The construction of the BaTiO₃/Co₃O₄ heterojunction and its piezoelectric-assisted activation of peroxymonosulfate for the degradation of tetracycline

Although peroxymonosulfate (PMS)-based advanced oxidation technology exhibits strong oxidation capacity and fast reaction kinetics, its low activation efficiency limits its practical application. Herein, BaTiO₃/Co₃O₄ composite piezoelectric catalysts were prepared via a template method, and tetracycline hydrochloride (TC-HCl) was used as a model pollutant to evaluate the catalytic performance of PMS activation under ultrasonic vibration. The results show that Co₃O₄ nanosheets are uniformly loaded onto the surface of rod-like BaTiO₃, forming a tightly coupled and well-defined heterojunction structure. Among the composites, BT/Co₃O₄-3 exhibits the best synergistic catalytic effect, achieving a TC-HCl degradation efficiency of 99.48% within 20 min, which is approximately 3.6 times higher than that of pure BaTiO₃. Moreover, the catalyst retains over 90% of its initial activity after five consecutive cycles, demonstrating excellent structural stability and recyclability. These findings confirm the high stability of this material in the piezoelectric-activated PMS system, providing a feasible strategy for the piezoelectric-assisted advanced oxidation treatment of refractory antibiotics.