Enhancement of piezoelectric energy-harvesting capacity of electrospun β-PVDF nanogenerators by adding GO and rGO

Abstract

In this paper, the electrical output voltage of highly piezoelectric properties of polyvinylidene fluoride (PVDF) was enhanced by using graphene oxide (GO) and reduced graphene oxide (RGO) additives. GO and RGO materials were synthesized by Hummer's method and their morphology, crystallinity and the effect of electrical outputs of β-PVDF were investigated. Different amounts of GO and RGO additives (0.4 and 0.8 wt%) embedded in PVDF polymeric material and electrospun nanofibres that show piezoelectric features were prepared by electrospinning process. All of the produced nanofibres were characterized in terms of structural and morphological properties by using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The piezoelectric nanogenerators prepared using electrospun β-PVDF mats with different amounts of GO and RGO were fabricated by sandwiching between two conductive aluminium plates. The same dimension (4 cm × 5 cm) of nanogenerators with a mat thickness of 50 µm was used to evaluate the electrical output data. All of the produced nanogenerators were examined for a finger-tapping action with a frequency of ~ 5 Hz. It was observed that the presence of 0.8 wt% of RGO increased the open-circuit voltage of β-PVDF for approximately nine times. This enhancement is associated with a certain and powerful interfacial interaction that occurs within the adsorption of molecular chain conformation of β-PVDF onto the GO and RGO surfaces. This new type of RGO-based nanogenerator could be of great advantage for a wide range of applications such as a self-charging power source, flexible and stretchable electronic devices, energy-harvesting devices, sensors and other electronic-based systems