Significant triboelectric enhancement using interfacial piezoelectric ZnO nanosheet layer

Abstract

Significant triboelectric enhancement using interfacial piezoelectric ZnO nanosheet layer, Nano Energy, http://dx.doi.org/10. 1016/j.nanoen.2017.08.053 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Utilising an interfacial piezoelectric ZnO nanosheet layer, a significant enhancement in the power density is reported for the triboelectric nanogenerators (TENG) based on phase inversion membranes of polyvinylidene fluoride (PVDF) and polyamide-6 (PA6). At an applied force of 80 N, the TENG device incorporating electrochemically deposited ZnO nanosheets produces an output voltage of ~625 V and a current density of ~40 mAm -2 (corresponding a charge density of 100.6 Cm -2 ), respectively; significantly higher than ~310 V and ~10 mAm -2 (corresponding a charge density of 77.45 Cm -2 ) for the pristine TENG device. The enhancement in the surface charge density provided by the interfacial piezoelectric ZnO layer is also reflected in the high piezoelectric coefficient d 33 (-74 pmV -1 ) as compared to the pristine fluoropolymer membranes (-50 pmV -1 ). For tribo-negative membranes incorporating the interfacial ZnO layer, piezoelectric force microscopy measurements further show enhanced domain size which can be attributed to the interfacial dipole-dipole interaction with the ferroelectric polarization of PVDF, which promotes the alignment with the polar axis of ZnO. Under compressive stress, the piezoelectric potential thus produced in the ZnO nanosheets provides charge injection on to the surface of ZnSnO 3 -PVDF membrane, improving the charge density, which in-turn significantly enhances the power density from 0.11 to ~1.8 W/m 2 . The TENG devices thus fabricated using a facile electrochemical deposition and phase inversion technique show enhanced output power without the need for high electric field poling or external charge injection process by relying on coupling of triboelectric and piezoelectric effects.

Significantly Enhanced Performance of Triboelectric Nanogenerator by Incorporating BaTiO3 Nanoparticles in Poly(vinylidene fluoride) Film

“…Current development in this research field has been mainly focusing on enhancing the output performance of TENGs. Many methods, technologies and device structures have been developed to enhance the performance of TENGs such as modulating surface roughness and nanoparticle dispersion to drastically increase the effective surface areas of contact materials; using ferroelectric and piezoelectric tribomaterials such as poly(vinylidene fluoride) (PVDF) and ZnO nanosheets to increase the surface charge density through polarization. Li et al developed an effective surface modification method on the PET film, which realizes significant enhancement of triboelectric charge density for high‐performance TENGs.…”

Conjunction of triboelectric nanogenerator with induction coils as wireless power sources and self-powered wireless sensors

“…The synthesis of PA6 films followed the phase-inversion process developed by Soin et al 46 . The doped solution was prepared using a 20 wt% solution in the solvent formic acid by continuously stirring at ~70 °C for 3 h. The prepared solution was deposited on a silicon wafer via a spin-coating process: initial spinning at 10 rpm for 5 s, and followed by 2000 rpm for 20 s. The coated substrate was then immersed immediately in an antisolvent bath kept at the desired quenching temperature of ~20 °C.…”

Toward High‐Performance Triboelectric Nanogenerators by Engineering Interfaces at the Nanoscale: Looking into the Future Research Roadmap

“…An incorporated interfacial ZnO nanosheet layer Reproduced with permission. [ 80 ] Copyright 2017, Elsevier.…”

“…This enhancement facilitates the charge injection by a piezoelectric interlayer onto the surface of a ZnSnO 3 ‐PVDF membrane, and the charge density increases from 77.45 µC m −2 (without an interfacial ZnO nanosheet layer) to 100.66 µC m −2 , which in turn improves significantly the power density from 0.11 to ≈1.8 W m −2 . [ 80 ] It should be noted that in another application, the addition of semiconductive ZnO nano/hierarchical particles into insulating dielectrics, e.g., polyethylene at very low loading amounts, suppresses the charging currents due to trapping of charge carriers at the interface, where the insulating properties were enhanced. [ 1,100,109 ] However, the same ZnO particles (with controlled facets) on another application, i.e., photocatalyst micromotors, have shown improved charge transfer at the interface layer with noble metals and both photocatalytic and motion were enhanced.…”