Degradation of leather dye on TiO2: A study of applied experimental parameters on photoelectrocatalysis

TiO2 supported on ITO (indium tin oxide coated glass) was prepared and its photocatalytic activity was determined by photo-oxidation of commercial leather dye in aqueous solution illuminated with UV light. A vision of the use of the heterogeneous photocatalysis/electrochemically assisted degradation is discussed. Several operational parameters to achieve optimum efficiency of this photodegradation system are presented, such as the influence of temperature, applied potential, pH, initial dye concentration and choice of a UV source. The results indicate that the dye can be degraded totally and mineralized into inorganic products such as NH4+ ions. Decolorization ratios higher than 90% were observed during a period of 480 min. Relating the initial concentration with the approximate azo dye molar mass the formation of ≈96.79% NH4+ was calculated. FT-Raman and FT-IR spectroscopies indicated the influence the supporting electrolyte had on the process.