Photochemistry of Ru(bpy)2(dcbpy)2+ on Al2O3 and TiO2 Surfaces. An Insight into the Mechanism of Photosensitization

Vinodgopal, K.; Hua, Xing; Dahlgren, Robin L.; Lappin, A. Graham; Patterson, L. K.; Kamat, Prashant V.

doi:10.1021/j100027a032

Cited by 157 publications

(155 citation statements)

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“…[4][5][6] We report here on the kinetics for back electron transfer for several variants of the classic tris polypyridyl ruthenium/nanocrystalline titanium dioxide system (eq 1). We note that this system has figured prominently in the development of several of the most promising current dye-based energy conversion systems [7][8][9][10][11][12][13][14] sin part because it was one of the first systems to exhibit both efficient forward electron transfer and comparatively slow back ET (but, nevertheless, fast by conventional electrochemical standards). Slow back reactivity is typically a criterion for achieving both a high degree of net charge separation and a high photovoltage.…”

Section: Introductionmentioning

confidence: 99%

In Search of the Inverted Region: Chromophore-Based Driving Force Dependence of Interfacial Electron Transfer Reactivity at the Nanocrystalline Titanium Dioxide Semiconductor/Solution Interface

Yan¹,

Prieskorn²,

Kim³

et al. 2000

J. Phys. Chem. B

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Intentional variations of the driving force for back electron transfer from titanium dioxide to a surface-bound redox couple, via synthetic alteration of the couple's formal potential, show that the reaction takes place in the Marcus normal region; i.e., rates become faster as the driving force increases. Variable-temperature rate measurements show that back ET is thermally activated, with the activation barrier decreasing with increasing driving force, as expected for a normal region process. The observation of normal region behavior, despite the existence of overall reaction driving forces that significantly exceed the likely reorganization energy, is attributed to the occurrence of a sequential electron-and proton-transfer process. The sequential process yields a driving force for the rate-determining electron-transfer step that is considerably smaller than the overall reaction driving force. The sequential electron-and proton-transfer mechanism also provides an explanation for the pH independence of the back-ET kinetics. Variable-temperature rate measurements additionally point toward a high degree of nonadiabaticitys3-5 orders of magnitude of rate attenuation due solely to inefficient electronic coupling. The physical basis for the effect presumably is in the need to traverse eight bonds, some of them saturated, in the back-ET process. Together with the barrier activation effects, the reaction nonadiabaticity accounts for the slow rates for back ET (ca. 10 7 s -1) and, therefore, much of the ability of metal-to-ligand charge-transfer type chromophores to function effectively as sensitizers in TiO 2 -based photoelectrochemical cells. The findings also suggest that more efficient cells could be constructed by extending the chemical linkage between the dye and semiconductor and by further decreasing the driving force for the back-ET process.

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Section: Introductionmentioning

confidence: 99%

In Search of the Inverted Region: Chromophore-Based Driving Force Dependence of Interfacial Electron Transfer Reactivity at the Nanocrystalline Titanium Dioxide Semiconductor/Solution Interface

Yan¹,

Prieskorn²,

Kim³

et al. 2000

J. Phys. Chem. B

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“…Carboxyl [49][50][51][52] and phosphonate [53][54][55] are the two most important terminal groups of Ru-complexes that have been studied. Choi's team has studied the photocatalytic activity of semiconductors using Ru-complexes with various terminal groups.…”

Section: An Overview Of Dyes As Photosensitizersmentioning

confidence: 99%

Dye-Sensitized Photocatalytic Water Splitting and Sacrificial Hydrogen Generation: Current Status and Future Prospects

2017

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Today, global warming and green energy are important topics of discussion for every intellectual gathering all over the world. The only sustainable solution to these problems is the use of solar energy and storing it as hydrogen fuel. Photocatalytic and photo-electrochemical water splitting and sacrificial hydrogen generation show a promise for future energy generation from renewable water and sunlight. This article mainly reviews the current research progress on photocatalytic and photo-electrochemical systems focusing on dye-sensitized overall water splitting and sacrificial hydrogen generation. An overview of significant parameters including dyes, sacrificial agents, modified photocatalysts and co-catalysts are provided. Also, the significance of statistical analysis as an effective tool for a systematic investigation of the effects of different factors and their interactions are explained. Finally, different photocatalytic reactor configurations that are currently in use for water splitting application in laboratory and large scale are discussed.

