Abstract
In this work we investigate influence of an externally applied bias on the photocatalytic performance of self-organized TiO2 nanotube layers. These layers were grown by anodization of titanium in fluoride containing electrolytes and have different geometric dimensions. Since the layers are grown directly on the Ti substrate, a very good electrical backside contact is directly provided. Therefore, we use the nanotube layers/Ti structures as photo-anodes for the UV light induced photocatalytic decomposition of acid orange 7. For comparison, we use TiO2 nanopowder (Degussa P25) compacted also on a Ti sheet. The present results demonstrate that the photocatalytic activity of self-organized TiO2 nanotube layers can significantly be increased by electrochemical bias. (C) 2007 Elsevier B.V. All rights reserved.