Visible-light induced ofloxacin photodegradation catalyzed by the S-scheme Bi2MoO6/NH2-MIL-68(In) heterojunction: Interfacial engineering, DFT calculations, and toxicity assessment

The construction of photocatalysts with high efficiencies for visible light utilization and rapid migration of photoinduced charge carriers is essential for efficient photodegradation of contaminants in water. Thus, a novel Bi2MoO6/NH2-MIL-68(In) S-scheme heterostructure photocatalyst was synthesized via a hydrothermal method. The ofloxacin photodegradation efficiency of optimized BMN-2 reached 100 % within 90 min of visible-light illumination. In addition, an S-scheme charge migration pathway was confirmed within BMN-2 based on work function calculations, in situ XPS, and ESR studies. The photocatalytic mechanism, potential intermediates, and four photodegradation pathways were proposed from theoretical calculations and experimental studies. In addition, h+, •O2–, and •OH were the predominant active species identified via scavenger experiments and ESR spectroscopy. Moreover, the comprehensive toxicity of the degraded OFL solution was lower than that of the initial solution, as indicated by QSAR predictions and E. coli cultivation.