CeO2-modified MIL-101(Fe) for photocatalysis extraction oxidation desulfurization of model oil under visible light irradiation

Abstract CeO2/MIL-101(Fe) catalysts for a photocatalysis-extraction oxidation desulfurization (PEODS) system were designed by introducing different amounts of CeO2 into MIL-101(Fe). And, the materials were further analyzed via some characterization technologies. Moreover, an optimization system, composed of CeO2/MIL-101(Fe), extractant acetonitrile and oxidant H2O2, was selected to remove dibenzothiophene (DBT) from model oil under visible-light irradiation. Evaluation results illustrated that 90% of DBT in oil phase was able to be transformed within 2 h as the adding amount of CeO2, the volume ratio of model oil to acetonitrile and the molar ratio of H2O2 to DBT was 60 mg, 2:1 and 3:1, respectively. Radical scavenger experiments verified that ·OH and ·O2– were main reactive species in the process. The high photocatalytic activity was originated from a synergic effect produced between active sites of CeO2 and active surface of MIL-101(Fe) and formed heterostructure in the catalyst, which broadened optical response ranges and facilitated photoinduced charge separations and transfers. Additionally, a convinced PEODS mechanism was proposed and rationalized.