Binding and Static Quenching Behavior of a Terthiophene Carboxylate on Monodispersed Zinc Oxide Nanocrystals
| Autor: | Julia E. Rossini, Jon N. Bohnsack, Adam S. Huss, Kent R. Mann, David A. Blank, Wayne L. Gladfelter |
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| Rok vydání: | 2010 |
| Předmět: |
Quenching
Materials science Inorganic chemistry chemistry.chemical_element Langmuir adsorption model Zinc Surfaces Coatings and Films Electronic Optical and Magnetic Materials Ion symbols.namesake chemistry.chemical_compound General Energy Terthiophene Adsorption Nanocrystal chemistry symbols Carboxylate Physical and Theoretical Chemistry |
| Zdroj: | The Journal of Physical Chemistry C. 115:11-17 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp1080143 |
| Popis: | The synthesis of 3′,4′-dibutyl-2-phenyl-2,2′:5′,2′′-terthiophene-5′′-carboxylic acid and its behavior with monodispersed ZnO having diameters from 2.7 to 3.2 nm are reported. The excited state of the dye (E0* = −1.61 V vs NHE) was quenched upon binding to ZnO nanocrystals. Adsorption isotherms were measured for the terthiophene dye in ethanol and fit with a Langmuir model, which gave a size-independent Kads of 2.3 ± 1.0 × 105 M−1. The maximum number of attached dyes per nanocrystal depended on the diameter and was consistent with each dye occupying 0.5 ± 0.1 nm2 at maximum coverage. Deviation from the Langmuir model observed at low dye concentrations was attributed to a small amount of free zinc ion present in solution that binds the carboxylate ions more strongly than do ZnO nanocrystals. Incorporation of the equilibrium expression between zinc ion and free carboxylate into the model provided a satisfactory fit for both the adsorption isotherm experiments and the complex shape of the Stern−Volmer graphs.... |
| Databáze: | OpenAIRE |
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