Ba²⁺-doping introduced piezoelectricity and efficient Ultrasound-Triggered bactericidal activity of brookite TiO₂...

Exploring highly efficient ultrasound-triggered catalysts is pivotal for various areas. Herein, we presented that Ba²⁺ doped brookite TiO₂ nanorod (TiO₂: Ba) with polarization-induced charge separation is a candidate. The replacement of Ba²⁺ for Ti⁴⁺ not only induced significant lattice distortion to induce polarization but also created oxygen vacancy defects for facilitating the charge separation, leading to high-efficiency reactive oxygen species (ROS) evolution in the piezo-catalytic processes. Furthermore, the piezocatalytic ability to degrade dye wastewater demonstrates a rate constant of 0.172 min^-1 and achieves a 100 % antibacterial rate at a low dose for eliminating E. coli. This study advances that doping can induce piezoelectricity and reveals that lattice distortion-induced polarization and vacancy defects engineering can improve ROS production, which might impact applications such as water disinfection and sonodynamic therapy.