Hierarchical PbZr x Ti1–x O3 Nanowires for Vibrational Energy

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Hierarchical PbZrxTi1-xO3 nanowires for vibrational energy harvesting Xing Zhang, Jingfan Chen, and Ya Wang ACS Appl. Nano Mater., Just Accepted Manuscript • DOI: 10.1021/acsanm.7b00317 • Publication Date (Web): 27 Mar 2018 Downloaded from http://pubs.acs.org on March 28, 2018

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ACS Applied Nano Materials

Hierarchical PbZrxTi1-xO3 Nanowires for Vibrational Energy Harvesting Xing Zhang, *† Jingfan Chen, † and Ya Wang*† †

Department of Mechanical Engineering, Stony Brook University, Stony Brook, New York, 11794-2300, United States

*Corresponding authors: Tel: +1-631–632–8322; Dr. Xing Zhang, E-mail: [email protected]; Dr. Ya Wang, E-mail: [email protected]

Notes The authors declare no competing financial interest.

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ABSTRACT

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Perovskite piezoelectric material nanostructures have gained immense interest in

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the energy harvesting community due to their ability of converting mechanical energy

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into electric power in a much more efficient manner. In this paper, we first

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successfully synthesized PbZrxTi1-xO3 (PZT) nanowires with unique hierarchical

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nanostructures of ~ 100 nm in diameter and 6 µm long, by using a facile hydrothermal

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process. Then a unimorph cantilever energy harvester was fabricated by bonding a

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mixed hierarchical PZT nanowires with polydimethylsiloxane (PDMS) polymer

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matrix to a brass substrate. The measured open-circuit voltage from this harvester was

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2.7 V at its fundamental resonance (25.2 Hz) under 100 mg root mean square (RMS)

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acceleration input, and the measured power density was 51.8 µW cm-3 with an

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optimal load resistance of 2 MΩ, which is approximately 8 times larger than that of

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the commercial BaTiO3 nanowires energy harvester on the same scale, but driven by a

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much higher acceleration level.

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KEYWORDS: PbZrxTi1-xO3 nanowires, hierarchical nanostructure, open-circuit

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voltage, power density, vibrational energy harvesting

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INTRODUCTION

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Perovskite piezoelectric materials have attracted considerable attention because they

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can generate electrical power from ambient vibrational energy more efficiently,1, 2

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such as from engine vibrations,3 direct human walking motion,4,

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air-flowing,6-9 and even tiny biomechanical movements from muscles/organs,10 which

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could lead to a range of important potential applications for powering sensors,

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actuators, implants, etc. The energy conversion efficiency of piezoelectric devices

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largely depends on the piezoelectric coupling coefficient of nanomaterials,11 which

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significantly relies on the structures formed through the synthesis processes,12 the

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crystalline orientation,13 and the doping elements into the host lattice.14 Therefore, the

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synthesis approaches should be extensive conducted for achieving high-power-density

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energy harvesting. These approaches can be systematically investigated by adjusting

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the reaction conditions for exploiting their full potential in nanotechnology

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applications.

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gentle

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Energy harvesting properties have been successfully demonstrated in the

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literature on many high-efficient piezoelectric materials, such as ZnO,15-17 MoS2,18

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NKN,19-22 lead zirconium titanate (PZT),23-29 CdTe,30 BaTiO3,31,

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BiFeO3,35, 36 and TMCMMnCl337. Among these piezoelectric materials, PZT ceramics

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is the most cost-effective candidate for its perovskite nanostructure, high

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electromechanical coupling coefficient, high Curie temperature, spontaneous

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polarization and inexpensive fabrication process.37 Thus, it has been widely used in 3 ACS Paragon Plus Environment

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PMN-PT,33,

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many commercial products for powering high performance sensors and actuators.38, 39

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However, it is well known that PZT ceramics has the deficiency of low flexibility,

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high fragility and brittleness, which makes it difficult to be applied in flexible or

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wearable devices.40 Polydimethylsiloxane (PDMS) with the virtues of elasticity,

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thermal stability, and biocompatibility has been widely employed as a supporting

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medium in various flexible devices.41, 42 Therefore, embedding the PZT nanoparticles

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into PDMS matrix to form a readily flexible and tailorable device, may overcome

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such a restriction.

