Highly efficient photocatalytic degradation of norfloxacin via Bi2Sn2O7/PDIH Z-scheme heterojunction: Influence and mechanism

Abstract

The severe pollution caused by antibiotics has prompted considerable concerns in recent decades. In this study, the Bi2Sn2O7/PDIH Z-scheme heterojunction photocatalyst was synthesized and highly photocatalytic activity on norfloxacin was obtained. The degradation of norfloxacin reached 98.71% in 90 min under visible light. The apparent rate constant of norfloxacin (0.4 903 min−1) was 3.65 and 20 times that of PDIH and the Bi2Sn2O7. Meanwhile, XPS, electrochemical, Photoluminescence spectroscopy and electron paramagnetic resonance results showed that Z-scheme charge-transfer process facilitated the spatial carrier separation and preserve redox capability. Furthermore, the degradation intermediates of norfloxacin and their toxicities were evaluated. Finally, in the view of the survey about the impact of different water matrices, it was found that the Bi2Sn2O7/PDIH maintained high efficiency in raw natural water. This work enriched inorganic/organic heterojunction engineering for PDIH, and provided the enormous potential for combining the Bi2Sn2O7 with PDIH to address the antibiotic pollution issues in the actual water treatment.