Enhanced visible-light photocatalytic degradation of tetracycline antibiotic by 0D/2D TiO2(B)/BiOCl Z-scheme heterojunction: Performance, reaction pathways, and mechanism investigation

Abstract

The preparation of Z-scheme heterojunction photocatalysts with outstanding redox capability has become a promising development direction for environmental remediation. Thereby, zero-dimensional/two-dimensional (0D/2D) TiO2(B)/BiOCl Z-scheme heterojunctions were successfully prepared using a simple hydrothermal method. Numerous experiments have indicated that the photocatalytic performance of the composites (0.03671 min-1) for tetracycline (TC) was superior to that of either pristine BiOCl (0.01671 min-1) or TiO2(B) (0.00998 min−1) because of the internal electric field constructed at the heterogeneous interface. The cycling experiments showed that the optimized TiO2(B)/BiOCl heterostructure (TBC-50) remains capable of photodegrading over 80% of TC within 100 min after 4 rounds. Moreover, we thoroughly investigated the photo-induced electron transfer routes, photocatalytic degradation pathways and proposed a Z-scheme heterojunction pattern by utilizing density functional theory (DFT) calculations and liquid chromatography-mass spectrometer (LC-MS). Finally, by virtue of quantitative structure–activity relationship (QSAR) analysis, we have proven that degradation intermediates are less toxic than TC, demonstrating the efficacy of the photocatalytic process. This work opens up new insights into the preparation of superior photocatalysts for ecological remediation.