Photoelectrocatalysis Study of the Decolorization of Synthetic Azo Dye Mixtures on Ti/TiO2

The main goal of this paper was to study the degradation of synthetic dye mixtures, using photoelectrocatalytic properties of particulate films of TiO2 supported on titanium substrate and excited by UV-Vis radiation. The dyes' decolorizations were measured by spectrophotometric methods and ratios higher than 87 % for a period of 300 min. The stirring speed was an important operational parameter, increasing 12 times the photoelectrocatalytic efficiency. Data analysis has also shown that, under the conditions of this study, the Cl- present in the electrode/solution interface can be oxidized to generate the ClO3 (-) species. These species turned out to be powerful oxidizing agents, which together with the hydroxyl radical, work in the efficiency of the photocatalytic process. Scanning electron microscopy images of TiO2 film on Ti with indication of the thickness and spherical shape of the sample studied were obtained.