Plana, D and Fermín, DJ (2016) Photoelectrochemical activity of colloidal TiO2 nanostructures assembled at polarisable liquid/liquid interfaces. Journal of Electroanalytical Chemistry, 780. 373 -378. ISSN 1873-2569

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Photoelectrochemical responses arising from the heterogeneous hole-transfer from colloidal TiO2 nanoparticles to ferrocene species across the polarizable water/1,2-dichloroethane (DCE) interface are investigated as a function of the formal redox potential of the electron donor. The interfacial assembly of electrostatically stabilized 5 nm TiO2 colloids was monitored by impedance measurements at various Galvani potential difference across the liquid/liquid interface. The onset potential of the photocurrent responses is close to the potential at which the excess interfacial charge increases due to the assembly of the TiO2 nanoparticles. However, a closer examination of the potential dependence of these two parameters show that the interfacial excess charge is not solely dependent on the adsorption of charged nanoparticles at the interface. We also provide strong evidence that the photoelectrochemical responses are determined by the relationship between rate of electron capture at the nanoparticle surface and surface recombination processes, rather than the interfacial oxidation of the ferrocene derivatives. Second order surface recombination constants of the order of 10− 3 cm2 s− 1 were estimated, which are consistent with a ~ 0.6 quantum yield for the heterogenous hole-transfer.

Item Type: Article
Additional Information: This is the final published version of the article (version of record). It first appeared online via Elsevier at - please refer to any applicable terms of use of the publisher.
Uncontrolled Keywords: Photocurrent; Liquid/liquid interfaces; TiO2 nanoparticles; Ferrocene
Subjects: Q Science > QD Chemistry
Divisions: Faculty of Natural Sciences > School of Chemical and Physical Sciences
Depositing User: Symplectic
Date Deposited: 06 Mar 2017 16:45
Last Modified: 08 Apr 2019 08:43

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