Sponge-Templated Macroporous Graphene Network for Piezoelectric ZnO Nanogenerator.
We report a simple approach to fabricate zinc oxide (ZnO) nanowire based electricity generators on three-dimensional (3D) graphene networks by utilizing a commercial polyurethane (PU) sponge as a structural template. Here, a 3D network of graphene oxide is deposited from solution on the template and then is chemically reduced. Following steps of ZnO nanowire growth, polydimethylsiloxane (PDMS) backfilling and electrode lamination completes the fabrication processes. When compared to conventional generators with 2D planar geometry, the sponge template provides a 3D structure that has a potential to increase power density per unit area. The modified one-pot ZnO synthesis method allows the whole process to be inexpensive and environmentally benign. The nanogenerator yields an open circuit voltage of ∼0.5 V and short circuit current density of ∼2 μA/cm(2), while the output was found to be consistent after ∼3000 cycles. Finite element analysis of stress distribution showed that external stress is concentrated to deform ZnO nanowires by orders of magnitude compared to surrounding PU and PDMS, in agreement with our experiment. It is shown that the backfilled PDMS plays a crucial role for the stress concentration, which leads to an efficient electricity generation.
Department of Chemical and Materials Engineering, and ‡Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2V4, Canada.
Xinda
X
Li
Department of Chemical and Materials Engineering, and ‡Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2V4, Canada.
Yi
Y
Chen
Department of Chemical and Materials Engineering, and ‡Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2V4, Canada.
Amit
A
Kumar
Department of Chemical and Materials Engineering, and ‡Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2V4, Canada.
Ahmed
A
Mahmoud
Department of Chemical and Materials Engineering, and ‡Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2V4, Canada.
John A
JA
Nychka
Department of Chemical and Materials Engineering, and ‡Department of Chemistry, University of Alberta , Edmonton, Alberta T6G 2V4, Canada.
Hyun-Joong
HJ
Chung
D000818:Animals; D004560:Electricity; D020342:Finite Element Analysis; D006108:Graphite / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation*; D011161:Porifera / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
D006108:Graphite; D015034:Zinc Oxide
hydrothermal synthesis; piezoelectric nanogenerator; reduced graphene oxide; sponge-templated macroporous network; zinc oxide nanowire