Z-scheme Bi4O5Br2/MIL-88B(Fe) heterojunction for boosting visible light catalytic oxidation of tetracycline hydrochloride

Bi4O5Br2/MIL-88B(Fe) Z-scheme heterojunction photocatalyst is fabricated by a facile hydrothermal followed by a coprecipitation method. The heterojunction catalyst greatly improved the visible light utilization and has shown excellent photodegradation performance for tetracycline hydrochloride (TCH). The high oxidation capability, unique charge migration, and enhanced photogenerated charge carrier separation of Z-scheme Bi4O5Br2/MIL-88B(Fe) heterojunction simultaneously contributed to improved catalytic performance. Mean-while, Z-scheme Bi4O5Br2/MIL-88B(Fe) heterojunction has achieved the highest photodegradation of TCH with-93.04 % within 80 min. In addition, the time-resolved photoluminescence (PL) emission decay spectra confirmed a prolonged lifetime of electron excitation with a fluorescence lifetime of-1.08 ns compared with Bi4O5Br2 (t = 0.95 ns). Furthermore, following operating conditions, such as pH, solution concentration, various ionic species, etc., the Bi4O5Br2/MIL-88B(Fe) heterojunction has shown excellent photodegradation of TCH in various environmental conditions with high photostability. Additionally, a substantial charge transfer mecha-nism and TCH photodegradation pathway were explained. This work demonstrates a promising approach to constructing other high-efficiency Z-scheme heterojunction materials for wastewater treatments.