Effect of ZnO nearly spherical nanoparticles on piezoelectric response and fiber size of PVDF electrospun nanofibers

This study focused on fabrication of lead-free PVDF electrospun nanofibers with enhanced piezoelectric properties and reduced fiber diameter, achieved by incorporating ZnO nearly spherical nanoparticles (NSNs). Incorporation of ZnO NSNs at different concentrations (0–15 wt.%) progressively decreases fiber diameter from 705 nm to 200 nm and increases β-phase content from 58.90% to 90.07%, as confirmed by FE-SEM and FTIR analyses. XRD results also revealed that the addition of ZnO NSNs enhances the electroactive β-phase content and crystallinity of PVDF nanofibers, confirming successful ZnO incorporation. These structural enhancements transformed into a significant rise in piezoelectric performance, which was evaluated by measuring the generated output voltage by the nanofibers under applied pressure using a custom-built device, revealing a significant improvement reaching 1100 µV at 15 wt.% ZnO NSNs, over a 200% increase compared to pristine PVDF. The enhancements are attributed to inherent piezoelectricity of ZnO NSNs and their ability to modulate the dielectric properties of the solution, promoting enhanced jet stretching and β-phase nucleation during electrospinning. The resulting nanofibers demonstrate promising potential for applications in energy harvesting and wearable electronics.