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“…3(c)), with a shift to a higher wavelength (from 540 to 560 nm). The difference in the absorption peak is due to the binding of anthocyanin in the extract to the TiO 2 surface [17]. Based on the J-V curve, the fill factor (FF) and solar cell efficiency ( η ) were determined using equations (1) and (2) respectively.…”

Section: Characterization and Measurementmentioning

confidence: 99%

Dye-Sensitized Solar Cells Using Natural Dyes Extracted from Roselle (<i>Hibiscus Sabdariffa</i>) Flowers and Pawpaw (<i>Carica Papaya</i>) Leaves as Sensitizers

Danladi¹

2016

JENR

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Dye-sensitized solar cells (DSSCs) were fabricated using natural dyes extracted from roselle flowers and carica papaya leaves extract as photosensitizers. The photovoltaic perfomance of the DSSCs were evaluated under 100 mAcm -2 light intensity. The roselle (Hibiscus Sabdariffa) extract sensitized solar cell gave a short circuit current density (Jsc) of 0.180 mAcm -2 , an open circuit voltage (Voc) of 0.470 V, a fill factor (FF) of 0.552, and an overall solar energy conversion efficiency (η) of 0.046%. Also, the pawpaw leaves extract sensitized cell gave a Jsc of 0.094 mAcm -2 , Voc of 0.433 V, FF of 0.544 yielding a conversion efficiency of 0.022%. The cell sensitized by the roselle extract shows better sensitization, which was in agreement with the broadest spectrum of the extract adsorbed on TiO 2 film. The sensitization performance related to interaction between the dye and TiO 2 surface is discussed.

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Photochemistry of Ru(bpy)2(dcbpy)2+ on Al2O3 and TiO2 Surfaces. An Insight into the Mechanism of Photosensitization

Cited by 157 publications

References 0 publications

In Search of the Inverted Region: Chromophore-Based Driving Force Dependence of Interfacial Electron Transfer Reactivity at the Nanocrystalline Titanium Dioxide Semiconductor/Solution Interface

In Search of the Inverted Region: Chromophore-Based Driving Force Dependence of Interfacial Electron Transfer Reactivity at the Nanocrystalline Titanium Dioxide Semiconductor/Solution Interface

Dye-Sensitized Photocatalytic Water Splitting and Sacrificial Hydrogen Generation: Current Status and Future Prospects

Dye-Sensitized Solar Cells Using Natural Dyes Extracted from Roselle (<i>Hibiscus Sabdariffa</i>) Flowers and Pawpaw (<i>Carica Papaya</i>) Leaves as Sensitizers

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Photochemistry of Ru(bpy)2(dcbpy)2+ on Al2O3 and TiO2 Surfaces. An Insight into the Mechanism of Photosensitization

Cited by 157 publications

References 0 publications

In Search of the Inverted Region: Chromophore-Based Driving Force Dependence of Interfacial Electron Transfer Reactivity at the Nanocrystalline Titanium Dioxide Semiconductor/Solution Interface

In Search of the Inverted Region: Chromophore-Based Driving Force Dependence of Interfacial Electron Transfer Reactivity at the Nanocrystalline Titanium Dioxide Semiconductor/Solution Interface

Dye-Sensitized Photocatalytic Water Splitting and Sacrificial Hydrogen Generation: Current Status and Future Prospects

Dye-Sensitized Solar Cells Using Natural Dyes Extracted from Roselle (&lt;i&gt;Hibiscus Sabdariffa&lt;/i&gt;) Flowers and Pawpaw (&lt;i&gt;Carica Papaya&lt;/i&gt;) Leaves as Sensitizers

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Dye-Sensitized Solar Cells Using Natural Dyes Extracted from Roselle (<i>Hibiscus Sabdariffa</i>) Flowers and Pawpaw (<i>Carica Papaya</i>) Leaves as Sensitizers