Visible-light-induced photodegradation enhancement of methyl orange over bismuth oxybromide through a semiconductor mediated process

Bismuth oxybromide (BiOBr) has attracted a resurgence of interest due to the outstanding visible light driven photocatalytic performance, which has been widely reported. However, its photosensitization degradation performance of methyl orange (MO) is limited possibly caused by low negative LUMO (lowest unoccupied molecular orbitals) level of MO molecules. The work presented here deals with the improved photodegradation behavior of methyl orange molecules onto BiOBr in the presence of Rhodamine B (RhB, as photosensitizer) through a semiconductor-mediated process. It was found that MO could be photodecomposed much effectively under the assistance of RhB molecules from aqueous solution. The photosensitization process which occurred between RhB and BiOBr is of photochemical origin and responsible for the boosted photodegradation behavior towards MO, which strongly depends on the irradiation time, BiOBr dosage and concentration of model contaminant (MO) and photosensitizer (RhB).