High-performance piezoelectric nanogenerators based on hierarchical ZnO@CF/PVDF composite film for self-powered meteorological sensor

Abstract

A high-performance piezoelectric sensor was fabricated for the real-time monitoring of meteorological wind and rainfall. A vertically aligned zinc oxide nanowires (ZnO NWs)@chopped short carbon fiber (CF)/poly(vinylidenefluoride) (PVDF) composite piezoelectric film was prepared by homogeneously distributing nail-raked ZnO@CF in a PVDF matrix by a hydrothermal method and a simple spin-coating method. The crystal structure and morphology were characterized. Vertically aligned and uniform arrays of hexagonal ZnO NWs were grown on the CF surface. The effects of the content of incorporated nail-raked ZnO@CF on the mechanical and electrical performance of ZnO@CF/PVDF were studied systematically. The maximum tensile strength of the ZnO@CF/PVDF composite film reached a value of 77.4 MPa with a content of 4.0 wt% of ZnO@CF. The output voltage and current of a ZnO@CF/PVDF composite film PNG also achieved maximum values of 14.91 V and 1.25 μA with a composite of the same ZnO@CF content. The maximum output power of the ZnO@CF/PVDF composite film PNG is about 7.9 μW with an external load of 10 MΩ. The ZnO@CF/PVDF composite film PNG could charge a capacitor and could instantly drive small electronic devices when the capacitor discharged, and the ZnO@CF/PVDF composite PNG could distinguish wind speed or the falling frequency of water drops. Besides, its excellent washability, durability for over 50 000 cycles and stability after 12 months mean the as-prepared ZnO@CF/PVDF composite film could possibly be used as a meteorological sensor for the real-time monitoring of meteorological conditions for self-driving automobiles.