Coupling photocatalysis and piezocatalysis in PVDF/ZnO nanofiber composites for efficient dye degradation

The development of advanced catalytic materials for environmental applications remains a critical challenge due to the limitations of conventional photocatalysis, such as low charge separation efficiency and dependence on external light sources. In this study, we present the synthesis and investigation of electrospun polyvinylidene fluoride (PVDF) nanofibers modified with zinc oxide (ZnO) nanoparticles for enhanced photocatalytic, piezocatalytic, and piezophotocatalytic activity. The morphology and structural properties of the composite material were analyzed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). The results show that the incorporation of ZnO reduces the average fiber diameter by 3.3 times and decreases the β-phase fraction from 87.3% to 71.6% due to nanoparticle agglomeration. The catalytic performance of PVDF/ZnO was evaluated in the degradation of methylene blue (MB) under different conditions: photocatalysis (71%), piezocatalysis (76%), and piezophotocatalysis (91%) within 60 minutes. Additionally, the membrane generated an average open-circuit voltage of 140 mV under mechanical stirring, demonstrating its ability to convert mechanical energy into electrical energy. These findings highlight the potential of PVDF/ZnO nanocomposites as multifunctional materials for sustainable catalytic applications and energy harvesting.