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For nanoscale piezoelectric materials, several typical piezoelectric nanostructures

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have been designed for efficiently powering small electronics. For example, vertically

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aligned BaTiO3 nanowire array energy harvester can provide an average power

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density of approximately 6.27 µW cm-3 from 1 g acceleration, which is 16 times

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higher than that of vertically aligned ZnO nanowire arrays from the same acceleration

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input.17 Recently, hierarchical PMN−PT nanocomposites34 can output the maximum

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voltage of 7.8 V, which is over 2 times larger than that of the BaTiO3 nanocomposite

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harvester

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novel and more sophisticated perovskite structures piezoelectric nanocomposite

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containing unique PZT nanostructures would have great potential for high-power

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nanogenerators and large-output signal with flexibility and low cost. Such as

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hierarchical PZT nanowires, has not been reported due to the complexity of synthesis

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methods. Therefore, the development of rational synthesized routes to assemble

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nanoscale PZT nanowires into hierarchical structures in a cost-effective manner for

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(3.2 V) and that of the NaNbO3 nanoharvester44 (3.2 V). However, the

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achieving high-efficient energy harvesting is desirable and significant, which would

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greatly promote their applications in nanodevices.

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Herein, we reported a simple and facile synthesis approach to build PZT

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nanowires with unique hierarchical nanostructures under hydrothermal conditions

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using sodium titanate nanowires as the source. The unimorph cantilever harvesting

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device was fabricated by bonding mixed hierarchical PZT nanowires with PDMS

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matrix to a brass substrate. This piezoelectric energy harvester produced much higher

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output voltage and power than other reported piezoelectric nanocomposites. This is

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potentially a

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micro/nanodevices.

key step in developing sustainable energy technology for

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EXPERIMENTAL SECTION

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Reagents. All the chemicals and materials used in this work include: Titanium (IV)

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butioxide (TBOT, Sigma Aldrich, St. Louis, MO), zirconium (IV) oxychloride

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(ZrOCl2·8H2O, Sigma Aldrich, St. Louis, MO), ethanol (EtOH, Sigma Aldrich, St.

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Louis, MO), ammonia solution (NH3, 2.0 M in ethanol, Sigma Aldrich, St. Louis,

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MO), potassium hydroxide (KOH, Sigma Aldrich, St. Louis, MO), lead (Ⅱ) nitrate

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(Pb(NO3)2, Sigma Aldrich, St. Louis, MO), and acetic acid (Sigma Aldrich, St. Louis,

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MO), were all analytical-grade purity and used as received without further

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purification. Distilled water was used in the preparation of all aqueous solutions.

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Synthesis of potassium zirconium titanate nanowires as a precursor. The

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potassium zirconium titanate nanofibers were synthesized as zirconium and titanium

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sources for the hydrothermal synthesis of PbZrxTi1-xO3. Firstly, Ti(C4H9O)4 (1.354

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mL) and ZrOCl2·8H2O (2.08 mmol) were dissolved into 15 mL ethanol under

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continuous magnetic stirring condition, and the ratios of Zr: Ti approximately is 3.5:

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6.5, then 5 mL ammonia solution (2.0 M in ethanol) added into the above mixture

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solution under continuous magnetic stirring. Followed by the addition of KOH (28 g)

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pellets and H2O (50-mL), and a white suspension was formed immediately. The white

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suspension was transferred into a 100-mL autoclave with a Teflon linear, which was

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heated at 200 °C for 16 h, and then naturally cooled to ambient temperature. The

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resulting white solid powders were collected by centrifugation and washed with

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distilled water and absolute alcohol for several times to remove residual ions. The

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final products were then dried at 80 °C for 8 h for the next step using for further

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characterization.

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Synthesis of lead zirconium titanate (PZT). In this step, potassium zirconium

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titanate precursor (0.2864 g) was dispersed in 15 mL distilled water and sonicated for

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30 min, followed by adding Pb(NO3)2 (4.0 mmol), then KOH pellets (15 g) were

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added directly and stirred for 15 min, and finally 50 mL H2O was poured into the

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above mixture solution. The final mixture was transferred into a 100-mL Teflon lined

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stainless steel autoclave. The reactor was heated in an oven at 200 °C for 24 h. After

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the hydrothermal reaction was completed, the reaction products were sequentially

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washed with a diluted acetic acid aqueous solution, water and ethanol for several 6 ACS Paragon Plus Environment

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times to remove residual ions and centrifugation collected. The final product was then

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dried at room temperature for 24 h.

