Dopamine treated SnO₂/PVDF composite films for hybrid mechanical energy harvester

Combining the piezoelectric and triboelectric effects into a single device called hybrid nanogenerator (HNG) is a key discovery to overcome the drawback of low electrical output piezo/triboelectric nanogenerators. This work elaborates detailed electrical performance investigation on dopamine treated tin oxide (DA@SnO₂) nanoparticles (NPs) impregnated polyvinylidene fluoride (PVDF)-based HNG. The mixing of SnO₂ NPs inside the PVDF matrix enhances the β phase of the composite film and the electrical performance of the respective HNG. The coating of DA on SnO₂ NPs works as a binder between SnO₂ NPs and PVDF polymer by removing the defects in the SnO₂/PVDF composite film. Also, the presence of carbon in DA increases electron generation inside the composite film, which further enhances the electrical output of HNG. With this effect, the fabricated DA@SnO₂/PVDF-based HNG produced maximum electrical outputs of 62 V, 1.55 μA, and 17.9 μC/m² which were considerably higher than those of the SnO₂/PVDF-based HNG. Finally, the DA@SnO₂/PVDF-based HNG was tested for different operational parameters and used to charge commercially available capacitors and power up small-scale electronics. The proposed HNG provides an excellent energy harvesting capability and can be employed to harvest energy from abundantly available mechanical movements.