Self-Poled Graphene Quantum Dots-Reinforced PVDF-HFP Nanocomposite Based Flexible Triboelectric Nanogenerator

Here, we have synthesized crystalline graphene quantum dots reinforced polyvinylidene fluoride-co tetrafluoroethylene (PVDF-HFP)-GQDs nanocomposite using a low-cost solution casting method. The X-Ray diffraction confirmed structural and self-poled β-phase in the PVDF-HFP nanocomposite and Fourier transform infrared spectroscopy technique. HR-TEM analysis reveals the formation of crystalline nature and size of the GQDs (diameter 5–10 nm). Due to the local polarization and self-poling effect, the β phase in the PVDF-HFP composite film is significantly increased from 68 to 78.3%. A triboelectric flexible nanogenerator device was also fabricated using the pristine and GQDs-reinforced PVDF-HFP nanocomposite film to harvest mechanical energy. The fabricated device exhibited a very high output voltage of about 15 V even under small vertical pressure and without external electrical poling. Almost, a 3-fold enhancement in the output voltage is observed due to the reinforcement of the GQDs inside the PVDF-HFP matrix. The dielectric constant of the pristine and GQD-reinforced nanocomposite exhibited a high dielectric constant of 5 and 11 at a low frequency of 200 Hz. This paper reveals the novel approach not only to improve the β-phase but also to fabricate high-performance self-poled PVDF-HFP-based triboelectric nanogenerators to design self-powered biocompatible nanosensors and nanosystems devices.