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Physicochemical characterization of the samples. The X-Ray diffraction

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(XRD, Rigaku Ultima III) was conducted to confirm the crystallinity of hierarchical

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PZT nanowires. The scanning electron microscopy (SEM) was characterized with a

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Crossbeam 340 microscope (Zeiss, Oberkochen, Germany). In addition, energy

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dispersive X-ray spectroscopy (EDS) was performed with an INCA Energy 350

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AzTec Advanced system using a silicon drift detector (SDD) (Oxford Instruments,

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Abingdon, UK) for the determination of element stoichiometry.

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Fabrication of PZT-PDMS nanocomposite unimorph. The nanocomposite was

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made by mixing PZT nano-powder into the PDMS (SYLGARD, 184 silicone

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elastomer kit) matrix via sonication for 30 min in order to expel the dissolved air

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formation bubbles. The weight percentage of PZT in PDMS was approximately

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40%.45 The mixture was spin-coated on an acrylic plate and then transferred into a Cu

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foil substrate. The final geometry of the unimorph cantilever beam is 4 cm (L) × 0.7

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cm (W) × 0.004 cm (H), (the photo representation of the unimorph harvester can be

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found in the supplementary information (SI) Figure S1). After curing in the oven at

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120 °C for 6 hours, silver paste was covered on the top of the nanocomposite film to

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function as the top electrode. Then, the resulting nanocomposite was poled at 1 kV for

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6 hours (TREK model 2220) at room temperature.

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Electrical measurement. An electromagnetic shaker (APS-113, APS Dynamics

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Inc.) was used to generate mechanical vibration by accelerating the clamped end of 7 ACS Paragon Plus Environment

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the cantilever beam. The mechanical input energy was measured by mounting a shear

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accelerometer (PCB 333B32) on the root of the energy harvester. Power density

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measurement was performed across a series of load resistances from 0 to 10 MΩ

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provided by a resistance box. The electrical output signals were recorded by using an

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oscilloscope (RIGOL MSO1104). The photo representation of experimental setup,

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data acquisition, and testing processes has been provided in the SI (Figure S2).

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RESULTS AND DISCUSSION

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Fabrication and characterization of the PZT nanostructures. Figure 1 shows the

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XRD pattern of the sample hydrothermally synthesized with the potassium zirconium

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titanate nanowires (see ESI Figure S3) as Zr and Ti sources. All diffraction peaks can

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be easily indexed to the tetragonal PZT, corresponding well with the reported data of

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JCPDS No. 06-0452. The strong and sharp reflection peaks indicate that the

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as-prepared PZT product is well crystallized.

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Figure 2 shows typical SEM images of the obtained PZT sample by the

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hydrothermal method. Figure 2a shows that the product consisting of a large quantity

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of hierarchical structures. Figure 2b is a higher magnification SEM image of a

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randomly selected area. The sample images show a three-dimensional hierarchical

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structure with individual nanowires extending from cube faces directions. The length

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of some nanowires is up to 6 µm, and the length of each individual nanowire varies

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with the similar diameter of approximately 100 nm. The composition of hierarchical 8 ACS Paragon Plus Environment

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PZT nanowires was determined by scanning electron microscopy-energy dispersive

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X-ray spectroscopy. As shown in Figure S4, it clearly indicates that the single

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hierarchical PZT nanowire is composited of Pb, Zr and Ti elements.

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Investigation of the influence factors for the formation of hierarchical PZT

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nanowires. The amount of Pb(NO3)2 is critical to the configuration of the synthesized

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assembly, and thus its ratio influence on the nanostructure of the final product is

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investigated in detail in this experiment. Figure 3 shows the SEM images of the

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products synthesized with different amounts of Pb(NO3)2. When 3 mmol of Pb(NO3)2

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is added as a Pb2+ source, PZT assembled with long nanorods appeared in the product,

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as shown in Figure 3a, b, and no particles were produced. The change of morphology

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is observed by further increasing the amount of Pb(NO3)2 in the system, and Figure 3c,

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d give the SEM image of the product obtained by adding 5 mmol of Pb(NO3)2. The

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cube PZT can be obtained with the size of 2 µm.

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To get insight into the Zr and Ti ions ratio effect on the evolution of PZT

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nanostructures, a series of Zr and Ti ratios-dependent experiments were conducted.

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Figure 4 shows representative SEM images for the samples obtained with different Zr:

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Ti ratios. With no added Zr elements, the product of PbTiO3 consists of well-defined

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plate nanostructure with a rectangular outline and a side length of 500–3000 nm

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(Figure 4a), and the thickness of the nanoplates is approximately 200 nm (Figure 4b).

