Piezo-Enhanced Photocatalytic Activity of BaTiO₃-Doped Polyvinylidene Fluoride Nanofibers

In recent decades, with population growth and rapid industrialization, the contamination of water resources has become a pressing concern, with organic pollutants, heavy metals, and other complex compounds playing a significant role. Consequently, the development of novel materials that can harness natural energy and employ it for wastewater treatment represents a crucial objective. In this study, a PVDF/BaTiO₃ composite membrane was synthesized via the electrospinning method. The synthesized materials were subjected to investigation by means of scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). The incorporation of BaTiO₃ resulted in a notable reduction in fiber diameter, with a 2.9-fold decrease observed. Fourier transform infrared spectroscopy (FTIR) revealed that the β-phase fraction decreased from 87.3 to 74.3%, while the γ‑polymorph increased from 10.7 to 20.9%. The catalytic properties of the composite were investigated by subjecting it to the decomposition of methylene blue. The photocatalytic process yielded 61% decomposition, the piezocatalytic process yielded 77% decomposition, and the piezophotocatalytic process (simultaneous exposure to ultrasound and UV-visible light) yielded 98% decomposition in 60 min. The synergetic effect of the two processes was 33.7%. The oxidation mechanism in piezo- and piezophotocatalysis is based on the action of hydroxyl radicals (^•OH). Experimental evidence has demonstrated that the membrane generates voltages more than 20 V under ultrasound conditions, thereby promoting silver reduction. These materials have the potential to contribute significantly to the degradation of dyes and the purification of aqueous media, thereby facilitating the development of more efficient and sustainable water treatment methods.