On Oxygen Activation at Rutile- and Anatase-TiO2

By Marta Buchalska, M. Kobielusz, Anna Matuszek, Michał Pacia, S. Wojtyła, W. Macyk. 2015

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The rutile form of titanium dioxide (r-TiO2) usually shows a photocatalytic activity lower than that of anatase-TiO2 (a-TiO2). Nevertheless, there are numerous examples of sometimes unexpectedly high activity of r-TiO2. This material may appear to be particularly useful when a noncomplete and selective photocatalytic oxidation of organic substrates is required. On the basis of literature examples and our own studies, we compare the photocatalytic activities of r-TiO2, a-TiO2, and r-TiO2/a-TiO2 composites. Because of a significantly better oxygen adsorption at the surface of r-TiO2 and a lower redox potential of the excited electron, more efficient O2•– production takes place at the surface of rutile. As a consequence, generation of 1O2 (involving O2 reduction and the subsequent oxidation of superoxide) and reduction of H2O2 to OH– and HO• are also favored with this material. Therefore, r-TiO2 can be considered to be a particularly good photocatalyst for activation of molecular oxygen. On the other hand, a...

Subfields: Materials Chemistry, Renewable Energy, Sustainability and the Environment

View Paper: https://www.semanticscholar.org/paper/438790dd69442c79dce44f56a1669d5e2acc78e8