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When increasing the Zr: Ti ratio up to 1:9, the PZT sample shows the same nanoplate

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assembly but with much larger size of up to 10 µm (Figure 4c, d). It is very interesting

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to notice that when the Zr: Ti ratio increases up to 2:8, the obtained PZT product 9 ACS Paragon Plus Environment

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displays cube-like nanostructures with the size of 2-5 µm (Figure 4e). Obviously, the

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surface of the cube-like structure is rugged, which is assembled by small nanoplates

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(Figure 4f). These results, indicate that the higher Zr concentration could be

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favourable for the formation of three-dimensional PZT nanocube structures.

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In addition, we also investigated the effect of reaction temperature on the sample

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morphology under the same Pb2+. As shown in Figure 5a, b, cube-like assemble with

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square rods of 400 nm diameter and 5 µm long was obtained at 170 °C. While

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increasing the reaction temperature to 185 °C, the surface square rods grow bigger

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with the size of ~6 µm long (Figure 5c, d). Figure 5d shows the broken square rods

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consisting of many nanorods, and some of the rods fuse together. When the

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temperature increases to 210 °C, we could find the cube-like morphology of our PZT

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product with many nanowires (Figure 5e, f). The results indicate that the surface of

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cube-like PZT nanostructure could be tuned by manipulating the synthetic reaction

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temperature.

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The energy harvesting performances of the PZT-PDMS nanocomposites.

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Figure 6 shows the schematic representation of the energy harvester device

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fabrication processes. First, an acrylic sheet is cleaned with deionized water and

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alcohol (Figure 6a). Next, the preparing the mixture solution of PZT nano-powder and

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the PDMS matrix with weight ratio 40: 60, then spin coat the hierarchical PZT

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nanowires and the PDMS mixture (Figure 6b). The detailed mixture preparation

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process is described in the Experimental section. Next, the composite thin film with

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hierarchical PZT nanowires is peeled off from the acrylic substrate (Figure 6c). It 10 ACS Paragon Plus Environment

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should be noted that the composite thin film can be easily detached from the acrylic

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substrate after curing enough time. Next, attach the composite thin film onto the brass

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(Cu) beam with PDMS before curing (Figure 6d). The composite film can be bonded

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tightly by curing the PDMS. Finally, the conductive silver epoxy is covered on the top

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side of the PZT-PDMS film (Figure 6e).

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To demonstrate sustainable power generation from synthesized hierarchical PZT

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nanowires, the energy harvester is subjected to a sinusoidal base acceleration

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generated by a permanent magnet shaker. The clamped boundary condition of the

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energy harvester device allows simple periodic vibration of the cantilever at its

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resonant frequencies. This vibration induces compressive and tensile stress on the

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hierarchical PZT nanowires thus generating charge by the direct piezoelectric effect,

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resulting in a potential difference between the two electrodes of the beam. The

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frequency-dependent open-circuit voltage output of the energy harvester device has

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been investigated, as shown in Figure 7a. Obviously, the open-circuit voltage

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increased with the exciting frequencies from 24.5 to 25.2 Hz based on 100 mg root

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mean square (RMS) acceleration and then decreased with the continuant increasing

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from 25.2 to 26.1 Hz. The results indicate that sinusoidal excitation at resonant

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frequency of 25.2 Hz yielded the highest peak to peak voltage ~2.7 V from 100 mg

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RMS acceleration input as shown in Figure 7b, which indicates the compressive and

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tensile stress is maximum under its resonant frequencies (25.2 Hz) when the

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amplitude up to maximum. The open-circuit voltage output of hierarchical PZT

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nanowires energy harvester at a range of RMS sinusoidal acceleration from 20 to 94 11 ACS Paragon Plus Environment

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mg is shown in Figure 7c. The open-circuit voltage output from the hierarchical PZT

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nanowires energy harvester increased with the increasing RMS acceleration. The

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higher voltage output is produced because the high dynamic input induces a higher

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alternating piezoelectric charge accumulation at the two electrodes. At this resonant

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frequency, the PZT-PDMS device was subjected to various accelerations thus

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producing the different bending strain states result in producing different output

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voltage. Therefore, the cantilever vibrating with maximum strain can generates

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maximum output voltage by increasing the amplitude of the sinusoidal acceleration at

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the resonant frequency. The hierarchical PZT nanowires also exhibits better

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performance than two-dimensional PbTiO3 nanoplates (Figure S5). The power output

