An innovative Z-type Sb2S3/In2S3/TiO2 heterostructure: superior performance in the photocatalytic removal of levofloxacin and mechanistic insight

Abstract

In this study, Sb₂S₃/In₂S₃/TiO₂ (SIT) heterojunction photocatalysts were prepared by a simple two-step hydrothermal method and applied to the photocatalytic degradation of levofloxacin (LEV). After 160 min of reaction under visible light, the SIT heterojunction photocatalyst degraded 10 mg L⁻¹ LEV at a rate of 86.7%. The degradation of LEV follows pseudo-first-order kinetics with a rate constant 1.16 × 10⁻² min⁻¹, which is 1.42, 1.22 and 1.05 times higher than that of TiO₂, SI and IT, respectively. Meanwhile, the SIT photocatalysts also showed high photocatalytic activity for other antibiotics. The enhanced photocatalytic activity of the ternary heterostructures was attributed to the full-spectrum response and the synergistic effect of the dual Z-type heterojunctions, which improved the visible light absorption and facilitated the charge separation. In addition, ˙OH and ˙O₂⁻ play a dominant role in the photodegradation process. This work contributes to the design of novel photocatalytic materials with dual Z-type heterojunctions and efficient photocatalysts for the degradation of antibiotics.