Photoelectro Degradation of Rhodamine B on Co-Doped TiO<sub>2</sub> Films under Visible Light

Abstract

In a single photoreactor, the degradation of rhodamine B (RhB) was studied on TiO2 and Co-doped TiO2 (Co-TiO2) films under visible light. The results show that the degradation rate of RhB by photocatalytic (PC) and photosensitization (PS) on Co-TiO2 films is quicker than that by PS degradation on TiO2 film. However, a fast N-de-ethylation leads to the increase in degradation rate unsatisfactory. When a bias potential was applied onto Co-TiO2 films, the degradation rate of RhB greatly increased. This can be attributed to the generation of more hydroxyl radicals on Co-TiO2 anodes and cathode. These OH⋅ radicals attack the chromophoric structure of RhB. In addition, with the bias potential application, the optimal Co2+ dopant concentration increases from 0.02 % to 0.4%.