Yb-doped BiOBr for highly efficient photocatalytic degradation of tetracycline hydrochloride under visible light irradiation

Bismuth oxybromide (BiOBr) is a common photocatalyst for degrading organic pollutants. Due to its low charge separation efficiency and narrow band gap, it is difficult to achieve good results in practical applications. By doping ytterbium ions (Yb3+) into BiOBr, its absorption and utilization of visible light can be improved, thereby enhancing the photocatalytic performance. In this study, a simple one-step hydrothermal method was used to prepare Yb-doped BiOBr photocatalysts with enhanced oxygen vacancies (OVs). Yb0.4/BiOBr excites molecular oxygen and has a low band gap and a high charge separation efficiency. When tetracycline hydrochloride (TCH) is used for photocatalysis, the degradation efficiency can reach 89.38% within 100 minutes, and the reaction rate constant is 1.47 times that of BiOBr without Yb doping. Finally, the possible degradation pathways and intermediates of TCH were investigated by liquid chromatography–mass spectrometry (LC–MS). This study provides a new approach for improving the photocatalytic activity of BiOBr.