Role of Iron and Chromium in the Photocatalytic Activity of Titanium Dioxide Films on Stainless Steel

Photocatalytically active titanium dioxide films have been formed on stainless steel grids via solgel process followed by heat treatment in the temperature range of 450-550 degrees C. During UV irradiation of the films in an aqueous solution of the Rhodamine B dye and in distilled water we have detected iron and chromium dissolution from uncoated grid regions and the deposition of iron and chromium compounds onto the titanium dioxide surface. The deposition rate of these compounds increases with annealing temperature, which leads to a decrease in the photocatalytic activity of the films.