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from the hierarchical PZT nanowires energy harvester is calculated by measuring the

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voltage, across several load resistors (RL), ranging from 0 to 10 MΩ. The power

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output from the hierarchical PZT-PDMS nanocomposite energy harvester increased

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rapidly as RL was increased up to 2 MΩ when a peak value of 0.58 µW is reached,

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and then reduced as RL was increased up to 10 MΩ. The peak power density across

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the optimal RL is calculated to be 51.8 µW cm-3 from 100 mg RMS base acceleration

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(Figure 7d). This power density is 8 times higher than that recorded from the BaTiO3

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based energy harvester (6.27 µW cm-3) driven by a higher base acceleration of 1.0 g

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RMS.32 It is noticed that hierarchical PZT nanowires have a higher power density than

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BaTiO3, because of the following advantages. Firstly, the PZT owns higher

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piezoelectric constants than that of the BaTiO3 and ZnO, which can effectively

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improve the voltage output, and the special hierarchical nanostructure always makes 12 ACS Paragon Plus Environment

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some nanowires of the bulk parallel to the two electrodes, which makes hierarchical

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PZT nanowires potentially have a higher effective length strain.34 Therefore, the

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significant performance improvement in the energy harvester device based on

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hierarchical PZT nanowires are largely attributed to both the higher piezoelectric

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constant and the unique hierarchical structure.

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CONCLUSIONS

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In summary, we have synthesized PZT nanowires with novel hierarchical

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nanostructures of ~100 nm in diameter and ~6 µm long, by using a facile

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hydrothermal process. We have fabricated a unimorph energy harvester by bonding

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hierarchical PZT nanowires with PDMS polymer mixture to a brass substrate. The

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peak output voltage from this energy harvester was 2.7 V at its fundamental resonance

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of 25.2 Hz, and the power density was 51.8 µW cm-3 with an optimal load resistance

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of 2 MΩ. This power density is 8 times higher than that recorded from the BaTiO3

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based energy harvester (6.27 µW cm-3) driven by a higher base acceleration RMS.

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This is a key step in developing sustainable energy harvesting technical for

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micro/nanodevices.

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ACKNOWLEDGEMENTS

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The authors thank the support by the US Office of Navy Research 13 ACS Paragon Plus Environment

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(N000141410230), and the Department of Energy ARPA-E (DOE-AR0000531) to

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this work. This research used resources from the Center for Functional Nanomaterials,

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which is a U.S. DOE Office of Science Facility, at the Brookhaven National

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Laboratory under Contract No. DE-SC0012704.

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Appendix A. Supplementary Data

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Supplementary data associated with this article can be found in the online version.

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REFERENCES

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(1)

Bowen, C.; Kim, H.; Weaver, P.; Dunn, S. Piezoelectric and Ferroelectric

271

Materials and Structures for Energy Harvesting Applications. Energy Environ.

272

Sci. 2014, 7, 25-44.

273

(2)

Zhang, Y.; Xie, M.; Adamaki, V.; Khanbareh, H.; Bowen, C. R. Control of

274

Electro-chemical Processes using Energy Harvesting Materials and Devices.

275

Chem. Soc. Rev. 2017, 46, 7757.

276

(3)

Chen, J.; Huang, Y.; Zhang, N.; Zou, H.; Liu, R.; Tao, C.; Fan, X.; Wang, Z. L.

277

Micro-cable Structured Textile for Simultaneously Harvesting Solar and

278

Mechanical Energy. Nature Energy 2016, 1, 16138.

279

(4)

Microsystems Applications. Meas.Sci. Technol. 2006, 17, R175-R195.

280 281

Beeby, S. P.; Tudor, M. J.; White, N. Energy Harvesting Vibration Sources for

(5)

Siddiqui, S.; Lee, H. B.; Kim, D. I.; Duy, L. T.; Hanif, A.; Lee, N. E. An 14 ACS Paragon Plus Environment

Page 14 of 29

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ACS Applied Nano Materials

282

Omnidirectionally Stretchable Piezoelectric Nanogenerator Based on Hybrid

283

Nanofibers and Carbon Electrodes for Multimodal Straining and Human

284

Kinematics Energy Harvesting. Adv. Energy Mater. 2018, 8.

285

(6)

Kitio Kwuimy, C.; Litak, G.; Borowiec, M.; Nataraj, C. Performance of a

286

Piezoelectric Energy Harvester Driven by Air Flow. Appl. Phys. Lett. 2012, 100,

287

024103.

