Charge-trapping-blocking layer for enhanced triboelectric nanogenerators

The paramount parameters to determine the electrical output of triboelectric nanogenerator (TENG) are the surface triboelectric charges and the electrostatic induced transferred charges between triboelectric layer and electrode. However, diffusion of surface charge into the triboelectric layer reduces the surface charge density and thus weakens the electrostatic induction effect. In this work, we present a multifunctional layered TENG (ML-TENG) with an addition of reduced graphene oxide and Ag nanoparticles hybrid layer between a PVDF membrane triboelectric layer and bottom Al electrode to trap and block the interfacial charges. The output performance of ML-TENGs significantly yields 50 μC m−2 in charge density, which is improved by 500% compared with that of a traditional TENG. The surface potential of the PVDF membrane before triboelectrification drops with the insertion of the rGO-AgNPs hybrid layer, demonstrating the larger triboelectric potential difference and a better output performance. The trapping effect of rGO caused by sp2-hybrid structured carbon-atom coupled with the enhanced polarization effect by AgNPs to prevent interfacial charges from diffusing and drifting, providing efficient enhancements in TENG output. The output peak power from the TENG with a rGO-AgNPs hybrid layer reaches approximately 5.4 mW, which is 67.5 times that of a pristine TENG. Finally, the mechanism of the rGO-AgNPs layer working as the charge-trapping-blocking sites has been investigated and elaborated. It is anticipated to offer a new insight to the material science and device structure design for improving the performance of triboelectric devices.