A recyclable magnetic piezoelectric composite Fe3O4/SrBi2Ta2O9 for efficient antibiotic removal in water under ball milling

Confronting the significant environmental and public health challenges posed by the escalating threat of antibiotic pollution, piezocatalytic technology has emerged as a promising solution. However, its practical implementation remains constrained by the low degradation efficiency with powdered piezocatalysts, which face the challenge of difficult recovery, as well as the low degradation efficiency caused by the coverage of active sites during the processes of recovery or degradation. Herein, we used the hydrothermal method to load Fe₃O₄ onto SrBi₂Ta₂O₉ (Fe/SBTO). The results demonstrated that Fe/SBTO achieved degradation efficiencies of 96.8% for Oxytetracycline (OTC) and 97.0% for Tetracycline (TC) within 30 min. Its degradation efficiency for OTC was 2.34 times higher than that of SBTO and even 3.13 times higher than that of conventional piezoelectric material T-BaTiO₃. The high degradation efficiency of the material can be attributed to the built-in electric field formed between Fe/SBTO heterojunction under ball milling, which promotes the separation of the piezo-induced charges, thereby enhancing the generation of singlet oxygen and hole. Furthermore, the composite piezocatalyst can be easily recovered using magnets, with a recovery rate of up to 90%. This work presents a promising approach for addressing antibiotic pollution in water and offers insights into enhancing traditional powder materials.