288

(7)

Dias, J.; De Marqui Jr, C.; Erturk, A. Hybrid Piezoelectric-inductive Flow

289

energy Harvesting and Dimensionless Electroaeroelastic Analysis for Scaling.

290

Appl. Phys. Lett. 2013, 102, 044101.

291

(8)

Han, N.; Zhao, D.; Schluter, J. U.; Goh, E. S.; Zhao, H.; Jin, X. Performance

292

Evaluation of 3D Printed miniature Electromagnetic Energy harvesters Driven

293

by Air Flow. Appl. Energy 2016, 178, 672-680.

294

(9)

Zheng, L.; Cheng, G.; Chen, J.; Lin, L.; Wang, J.; Liu, Y.; Li, H.; Wang, Z. L. A

295

Hybridized Power Panel to Simultaneously Generate Electricity from Sunlight,

296

Raindrops, and Wind Around the Clock. Adv. Energy Mater. 2015, 5,

297

1501152-1501159.

298

(10) Amin Karami, M.; Inman, D. J. Powering Pacemakers from Heartbeat

299

Vibrations using Linear and Nonlinear Energy Harvesters. Appl. Phys. Lett.

300

2012, 100, 042901.

301

(11) Whiter, R. A.; Narayan, V.; Kar‐Narayan, S. A Scalable Nanogenerator Based on

302

Self‐Poled Piezoelectric Polymer Nanowires with High Energy Conversion

303

Efficiency. Adv. Energy Mater. 2014, 4, 1400519-1400525. 15 ACS Paragon Plus Environment

ACS Applied Nano Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

304

(12) Koka, A.; Zhou, Z.; Tang, H.; Sodano, H. A. Controlled Synthesis of Ultra-long

305

Vertically Aligned BaTiO3 Nanowire Arrays for Sensing and Energy Harvesting

306

Applications. Nanotechnology 2014, 25, 375603-375612.

307

(13) Yan, Y.; Zhou, J. E.; Maurya, D.; Wang, Y. U.; Priya, S. Giant Piezoelectric

308

Voltage Coefficient in Grain-oriented Modified PbTiO3 Material. Nature

309

Commun. 2016, 7, 13089.

310

(14) Zhang, M.H.; Wang, K.; Du, Y.J.; Dai, G.; Sun, W.; Li, G.; Hu, D.; Thong, H. C.;

311

Zhao, C.; Xi, X.Q. High and Temperature-Insensitive Piezoelectric Strain in

312

Alkali Niobate Lead-free Perovskite. J. Am. Chem. Soc. 2017, 139, 3889-3895.

313 314 315 316

(15) Wang, Z. L.; Song, J. Piezoelectric Nanogenerators Based on Zinc Oxide Nanowire Arrays. Science 2006, 312, 242-246. (16) Xu, S.; Qin, Y.; Xu, C.; Wei, Y.; Yang, R.; Wang, Z. L. Self-powered Nanowire Devices. Nature Nanotechnol. 2010, 5, 366-373.

317

(17) Malakooti, M. H.; Patterson, B. A.; Hwang, H.S.; Sodano, H. A. ZnO Nanowire

318

Interfaces for High Strength Multifunctional Composites with Embedded

319

Energy Harvesting. Energy Environ. Sci. 2016, 9, 634-643.

320

(18) Wu, W.; Wang, L.; Li, Y.; Zhang, F.; Lin, L.; Niu, S.; Chenet, D.; Zhang, X.;

321

Hao, Y.; Heinz, T. F. Piezoelectricity of Single-atomic-layer MoS2 for Energy

322

Conversion and Piezotronics. Nature 2014, 514, 470-474.

323

(19) Wu, J.; Xiao, D.; Zhu, J. Potassium–sodium Niobate Lead-free Piezoelectric

324

Materials: Past, Present, and Future of Phase Poundaries. Chem. Rev. 2015, 115,

325

2559-2595. 16 ACS Paragon Plus Environment

Page 16 of 29

Page 17 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Nano Materials

326 327

(20) Saito, Y.; Takao, H.; Tani, T.; Nonoyama, T.; Takatori, K.; Homma, T.; Nagaya, T.; Nakamura, M. Lead-free Piezoceramics. Nature 2004, 432, 84-87.

