The Effect of Doping with Ti(IV) and Sn(IV) on Oxygen Reduction at Hematite Electrodes
- 1 January 2001
- journal article
- research article
- Published by The Electrochemical Society in Journal of the Electrochemical Society
- Vol. 148 (2), E85-E91
- https://doi.org/10.1149/1.1341239
Abstract
We examined the reduction of oxygen at doped hematite (alpha -Fe2O3) electrodes to determine how the identity of the dopant affected the reaction and how changes in reactivity compared with changes in dopant concentration. Our results indicated that Sn(IV) and TI(IV) dopants have a similar effect on the open-circuit potential, cathodic transfer coefficient, and exchange current density, suggesting that any bandgap states associated with the introduction of dopants, and directly involved in the reduction of oxygen have similar energies. The greatest difference between the electrodes doped with Sn(IV) and Ti(IV) was in the apparent cathodic transfer coefficient. The cathodic transfer coefficients for the Sn-doped electrodes were slightly smaller than those for the Ti-doped, suggesting that the density of interface states is greater in the Sn-doped electrodes. In comparing electrodes with two different dopant concentrations, we found that the relative increase in reactivity was significantly less than the increase in dopant concentration. This may be due to the electrochemical creation of surface Fe(II) sites that catalyze the reduction of O-2 Other factors that may also contribute include bandgap states associated with the dopants and the fact that not all the dopants lead to creation of Fe(II) sites. (C) 2001 The Electrochemical Society. All rights reserved.Keywords
This publication has 28 references indexed in Scilit:
- Electrochemical Behavior of Cr2 O 3 / Fe2 O 3 Artificial Passive Films Studied by In Situ XANESJournal of the Electrochemical Society, 1998
- Spectroelectrochemical Studies of Passivation and Transpassive Breakdown Reactions of Stainless SteelJournal of the Electrochemical Society, 1997
- Reduction of Substituted Nitrobenzenes by Fe(II) in Aqueous Mineral SuspensionsEnvironmental Science & Technology, 1995
- Electrocatalysis of oxygen reduction at well-defined iron oxide electrodesElectrochimica Acta, 1994
- The mechanism of the oxygen reduction on rust-covered metal substratesCorrosion Science, 1994
- Oxygen reduction on titanium-doped α-Fe2O3 electrodes in aqueous alkaliAustralian Journal of Chemistry, 1983
- Photoactivity of doped αFe2O3 electrodesSolar Energy Materials, 1982
- Semiconductor Electrodes: XXI . The Characterization and Behavior of n‐Type Electrodes in Acetonitrile SolutionsJournal of the Electrochemical Society, 1979
- The electrical properties of alpha ferric oxide—II.Journal of Physics and Chemistry of Solids, 1963
- The electrical properties of alpha ferric oxide—I.Journal of Physics and Chemistry of Solids, 1963