Functionalized graphene oxide/polyvinylidene fluoride composite membrane acting as a triboelectric layer for hydropower energy harvesting

Abstract

Liquid-solid triboelectric nanogenerator (TENG) has received much attentionas a promising electricity generation mechanism for renewable energy sourcesand self-powered electronic devices. Thus, enhancing TENG performance is acritical issue to be concerned for both practical and industrial applications.Hence, in this study, for the first time, the liquid-solid TENG based onfunctionalized graphene oxide (F-GO) and polyvinylidene fluoride (PVDF)composite membranes containing various F-GO concentrations were fabricatedusing the blade coating process. The surface of GO nanosheets was functionalizedthrough covalent graft by using 1H,1H,2H,2H-perfluorooctyltriethoxysilane(FOTS). As indicated in FE-SEM images, the miscibility of the F-GO containingfluorine group in PVDF was effectively improved, which was created favorableconditions for PVDF crystallization and β phase configuration. Thus, the dielectricand polarization characteristics of the F-GO/PVDF membranes were greatlyimproved, eventuating in a rise in the output performance of F-GO/PVDF-basedTENG. As a consequence, the F-GO/PVDF TENG generates 0.14 mW of outputpower from a single water droplet, which is 7 times more than PVDF TENG and1.8 times higher than GO/PVDF TENG. It is proved the addition of functionalizedGO nanosheets in PVDF is very effective for hydropower energy harvesting basedon liquid-solid TENG.