Synergistic effect of bifunctional Co-TiO2 catalyst on degradation of Rhodamine B: Fenton-photo hybrid process

The synergistic effect of two different advanced oxidation technologies, heterogeneous sulfate radical based Fenton and TiO2 photocatalysis, was observed through a drastic enhancement of Rhodamine B removal in Co-TiO2/Oxone/Photo process. Our catalysts were obtained by a citric acid-assisted sol-gel method and Rhodmine B was used as model organic pollutant. The cobalt species in Co-TiO2 play a crucial role of integration Fenton with TiO2 photocatalysis in one heterogeneous hybrid system that not only active Oxone to produce SO4-, but also enhance the photocatalytic activity of TiO2 as well as extend its absorption spectrum to visible region, thus it can be defined as a type of bifunctional catalyst. The influence of the pH, [Oxone]/[RhB] molar ratio and catalyst concentration of the catalytic performance were investigated. The Rhodamine B can be eliminated 100% and TOC removal of solution can reach 68% at the optimum conditions by Photo/Co-TiO2/Oxone process. Moreover, the catalyst was demonstrated to have good stability and reusability.