Oxygen Vacancies\nand Lattice Distortion Synergistically\nEnhanced Piezocatalysis of CaZn<sub>2</sub>(BO<sub>3</sub>)<sub>2</sub> for Nonantibiotic Pharmaceutical Degradation

Piezocatalysis, an emerging green and advanced oxidation\ntechnology,\nhas recently been widely researched in environmental treatment. However,\nthe limited polarization efficiency of the piezocatalyst is a serious\nbottleneck for its practical application. The search for an excellent\npiezocatalyst with a high piezoelectric coefficient and abundant reactive\nsites remains an urgent task that needs to be developed. Herein, a\npiezocatalyst, CaZn<sub>2</sub>(BO<sub>3</sub>)<sub>2</sub> (CZBO),\nobtained by quenching has an excellent piezocatalysis, which exhibited\nsuperior activity for ibuprofen (IBP) and carbamazepine (CBZ) removal\nwith 100% and 83.8% efficiency under ultrasonic cavitation (120 W,\n40 kHz) within 36 min, respectively. The outstanding piezocatalytic\ndegradation was attributed to the strong polarization of the material\nunder the synergistic effect of oxygen vacancies (OVs) and lattice\ndistortion, which effectively facilitated the generation of a high\nconcentration of reactive oxygen species (ROS). The lattice distortion\ninduced by O-deficient [BO<sub>3</sub>] plane units can promote the\ne<sup>–</sup> and h<sup>+</sup> pair separation and transportation,\nand the OVs with abundant electron-rich regions can significantly\ndecrease O–O bond activation energy, thus collaboratively contributing\nto the high production of ROS for IBP and CBZ degradation. This work\nprovides a simple avenue for enhancing piezoelectric polarization\nbased on the OVs and lattice distortion and proposes insights into\nthe reaction mechanisms for degrading nonantibiotic pharmaceuticals\nin wastewater.