Poly(dimethylsiloxane)/ZnO Nanoflakes/Three-Dimensional Graphene Heterostructures for High-Performance Flexible Energy Harvesters with Simultaneous Piezoelectric and Triboelectric Generation

Herein,
we report the successful synthesis of poly­(dimethylsiloxane)/ZnO
nanoflakes/three-dimensional graphene (PDMS/ZnO NFs/3D Gr) heterostructures
using Ni foams as the template substrate via a facile route, while
adapting a rational material design for a high-performance energy-harvester
application. The PDMS/ZnO NFs/3D Gr heterostructure-based hybrid energy
harvester simultaneously exploits the piezoelectric effect and triboelectrification
and shows peak-to-peak output voltages up to 122 V and peak-to-peak
current densities up to 51 μA cm–2, resulting
in an ultrahigh power density of 6.22 mW cm–2. Furthermore,
we have evaluated the performance of the PDMS/ZnO NFs/3D Gr heterostructure-based
hybrid energy harvester by demonstrating its capacity to instantaneously
power up 68 commercially available light-emitting diodes without the
need for an additional energy-storage device. The excellent performance
of these energy harvesters suggests that PDMS/ZnO NFs/3D Gr heterostructures
present a viable strategy for the development of high-performance,
flexible, wearable energy-harvesting devices.