An ultra high performance, lead-free Bi2WO6:P(VDF-TrFE)-based triboelectric nanogenerator for self-powered sensors and smart electronic applications

Obtaining sustainable, high output power supply from triboelectric nanogenerators still remains a major issue that restricts their widespread use in self-powered electronic applications. In this work, an ultra-high performance, non-toxic, flexible triboelectric nanogenerator based on bismuth tungstate (Bi₂WO₆):polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE)) is fabricated. A hydrothermal technique is used to synthesize highly crystalline Bi₂WO₆ nanoparticles that are then incorporated inside the P(VDF-TrFE) matrix nanofiber mat using electrospinning over an aluminum-coated PET substrate to yield a nanogenerator with a device configuration of Cu-coated PET/(Bi₂WO₆:P(PVDF-TrFE)) nanofiber mat/Al-coated PET. The highly crystalline nature of the biconcave shaped Bi₂WO₆ nanoparticles and β - P(VDF-TrFE) is confirmed by X-ray powder diffraction (XRD) and Raman spectroscopic techniques. The dielectric constant of the Bi₂WO₆:P(PVDF-TrFE) nanofiber mat was studied and a high dielectric constant of 44 was observed. The as-fabricated nanogenerator delivers a very high output voltage (open circuit) of 205 V and current density (short circuit) of 11.91 mA m^-2 at ∼0.15 kgf without any electric poling, which is higher than all the prior reports in this field. The fabricated nanogenerator possesses very high output stability and ultra-sensitivity with a swift response time of 60 ms. This outstanding performance of the nanogenerator can be ascribed to the synergistic combination of the β-phase P(VDF-TrFE) polymer and non-centrosymmetric nature of Bi₂WO₆ nanoparticles. Furthermore, a Bi₂WO₆-based pH sensor is driven by the energy obtained from the as-fabricated nanogenerator and the real time demonstration of the nanogenerator powering a calculator is also demonstrated. The strategy outlined here presents a cost-effective, high performance alternative for driving various portable bio-compatible self-powered electronic devices.