Sponge-Templated Macroporous Graphene Network for Piezoelectric ZnO Nanogenerator

Abstract

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.

Fabrication of silver-doped zinc oxide nanorods piezoelectric nanogenerator on cotton fabric to utilize and optimize the charging system

“…In addition, there has been rapid progress on fabricating stretchable or flexible PENGs based on ZnO nanorods. The frequently used flexible substrates are sponge, 23 flexible plastic, 24 polyethylene terephthalate, [25][26][27] paper, [28][29][30] and textile fabric. 31 Among these, textile materials possess mechanical flexibility, low cost, lightweight, and used for integration into different areas such as clothing accessories.…”

Three‐Dimensional Hierarchically Mesoporous ZnCo2O4 Nanowires Grown on Graphene/Sponge Foam for High‐Performance, Flexible, All‐Solid‐State Supercapacitors

“…[9] Surface modification of commercial sponges with rGOs and/or carbonn anotubes has been realized by using noncovalent modification methodst hat involve as imple dip-coating process. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Commercial spongesc oatedw ith rGOs may have important applicationsi nl ow-cost,f lexible, energy-storage devices due to properties of high surface area, 3D open channels, flexibility,l ightweight, great hardness, and high conductivity. Use of as ponge architecture can expandt he effective contact area between active materials and electrolytes, as well as reinforce interfacial contact between the current collector and active materials, thereby considerably improving ion and electron transport, leadingt om uch improved electrochemical activitiest hat fill in the 3D open-pore network.…”

Optimization, characterization and evaluation of ZnO/polyvinylidene fluoride nanocomposites for orthopedic applications: improved antibacterial ability and promoted osteoblast growth

“…As is well-known, the piezoelectric constant of a polymer is usually lower than inorganic materials (Bar-Cohen & Zhang, 2008 ) which limits the use of polymers as piezoelectric mimicking orthopedic materials. However, a high piezoelectric simulation can be provided by a composite of PVDF and nanometer ZnO, thus, a ZnO/PVDF composite fiber membrane may possess good biocompatibility (Sultana et al., 2015 ), piezoelectricity, and antibacterial protpeties suitable for orthopedic applications (Li et al., 2015 ).…”