Flexible Piezoelectric Nanogenerator Based on a Poly(vinylidene fluoride)-Ti3C2 MXene Film for Underwater Energy Harvesting

The goal of energy harvesting is to create self-powered devices that can operate without the need for batteries or external power sources. This research intends to synthesize, characterize, and develop a flexible piezoelectric polymer composite device of poly(vinylidene fluoride) (PVDF) and Ti3C2 using a simple solvent-casting approach without an external poling procedure. Nanocomposites of PVDF with different concentrations of MXene (0.2, 0.8, 1, and 2 wt %) are prepared by the solvent-casting method using DMF as a solvent. Addition of Ti3C2 nanosheets into the polymer matrix has enhanced the beta phase content in PVDF. PVDF added with 1 wt % MXene exhibited the highest beta phase percentage as well as improved piezoelectric properties. Because MXene is distributed evenly in the PVDF matrix, it improves the beta phase of PVDF while decreasing the undesirable alpha phase configuration. According to the data obtained from dynamic contact electrostatic force microscopy, 1 wt % MXene-incorporated PVDF has a greater voltage output than other PVDF-MXene compositions. The ATR-IR spectrum reveals that the beta phase has been improved. A piezoelectric nanogenerator was fabricated with the composition of PVDF-1 wt % MXene. The device is tested by finger tapping which produces an electrical output of 5 V. The underwater energy-harvesting experiments were performed with different water flow rates from 0 to 3 m/s. The output voltage increased with water flow rate to a maximum peak-to-peak voltage of 21 V at a water flow rate of 3 m/s with a short-circuit current of 0.9 mu A. The device can be used to power underwater sensor networks.