitative injection yield. We find that IET occurs through space rather than through the linkers, due to the tilted orientation of the adsorbed porphyrins in direct contact with the metal oxide surface. As a result, the anchoring groups have a less significant effect on IET dynamics than for adsorbates exhibiting through-linker injection. Experiments are supported by DFT calculations, including the analysis of different electron-injection pathways. Direct IET offers the advantage of the selection of anchoring groups based solely on chemical/photoelectrochemical stability and synthetic viability, irrespective of the electronic coupling of the anchoring group to the metal oxide surface.
| Original language | English |
|---|---|
| Pages (from-to) | 13529-13539 |
| Number of pages | 11 |
| Journal | Journal of Physical Chemistry C |
| Volume | 122 |
| Issue number | 25 |
| DOIs | |
| Publication status | Published - Jun 28 2018 |
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ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
Cite this
Direct Interfacial Electron Transfer from High-Potential Porphyrins into Semiconductor Surfaces : A Comparison of Linkers and Anchoring Groups. / Jiang, Jianbing; Spies, Jacob A.; Swierk, John R.; Matula, Adam J.; Regan, Kevin P.; Romano, Neyen; Brennan, Bradley J.; Crabtree, Robert H.; Batista, Victor S.; Schmuttenmaer, Charles A.; Brudvig, Gary W.
In: Journal of Physical Chemistry C, Vol. 122, No. 25, 28.06.2018, p. 13529-13539.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Direct Interfacial Electron Transfer from High-Potential Porphyrins into Semiconductor Surfaces
T2 - A Comparison of Linkers and Anchoring Groups
AU - Jiang, Jianbing
AU - Spies, Jacob A.
AU - Swierk, John R.
AU - Matula, Adam J.
AU - Regan, Kevin P.
AU - Romano, Neyen
AU - Brennan, Bradley J.
AU - Crabtree, Robert H.
AU - Batista, Victor S.
AU - Schmuttenmaer, Charles A.
AU - Brudvig, Gary W
PY - 2018/6/28
Y1 - 2018/6/28
N2 - This study probes a series of linkers and anchoring groups for direct interfacial electron transfer (IET) from high-potential porphyrins into semiconductor surfaces. Eight different linker-anchor combinations of CF3-substituted, high-potential porphyrins were designed, synthesized, and characterized. Specifically, a series of four anchors was examined (carboxylate, hydroxamate, phosphonate, and silatrane), along with two different linkers (phenylene and benzanilidylene), which differ in terms of their electronic conjugation and overall length. The electrochemical and photophysical properties of the porphyrins were evaluated by steady-state and transient spectroscopies in solution and on mesoporous SnO2 substrates for use as dye photosensitizers in aqueous photoelectrochemical cells. IET dynamics were measured using time-resolved terahertz (TRTS) and transient absorption spectroscopies. From TRTS measurements, injection yields were determined relative to a commonly used phosphonated ruthenium(II) polypyridyl complex, which is reported to have near quantitative injection yield. We find that IET occurs through space rather than through the linkers, due to the tilted orientation of the adsorbed porphyrins in direct contact with the metal oxide surface. As a result, the anchoring groups have a less significant effect on IET dynamics than for adsorbates exhibiting through-linker injection. Experiments are supported by DFT calculations, including the analysis of different electron-injection pathways. Direct IET offers the advantage of the selection of anchoring groups based solely on chemical/photoelectrochemical stability and synthetic viability, irrespective of the electronic coupling of the anchoring group to the metal oxide surface.
AB - This study probes a series of linkers and anchoring groups for direct interfacial electron transfer (IET) from high-potential porphyrins into semiconductor surfaces. Eight different linker-anchor combinations of CF3-substituted, high-potential porphyrins were designed, synthesized, and characterized. Specifically, a series of four anchors was examined (carboxylate, hydroxamate, phosphonate, and silatrane), along with two different linkers (phenylene and benzanilidylene), which differ in terms of their electronic conjugation and overall length. The electrochemical and photophysical properties of the porphyrins were evaluated by steady-state and transient spectroscopies in solution and on mesoporous SnO2 substrates for use as dye photosensitizers in aqueous photoelectrochemical cells. IET dynamics were measured using time-resolved terahertz (TRTS) and transient absorption spectroscopies. From TRTS measurements, injection yields were determined relative to a commonly used phosphonated ruthenium(II) polypyridyl complex, which is reported to have near quantitative injection yield. We find that IET occurs through space rather than through the linkers, due to the tilted orientation of the adsorbed porphyrins in direct contact with the metal oxide surface. As a result, the anchoring groups have a less significant effect on IET dynamics than for adsorbates exhibiting through-linker injection. Experiments are supported by DFT calculations, including the analysis of different electron-injection pathways. Direct IET offers the advantage of the selection of anchoring groups based solely on chemical/photoelectrochemical stability and synthetic viability, irrespective of the electronic coupling of the anchoring group to the metal oxide surface.
UR - http://www.scopus.com/inward/record.url?scp=85049391116&partnerID=8YFLogxK
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U2 - 10.1021/acs.jpcc.7b12405
DO - 10.1021/acs.jpcc.7b12405
M3 - Article
VL - 122
SP - 13529
EP - 13539
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 25
ER -