328

(21) Kang, M.G.; Oh, S.M.; Jung, W.S.; Moon, H. G.; Baek, S.H.; Nahm, S.; Yoon,

329

S.J.; Kang, C.Y. Enhanced Piezoelectric Properties of Vertically Aligned

330

Single-crystalline NKN Nano-rod Arrays. Scientific Rep. 2015, 5.

331

(22) Purusothaman, Y.; Alluri, N. R.; Chandrasekhar, A.; Kim, S.J. Harnessing Low

332

Frequency-based Energy using a K0.5Na0.5NbO3 (KNN) Pigmented Piezoelectric

333

Paint System. J. Mater. Chem. C 2017, 5, 5501-5508.

334

(23) Chen, C.Y.; Liu, T.H.; Zhou, Y.; Zhang, Y.; Chueh, Y.L.; Chu, Y.H.; He, J.H.;

335

Wang, Z. L. Electricity Generation Based on Vertically Aligned PbZr0.2Ti0.8O3

336

Nanowire Arrays. Nano Energy 2012, 1, 424-428.

337 338

(24) Chen, X.; Xu, S.; Yao, N.; Shi, Y. 1.6 V Nanogenerator for Mechanical Energy Harvesting Using PZT Nanofibers. Nano Lett. 2010, 10, 2133-2137.

339

(25) Kingon, A. I.; Srinivasan, S. Lead Zirconate Titanate Thin Films Directly on

340

Copper Electrodes for Ferroelectric, Dielectric and Piezoelectric Applications.

341

Nature Mater. 2005, 4, 233-237.

342

(26) Wu, W.; Bai, S.; Yuan, M.; Qin, Y.; Wang, Z. L.; Jing, T. Lead Zirconate Titanate

343

Nanowire

Textile Nanogenerator for Wearable Energy-harvesting

344

Self-powered Devices. ACS Nano 2012, 6, 6231-6235.

and

345

(27) Nafari, A.; Bowland, C. C.; Sodano, H. A. Ultra-long Vertically Aligned Lead

346

Titanate Nanowire Arrays for Energy Harvesting in Extreme Environments.

347

Nano Energy 2017, 31, 168-173. 17 ACS Paragon Plus Environment

ACS Applied Nano Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

348 349

(28) Xu, S.; Hansen, B. J.; Wang, Z. L. Piezoelectric-nanowire-enabled Power Source for Driving Wireless Microelectronics. Nature Commun. 2010, 1, 93.

350

(29) Zhao, Q.L.; He, G.P.; Di, J.J.; Song, W.L.; Hou, Z.L.; Tan, P.P.; Wang, D.W.;

351

Cao, M.S. Flexible Semitransparent Energy Harvester with High Pressure

352

Sensitivity and Power Density Based on Laterally Aligned PZT Single-Crystal

353

Nanowires. ACS Appl. Mater. Interfaces 2017, 9, 24696-24703.

354

(30) Hou, T.C.; Yang, Y.; Lin, Z.H.; Ding, Y.; Park, C.; Pradel, K. C.; Chen, L.J.; Lin

355

Wang, Z. Nanogenerator Based on Zinc Blende CdTe Micro/nanowires. Nano

356

Energy 2013, 2, 387-393.

357

(31) Koka, A.; Sodano, H. A. High-sensitivity Accelerometer Composed of

358

Ultra-long Vertically Aligned Barium Titanate Nanowire Arrays. Nature

359

Commun. 2013, 4, 2682.

360 361 362 363

(32) Koka, A.; Zhou, Z.; Sodano, H. A. Vertically Aligned BaTiO3 Nanowire Arrays for Energy Harvesting. Energy Environ. Sci. 2014, 7, 288-296. (33) Xu, S.; Poirier, G.; Yao, N. PMN-PT Nanowires with a Very High Piezoelectric Constant. Nano Lett. 2012, 12, 2238-2242.

364

(34) Xu, S.; Yeh, Y.W.; Poirier, G.; McAlpine, M. C.; Register, R. A.; Yao, N.

365

Flexible Piezoelectric PMN–PT Nanowire-based Nanocomposite and Device.

366

Nano Lett. 2013, 13, 2393-2398.

367

(35) Ren, X.; Fan, H.; Zhao, Y.; Liu, Z. Flexible Lead-free BiFeO3/PDMS-based

368

Nanogenerator as Piezoelectric Energy Harvester. ACS Appl. Mater. Interfaces

369

2016, 8, 26190-26197. 18 ACS Paragon Plus Environment

Page 18 of 29

Page 19 of 29 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

ACS Applied Nano Materials

370

(36) Li, Q.; Cao, Y.; Yu, P.; Vasudevan, R.; Laanait, N.; Tselev, A.; Xue, F.; Chen, L.;

371

Maksymovych, P.; Kalinin, S. Giant Elastic Tunability in Strained BiFeO3 Near

372

an Electrically Induced Phase Transition. Nature Commun. 2015, 6.

