A novel Z-scheme heterojunction Bi12O17Br2/TiO2 with exposed {001} facet nanoparticles for the degradation of tetracycline under visible light

The abuse of tetracycline and other drugs makes the water system accumulate with antibiotics and its metab-olites, which generate threat to human life. Photocatalytic degradation was regarded as a crucial technology for the removal of antibiotic drug pollutants from water efficiently under visible light. In this study, a novel Z-scheme heterojunction was developed for tetracycline degradation and the mechanism was studied through preparing efficient photocatalyst Bi12O17Br2/(001)-TiO2. Unlike the traditional Z-scheme heterojunction, (001)-TiO2 acts as an electron syringe in this nanocomposite, promoting the special charge transfer and making the separation and transfer of electron hole pairs more efficient. At the same time, the stacking of layered structure increases the specific surface area than other bismush-based materials, which benefits the adsorption of pol-lutants and increases reactive active site. Results show that the degradation efficiency of BT5 catalyst for tetracycline solution could attain 99.76 % of TC in 50 min. Meanwhile, the BT5 catalyst still maintained a high degradation rate of 93.50 % after four cycles. This study suggested new design ideas for novel Z-scheme in antibiotic pollutant removal.

Automated summary

The abuse of tetracycline and other drugs leads to the accumulation of antibiotics and their metabolites in the water system, posing a threat to human life. This study developed a novel Z-scheme heterojunction for efficient photocatalytic degradation of tetracycline using a Bi12O17Br2/(001)-TiO2 catalyst. Unlike traditional Z-scheme heterojunctions, (001)-TiO2 acts as an electron syringe, promoting special charge transfer and enhancing the efficiency of electron hole pair separation and transfer. The stacked layered structure of the catalyst also increases the specific surface area, allowing for better pollutant adsorption and increased reactive active site. The degradation efficiency of the BT5 catalyst for tetracycline solution reached 99.76% in 50 min, and it maintained a high degradation rate of 93.50% after four cycles. This study provides new design ideas for the removal of antibiotic pollutants using novel Z-scheme structures.