Nano Archive

Oxygen Reduction on Iron−Melanin Granular Surfaces

Orive, Alejandro González and Creus, Alberto Hernández and Grumelli, Doris and Benitez, Guillermo A. and Andrini, Leandro and Requejo, Felix G. and Bonazzola, Cecilia and Salvarezza, Roberto C. (2009) Oxygen Reduction on Iron−Melanin Granular Surfaces. The Journal of Physical Chemistry C, 113 (39). p. 17097. ISSN 1932-7447

Full text is not hosted in this archive but may be available via the Official URL, or by requesting a copy from the corresponding author.

Official URL: http://dx.doi.org/10.1021/jp905560d

Abstract

We report the catalytic activity of iron−eumelanin granular deposits supported on graphite for the oxygen reduction in neutral and alkaline solutions. These deposits contain quinone groups and iron−melanin complexes as revealed by XPS, XANES, EXAFS, and IR spectroscopy. Voltammetric data show that the iron−eumelanin system exhibits higher electrocatalytic activity than quinone/hydroquinone films (Q/QH) on the same substrate. In contrast to Q/QH deposits, the iron-containing eumelanin system is able to reduce oxygen with transfer of four electrons, thus allowing the formation of reactive hydroxyl species. Our results can explain the physical chemistry basis of the oxygen-radical induced lipid peroxidation and consequent neurodegeneration of the melanin-containing dopaminergic neurons observed by several authors.

Item Type:Article
Subjects:Material Science > Nanochemistry
ID Code:8092
Deposited By:M T V
Deposited On:07 Jan 2010 10:27
Last Modified:07 Jan 2010 10:27

Repository Staff Only: item control page