373

(37) You, Y.M.; Liao, W.Q.; Zhao, D.; Ye, H.Y.; Zhang, Y.; Zhou, Q.; Niu, X.; Wang,

374

J.; Li, P.F.; Fu, D.W. An Organic-inorganic Perovskite Ferroelectric with Large

375

Piezoelectric Response. Science 2017, 357, 306-309.

376 377

(38) Guo, R.; Cross, L.; Park, S.; Noheda, B.; Cox, D.; Shirane, G. Origin of the High Piezoelectric Response in PbZr1- xTixO3. Phys. Rev. Lett. 2000, 84, 5423-5426.

378

(39) Chen, X.; Xu, S.; Yao, N.; Xu, W.; Shi, Y. Potential Measurement from a Single

379

Lead Ziroconate Titanate Nanofiber using a Nanomanipulator. Appl. Phys. Lett.

380

2009, 94, 253113.

381 382

(40) Wu, W.; Wang, Z. L. Piezotronics and Piezo-phototronics for Adaptive Electronics and Optoelectronics. Nature Rev. Mater. 2016, 1, 16031.

383

(41) Yang, X.; Daoud, W. A. Synergetic Effects in Composite-based Flexible Hybrid

384

Mechanical Energy Harvesting Generator. J. Mater. Chem. A 2017, 5,

385

9113-9121.

386

(42) Yan, J.; Jeong, Y. G. High Performance Flexible Piezoelectric Nanogenerators

387

based on BaTiO3 Nanofibers in Different Alignment Modes. ACS Appl. Mater.

388

Interfaces 2016, 8, 15700–15709.

389

(43) Park, K. I.; Lee, M.; Liu, Y.; Moon, S.; Hwang, G. T.; Zhu, G.; Kim, J. E.; Kim,

390

S. O.; Kim, D. K.; Wang, Z. L. Flexible Nanocomposite Generator Made of

391

BaTiO3 Nanoparticles and Graphitic Carbons. Adv. Mater. 2012, 24, 2999-3004. 19 ACS Paragon Plus Environment

ACS Applied Nano Materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

392

(44) Jung, J. H.; Lee, M.; Hong, J.I.; Ding, Y.; Chen, C.Y.; Chou, L.J.; Wang, Z. L.

393

Lead-free NaNbO3 Nanowires for a High Output Piezoelectric Nanogenerator.

394

ACS Nano 2011, 5, 10041-10046.

395

(45) Zhou, Z.; Bowland, C. C.; Malakooti, M. H.; Tang, H.; Sodano, H. A. Lead-free

396

0.5Ba (Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 Nanowires for Energy Harvesting.

397

Nanoscale 2016, 8, 5098-5105.

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Figure captions Figure 1. The XRD pattern of the hierarchical PZT nanowires sample. Figure 2. The SEM images of product synthesized hierarchical PZT nanowires: (a) Low magnification, and (b) high magnification images. Figure 3. The SEM images of products obtained with different amounts of Pb(NO3)2: (a, b) 3 mmol, and (c, d) 5 mmol. Figure 4. The SEM images of products synthesized by using precursors with different Zr: Ti ratio: (a, b) 0: 1; (c, d) 1: 9, and (e, f) 2: 8. Figure 5. The SEM images of products synthesized using different temperature: (a, b) 170 °C; (c, d) 185 °C; and (e, f) 210 °C. Figure 6. Schematic diagram of the energy harvester device fabrication process: (a) acrylic sheet substrate, (b) PZT-PDMS composite thin film cured by spin-coating, (c) peeled off the composite thin film from the acrylic sheet substrate, (d) PZT-PDMS film attachment on the brass beam top, and (e) conductor silver epoxy coated on the PZT-PDMS film. Figure 7. Sinusoidal excitation on hierarchical PZT nanowires energy harvester device: (a) open-circuit voltage generation under different vibration frequencies, (b) open-circuit peak to peak voltage versus vibration frequencies, (c) open-circuit voltage under different RMS sinusoidal acceleration input at resonant frequency (25.2 Hz), and (d) the power delivered to the load resistors versus the load resistance.

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