Influence of the Metal Work Function on the Photocatalytic Properties of TiO2 Layers on Metals |
| |
Authors: | Janna Freitag Prof. Dr. Detlef W. Bahnemann |
| |
Affiliation: | 1. Institut für Technische Chemie, Leibniz Universit?t Hannover, Callinstr. 3, D‐30167 Hannover (Germany);2. Laboratory for Nanocomposite Materials, Department of Photonics, Faculty of Physics, Saint Petersburg State University, Ulyanovskaya 3, Saint Petersburg, 198504 (Russia) |
| |
Abstract: | The photocatalytic properties of titanium dioxide (TiO2) layers on different metal plates are investigated. The metal–semiconductor interface can be described as a Schottky contact, and is part of a depletion layer for the majority carriers in the semiconductor. Many researchers have demonstrated an increase in the photocatalytic activity, due to the formation of a metal–semiconductor contact that are obtained by deposition of small metal islands on the semiconductor. Nevertheless, the influence of a Schottky contact remains uncertain, sparking much interest in this field. The immobilization of nanoparticulate TiO2 layers by dip‐coating on different metal substrates results in the formation of a Schottky contact. The recombination rate of photoinduced electron–hole pairs decreases at this interface provided that the thickness of the thin TiO2 layer has a similar magnitude to the depletion layer. The degradation of dichloroacetic acid in aqueous solution and of acetaldehyde in a gas mixture is investigated to obtain information concerning the influence of the metal work function of the back contact on the efficiency of the photocatalytic process. |
| |
Keywords: | acetaldehyde degradation dichloroacetic acid degradation metal– semiconductor interfaces photocatalysis titanium dioxide |
|
|