Room Temperature Synthesis of BiOI/Bi5O7I p-n Heterojunction with Enhanced Photocatalytic Activity for 17α-Ethynylestradiol

A p-n heterojunction photocatalyst BiOI/Bi5O7I has been synthesized via a mixed solvent method at room temperature. The physical and chemical properties of as-prepared composites were characterized by XRD, SEM, TEM, XPS, UV-vis DRS, BET and PL. The photocatalytic performance of BiOI/Bi5O7I composite was evaluated by the photocatalytic decomposition of 17 alpha-ethinylestradiol (EE2) under visible light irradiation. The results revealed that the BiOI/Bi5O7I composite showed enhanced photocatalytic activity compared to pure BiOI and pure Bi5O7I. The mass ratio of BiOI/Bi5O7I and effect of pH value for photocatalytic activity of BiOI/Bi5O7I composite were investigated. Moreover, the photocatalytic mechanism of the degradation process was thoroughly elucidated. The enhanced photocatalytic performance of the BiOI/Bi5O7I composite should be attributed to fabrication of BiOI/Bi5O7I p-n heterojunction, which was responsible for efficient separation and transfer of electron-hole pairs.