The insufficient active sites, low separation efficiency of free carriers and poor capacity to generate active free radicals are limitations of asymmetrical BiFeO₃ in piezocatalysis. To address these issues, BiFeO₃ hollow nanospheres with exposed abundant catalytic active sites were fabricated via a solvothermal method for the first time. In addition, surface iodine-grafting was introduced, resulting in a local electric field and the conduction band potential of BiFeO₃ closer to the O₂/·O₂^– redox potential (-0.33 eV). It facilitated charge transmission and active species generation to remove bisphenol A under ultrasonic vibration. Thus, the iodine-grafted BiFeO₃ hollow nanospheres could completely degrade 20 mL bisphenol A (10 ppm) within 60 min with a relatively fast rate constant of 0.153 min⁻¹, which was 4.5 times higher than that of un-grafted BiFeO₃. This work provides a feasible approach to construct efficient piezocatalysts for industrial wastewater purification.

活性位点不足、自由载流子分离效率低和产生活性自由基能力差是不对称BiFeO ₃在压电催化中的局限性。为了解决这些问题，首次通过溶剂热法制备了具有大量催化活性位点的BiFeO _{3空心纳米球。}此外，引入表面碘接枝，导致局部电场和BiFeO ₃的导带电势更接近O ₂ /·O ₂ ^-氧化还原电势（-0.33 eV）。它促进了电荷传输和活性物质的产生，以在超声波振动下去除双酚 A。因此，碘接枝的 BiFeO ₃空心纳米球可以在60分钟内完全降解20 mL双酚A（10 ppm），速率常数相对较快，为0.153 min ^-1，是未接枝BiFeO ₃的4.5倍。这项工作为构建用于工业废水净化的高效压电催化剂提供了一种可行的方法。