High‐Efficiency Reactive Oxygen Species Generation by Multiphase and TiO₆ Distortion‐Mediated Superior Piezocatalysis in Perovskite Ferroelectrics

Abstract Piezocatalysis, governed by piezo‐potential within piezoelectrics, has gained prominence for reactive oxygen species (ROS) generation, which is significant to environmental and biological applications. However, designing piezocatalysts with excellent piezocatalytic performance in a wide temperature and efficient charge carrier separation ability is still challenging. Herein, eco‐friendly BaTiO₃ (BT)‐based perovskite ferroelectrics with tailored multiphase coexistence in a wide temperature range are constructed to boost higher piezoelectricity and large piezo‐potential, which is attributed to decreased polarization anisotropy by flat Gibbs energy profile. Elevated piezo‐potential in designed BT‐based piezocatalyst guarantees high‐efficient generation rate of •OH (200 µmol g⁻¹ h⁻¹) and •O₂⁻ (40 µmol g⁻¹ h⁻¹) by ultrasound stimulation, which is 3.5 times more than that of pure BT. Besides, piezocatalytic capacity to degrade dye wastewater shows a rate constant of 0.0182 min⁻¹ and gives an antibacterial rate of 95% within 30 min for eliminating E. coli. Theoretical simulations validate that the local distortion of TiO₆ octahedra also contributes to piezocatalytic performance by inducing electron–hole pairs separation in real space, and better response to slight structural deformation. This work is important to design high‐performance piezocatalysts with high‐efficiency ROS generation for sewage treatment and sonodynamic therapy.