High Performance Piezoelectric Nanogenerators Based on Electrospun ZnO Nanorods/Poly(vinylidene fluoride) Composite Membranes

A novel flexible zinc oxide/poly­(vinylidene fluoride) (ZnO/PVDF) nanocomposite was prepared by electrospinning for fabricating a piezoelectric nanogenerator (PNG). The ZnO nanoparticles (NPs) and nanorods (NRs) were used as nanofillers of piezoelectric PVDF to prepare fibrous nanocomposite membranes. It has been found that the addition of piezoelectric ZnO NPs and NRs can improve the overall performance of the PNGs fabricated with the electrospun membranes. A large electrical throughput (open circuit voltage ∼85 V and short circuit current ∼2.2 μA) from the ZnO NR/PVDF fiber membrane-based PNG (ZR-PNG) indicates that ZnO NRs are effective functional fillers for PVDF. The high aspect ratio and flexibility characteristics of ZnO NRs were found to be highly beneficial for improving the piezoelectric properties of the nanocomposites. ZnO NRs act as nucleating agents of β-phase PVDF, and ZnO NRs can also produce piezoelectric charges when they deform with the composite fibrous membrane. It has been concluded that the obvious synergistic effects between the piezoelectric nanofillers and electroactive β-crystals of PVDF in the ZnO NRs/PVDF composites are useful for the construction of the high-performance flexible PNG. In addition, the fabricated ZR-PNG can light up commercial light emitting diodes (40 white, 36 blue) and charge the capacitors in a very short time (3 V is accomplished in 25 s), which indicates the potential of the ZR-PNG for portable, wearable, flexible, or self-powered electronic devices.