Interfacial coupling mechanism for efficient degradation of tetracycline by heteroatom iodine (I)-doped BiOBr under visible light: Efficacy and driving force

Studies on photocatalytic materials frequently focus on two pivotal metrics: the generation and separation capabilities of photoinduced charge carriers. In this context, we developed a diverse range of BiOBr_xI_1-x solid solutions (x = 1, 0.75, 0.50, 0.25, 0) via a simple room-temperature synthesis. The BiOBr_0.75I_0.25 solid solution demonstrated a remarkable degradation ability (up to 88.4 %) for tetracycline (TC) within a span of 60 min under visible light. This efficiency was attributed to enhanced light absorption within the visible region and improved segregation of photoinduced charges. A systematic study was performed to determine the influence factors of the degradation efficiency and the roles of different reactive species. A comprehensive photocatalytic mechanism was proposed on the basis of the results of X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. Finally, theoretical calculations were integrated with liquid chromatography-mass spectrometry (LC-MS) results to propose a degradation pathway for BiOBr_0.75I_0.25.