Piezo-photothermal accelerates Co³⁺/Co²⁺ cycle to boost PMS activation over Co₃O₄/PTFE for efficient antibiotic...

In peroxymonosulfate (PMS) activation processes, the relatively slow redox kinetics of metal ions have been a key factor limiting both PMS activation efficiency and photocatalytic performance. In this study, a Co₃O₄/PTFE composite with integrated piezoelectric and photothermal properties was successfully constructed, which significantly enhanced the Co³⁺/Co²⁺ cycle and thereby promoted PMS activation for efficient tetracycline (TC) degradation. Under the dual stimulation of mechanical agitation and visible light irradiation, the Co₃O₄/PTFE composite exhibited enhanced photothermal conversion and piezoelectric performance, which significantly promoted the generation of reactive species such as SO₄^•- and •OH. Compared with pristine Co₃O₄, CoP-2 demonstrated a superior TC degradation efficiency of up to 83% in the PMS system. X-ray photoelectron spectroscopy (XPS) analysis revealed that the introduction of polytetrafluoroethylene (PTFE) induced interfacial strain, modulated the valence state of cobalt species, and optimized the surface electronic structure, thereby facilitating the formation of active sites and enhancing electron transfer processes. Free radical trapping experiments further identified the dominant reactive species and revealed the underlying synergistic catalytic mechanism. Moreover, CoP-2 maintained excellent stability after multiple degradation cycles. This study provides a novel strategy for the design of multifunctional synergistic catalysts and expands the application potential of piezo-photothermal/PMS systems in environmental purification.